Historical warming reduced due to enhanced land carbon uptake.

PubMed

Shevliakova, Elena; Stouffer, Ronald J; Malyshev, Sergey; Krasting, John P; Hurtt, George C; Pacala, Stephen W

2013-10-15

Previous studies have demonstrated the importance of enhanced vegetation growth under future elevated atmospheric CO2 for 21st century climate warming. Surprisingly no study has completed an analogous assessment for the historical period, during which emissions of greenhouse gases increased rapidly and land-use changes (LUC) dramatically altered terrestrial carbon sources and sinks. Using the Geophysical Fluid Dynamics Laboratory comprehensive Earth System Model ESM2G and a reconstruction of the LUC, we estimate that enhanced vegetation growth has lowered the historical atmospheric CO2 concentration by 85 ppm, avoiding an additional 0.31 ± 0.06 °C warming. We demonstrate that without enhanced vegetation growth the total residual terrestrial carbon flux (i.e., the net land flux minus LUC flux) would be a source of 65-82 Gt of carbon (GtC) to atmosphere instead of the historical residual carbon sink of 186-192 GtC, a carbon saving of 251-274 GtC.

Requirement of the isocitrate lyase gene ICL1 for VPS41-mediated starvation response in Cryptococcus neoformans.

PubMed

Xu, Zhe; Zhi, Yafei; Dong, Jianzhang; Lin, Benfeng; Ye, Di; Liu, Xiaoguang

2016-07-01

Cryptococcus neoformans is a major cause of fungal meningitis in individuals with impaired immunity. Our previous studies have shown that the VPS41 gene plays a critical role in the survival of Cryptococcus neoformans under nitrogen starvation; however, the molecular mechanisms underlying VPS41-mediated starvation response remain to be elucidated. In the present study, we show that, under nitrogen starvation, VPS41 strongly enhanced ICL1 expression in C. neoformans and that overexpression of ICL1 in the vps41 mutant dramatically suppressed its defects in starvation response due to the loss of VPS41 function. Moreover, targeted deletion of ICL1 resulted in a dramatic decline in viability of C. neoformans cells under nitrogen deprivation. Taken together, our data suggest a model in which VPS41 up-regulates ICL1 expression, directly or indirectly, to promote survival of C. neoformans under nitrogen starvation.

Photovoltaic Performance of a Nanowire/Quantum Dot Hybrid Nanostructure Array Solar Cell.

PubMed

Wu, Yao; Yan, Xin; Zhang, Xia; Ren, Xiaomin

2018-02-23

An innovative solar cell based on a nanowire/quantum dot hybrid nanostructure array is designed and analyzed. By growing multilayer InAs quantum dots on the sidewalls of GaAs nanowires, not only the absorption spectrum of GaAs nanowires is extended by quantum dots but also the light absorption of quantum dots is dramatically enhanced due to the light-trapping effect of the nanowire array. By incorporating five layers of InAs quantum dots into a 500-nm high-GaAs nanowire array, the power conversion efficiency enhancement induced by the quantum dots is six times higher than the power conversion efficiency enhancement in thin-film solar cells which contain the same amount of quantum dots, indicating that the nanowire array structure can benefit the photovoltaic performance of quantum dot solar cells.

Enhancement in photoluminescence performance of carbon-decorated T-ZnO

NASA Astrophysics Data System (ADS)

Jian, Xian; Chen, Guozhang; Wang, Chao; Yin, Liangjun; Li, Gang; Yang, Ping; Chen, Lei; Xu, Bao; Gao, Yang; Feng, Yanyu; Tang, Hui; Luan, Chunhong; Liang, Yinglin; Jiang, Jing; Cao, Yu; Wang, Siyuan; Gao, Xin

2015-03-01

The facile preparation of ZnO possessing high visible luminescence intensity remains challenging due to an unclear luminescence mechanism. Here, two basic approaches are proposed to enhance the luminescent intensity based on the theoretical analysis over surface defects. Based on the deduction, we introduce a methodology for obtaining hybrid tetrapod-like zinc oxide (T-ZnO), decorated by carbon nanomarterials on T-ZnO surfaces through the catalytic chemical vapor deposition approach. The intensity of the T-ZnO green emission can be modulated by topography and the proportion of carbon. Under proper experiment conditions, the carbon decorating leads to dramatically enhanced luminescence intensity of T-ZnO from 400 to 700 nm compared with no carbon decorated, which elevates this approach to a simple and effective method for the betterment of fluorescent materials in practical applications.

Photovoltaic Performance of a Nanowire/Quantum Dot Hybrid Nanostructure Array Solar Cell

NASA Astrophysics Data System (ADS)

Wu, Yao; Yan, Xin; Zhang, Xia; Ren, Xiaomin

2018-02-01

An innovative solar cell based on a nanowire/quantum dot hybrid nanostructure array is designed and analyzed. By growing multilayer InAs quantum dots on the sidewalls of GaAs nanowires, not only the absorption spectrum of GaAs nanowires is extended by quantum dots but also the light absorption of quantum dots is dramatically enhanced due to the light-trapping effect of the nanowire array. By incorporating five layers of InAs quantum dots into a 500-nm high-GaAs nanowire array, the power conversion efficiency enhancement induced by the quantum dots is six times higher than the power conversion efficiency enhancement in thin-film solar cells which contain the same amount of quantum dots, indicating that the nanowire array structure can benefit the photovoltaic performance of quantum dot solar cells.

Fructose, Glucocorticoids and Adipose Tissue: Implications for the Metabolic Syndrome.

PubMed

Legeza, Balázs; Marcolongo, Paola; Gamberucci, Alessandra; Varga, Viola; Bánhegyi, Gábor; Benedetti, Angiolo; Odermatt, Alex

2017-04-26

The modern Western society lifestyle is characterized by a hyperenergetic, high sugar containing food intake. Sugar intake increased dramatically during the last few decades, due to the excessive consumption of high-sugar drinks and high-fructose corn syrup. Current evidence suggests that high fructose intake when combined with overeating and adiposity promotes adverse metabolic health effects including dyslipidemia, insulin resistance, type II diabetes, and inflammation. Similarly, elevated glucocorticoid levels, especially the enhanced generation of active glucocorticoids in the adipose tissue due to increased 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) activity, have been associated with metabolic diseases. Moreover, recent evidence suggests that fructose stimulates the 11β-HSD1-mediated glucocorticoid activation by enhancing the availability of its cofactor NADPH. In adipocytes, fructose was found to stimulate 11β-HSD1 expression and activity, thereby promoting the adipogenic effects of glucocorticoids. This article aims to highlight the interconnections between overwhelmed fructose metabolism, intracellular glucocorticoid activation in adipose tissue, and their metabolic effects on the progression of the metabolic syndrome.

Ion implantation enhanced metal-Si-metal photodetectors

NASA Astrophysics Data System (ADS)

Sharma, A. K.; Scott, K. A. M.; Brueck, S. R. J.; Zolper, J. C.; Myers, D. R.

1994-05-01

The quantum efficiency and frequency response of simple Ni-Si-Ni metal-semiconductor-metal (MSM) photodetectors at long wavelengths are significantly enhanced with a simple, ion-implantation step to create a highly absorbing region approx. 1 micron below the Si surface. The internal quantum efficiency is improved by a factor of approx. 3 at 860 nm (to 64%) and a full factor of ten at 1.06 microns (to 23%) as compared with otherwise identical unimplanted devices. Dark currents are only slightly affected by the implantation process and are as low as 630 pA for a 4.5-micron gap device at 10-V bias. Dramatic improvement in the impulse response is observed, 100 ps vs. 600 ps, also at 10-V bias and 4.5-micron gap, due to the elimination of carrier diffusion tails in the implanted devices. Due to its planar structure, this device is fully VLSI compatible. Potential applications include optical interconnections for local area networks and multi-chip modules.

Fructose, Glucocorticoids and Adipose Tissue: Implications for the Metabolic Syndrome

PubMed Central

Legeza, Balázs; Marcolongo, Paola; Gamberucci, Alessandra; Varga, Viola; Bánhegyi, Gábor; Benedetti, Angiolo; Odermatt, Alex

2017-01-01

The modern Western society lifestyle is characterized by a hyperenergetic, high sugar containing food intake. Sugar intake increased dramatically during the last few decades, due to the excessive consumption of high-sugar drinks and high-fructose corn syrup. Current evidence suggests that high fructose intake when combined with overeating and adiposity promotes adverse metabolic health effects including dyslipidemia, insulin resistance, type II diabetes, and inflammation. Similarly, elevated glucocorticoid levels, especially the enhanced generation of active glucocorticoids in the adipose tissue due to increased 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) activity, have been associated with metabolic diseases. Moreover, recent evidence suggests that fructose stimulates the 11β-HSD1-mediated glucocorticoid activation by enhancing the availability of its cofactor NADPH. In adipocytes, fructose was found to stimulate 11β-HSD1 expression and activity, thereby promoting the adipogenic effects of glucocorticoids. This article aims to highlight the interconnections between overwhelmed fructose metabolism, intracellular glucocorticoid activation in adipose tissue, and their metabolic effects on the progression of the metabolic syndrome. PMID:28445389

Effects of H2 Atmospheres on Sintering of Low Alloy Steels Containing Oxygen-Sensitive Masteralloys

NASA Astrophysics Data System (ADS)

de Oro Calderon, Raquel; Jaliliziyaeian, Maryam; Gierl-Mayer, Christian; Danninger, Herbert

2017-04-01

Processing of novel sintered steels with compositions including oxygen-sensitive elements requires deep understanding of the chemistry of sintering. The use of H2 atmospheres alleviates the oxygen transference from the base powder to the oxygen-sensitive particles. However, in H2, methane formation at 700-1200°C causes dramatic homogeneous decarburization of the part that affects both mechanical behavior and dimensional stability. The intensity and the critical temperatures of this effect depend strongly on the alloying elements, being significantly enhanced in presence of Si. When combining the alloying elements as Fe-Mn-Si masteralloys, methane formation is enhanced around 760°C due to the high Mn content (40 wt.%) in the masteralloys. Nevertheless, the benefits of H2 towards oxide reduction can still be advantageously used if diluting it in the form of N2-H2 atmospheres, or if limiting the use of H2 to temperatures below 500°C. Thus, decarburization due to methane formation can be successfully controlled.

High response speed microfluidic ice valves with enhanced thermal conductivity and a movable refrigeration source

PubMed Central

Si, Chaorun; Hu, Songtao; Cao, Xiaobao; Wu, Weichao

2017-01-01

Due to their ease of fabrication, facile use and low cost, ice valves have great potential for use in microfluidic platforms. For this to be possible, a rapid response speed is key and hence there is still much scope for improvement in current ice valve technology. Therefore, in this study, an ice valve with enhanced thermal conductivity and a movable refrigeration source has been developed. An embedded aluminium cylinder is used to dramatically enhance the heat conduction performance of the microfluidic platform and a movable thermoelectric unit eliminates the thermal inertia, resulting in a faster cooling process. The proposed ice valve achieves very short closing times (0.37 s at 10 μL/min) and also operates at high flow rates (1150 μL/min). Furthermore, the response time of the valve decreased by a factor of 8 when compared to current state of the art technology. PMID:28084447

High response speed microfluidic ice valves with enhanced thermal conductivity and a movable refrigeration source

NASA Astrophysics Data System (ADS)

Si, Chaorun; Hu, Songtao; Cao, Xiaobao; Wu, Weichao

2017-01-01

Due to their ease of fabrication, facile use and low cost, ice valves have great potential for use in microfluidic platforms. For this to be possible, a rapid response speed is key and hence there is still much scope for improvement in current ice valve technology. Therefore, in this study, an ice valve with enhanced thermal conductivity and a movable refrigeration source has been developed. An embedded aluminium cylinder is used to dramatically enhance the heat conduction performance of the microfluidic platform and a movable thermoelectric unit eliminates the thermal inertia, resulting in a faster cooling process. The proposed ice valve achieves very short closing times (0.37 s at 10 μL/min) and also operates at high flow rates (1150 μL/min). Furthermore, the response time of the valve decreased by a factor of 8 when compared to current state of the art technology.

Wavelength and intensity dependence of recollision-enhanced multielectron effects in high-order harmonic generation

NASA Astrophysics Data System (ADS)

Abanador, Paul M.; Mauger, François; Lopata, Kenneth; Gaarde, Mette B.; Schafer, Kenneth J.

2018-04-01

Using a model molecular system (A2) with two active electrons restricted to one dimension, we examine high-order harmonic generation (HHG) enhanced by rescattering. Our results show that even at intensities well below the single ionization saturation, harmonics generated from the cation (A2+ ) can be significantly enhanced due to the rescattering of the electron that is initially ionized. This two-electron effect is manifested by the appearance of a secondary plateau and cutoff in the HHG spectrum, extending beyond the predicted cutoff in the single active electron approximation. We use our molecular model to investigate the wavelength dependence of rescattering enhanced HHG, which was first reported in a model atomic system [I. Tikhomirov, T. Sato, and K. L. Ishikawa, Phys. Rev. Lett. 118, 203202 (2017), 10.1103/PhysRevLett.118.203202]. We demonstrate that the HHG yield in the secondary cutoff is highly sensitive to the available electron rescattering energies as indicated by a dramatic scaling with respect to driving wavelength.

Historical warming reduced due to enhanced land carbon uptake

PubMed Central

Shevliakova, Elena; Stouffer, Ronald J.; Malyshev, Sergey; Krasting, John P.; Hurtt, George C.; Pacala, Stephen W.

2013-01-01

Previous studies have demonstrated the importance of enhanced vegetation growth under future elevated atmospheric CO2 for 21st century climate warming. Surprisingly no study has completed an analogous assessment for the historical period, during which emissions of greenhouse gases increased rapidly and land-use changes (LUC) dramatically altered terrestrial carbon sources and sinks. Using the Geophysical Fluid Dynamics Laboratory comprehensive Earth System Model ESM2G and a reconstruction of the LUC, we estimate that enhanced vegetation growth has lowered the historical atmospheric CO2 concentration by 85 ppm, avoiding an additional 0.31 ± 0.06 °C warming. We demonstrate that without enhanced vegetation growth the total residual terrestrial carbon flux (i.e., the net land flux minus LUC flux) would be a source of 65–82 Gt of carbon (GtC) to atmosphere instead of the historical residual carbon sink of 186–192 GtC, a carbon saving of 251–274 GtC. PMID:24062452

Lateral diffusion contributes to FRET from lanthanide-tagged membrane proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lan, Tien-Hung; Wu, Guangyu; Lambert, Nevin A., E-mail: nelambert@gru.edu

2015-08-14

Diffusion can enhance Förster resonance energy transfer (FRET) when donors or acceptors diffuse distances that are similar to the distances separating them during the donor's excited state lifetime. Lanthanide donors remain in the excited state for milliseconds, which makes them useful for time-resolved FRET applications but also allows time for diffusion to enhance energy transfer. Here we show that diffusion dramatically enhances FRET between membrane proteins labeled with lanthanide donors. This phenomenon complicates interpretation of experiments that use long-lived donors to infer association or proximity of mobile membrane proteins, but also offers a method of monitoring diffusion in membrane domainsmore » in real time in living cells. - Highlights: • Diffusion enhances TR-FRET from membrane proteins labeled with lanthanide donors. • Diffusion-dependent FRET can overshadow FRET due to oligomerization or clustering. • FRET studies using lanthanide-tagged membrane proteins should consider diffusion. • FRET from lanthanide donors can be used to monitor membrane protein diffusion.« less

Plasmonic Colloidal Nanoantennas for Tip-Enhanced Raman Spectrocopy

NASA Astrophysics Data System (ADS)

Dill, Tyler J.

Plasmonic nanoantennas that a support localized surface plasmon resonance (LSPR) are capable of confining visible light to subwavelength dimensions due to strong electromagnetic field enhancement at the probe tip. Nanoantenna enable optical methods such as tip-enhanced Raman spectroscopy (TERS), a technique that uses scanning probe microscopy tips to provide chemical information with nanoscale spatial resolution and single-molecule sensitivities. The LSPR supported by the probe tip is extremely sensitive to the nanoscale morphology of the nanoantenna. Control of nanoscale morphology is notoriously difficult to achieve, resulting in TERS probes with poor reproducibility. In my thesis, I demonstrate high-performance, predictable, and broadband nanospectroscopy probes that are fabricated by self-assembly. Shaped metal nanoparticles are organized into dense layers and deposited onto scanning probe tips. When coupled to a metal substrate, these probes support a strong optical resonance in the gap between the substrate and the probe, producing dramatic field enhancements. I show through experiment and electromagnetic modeling that close-packed but electrically isolated nanoparticles are electromagnetically coupled. Hybridized LSPRs supported by self-assembled nanoparticles with a broadband optical response, giving colloidal nanoantenna a high tolerance for geometric variation resulting from fabrication. I find that coupled nanoparticles act as a waveguide, transferring energy from many neighboring nanoparticles towards the active TERS apex. I also use surface-enhanced Raman spectroscopy (SERS) to characterize the effects of nanoparticle polydispersity and gap height on the Raman enhancement. These colloidal probes have consistently achieved dramatic Raman enhancements in the range of 108-109 with sub-50 nm spatial resolution. Furthermore, in contrast to other nanospectroscopy probes, these colloidal probes can be fabricated in a scalable fashion with a batch-to-batch reproducibility of 80%. This body of work serves as an important demonstration that bottom-up engineering can be used for batch fabricatation of high-performance and high-reliability devices using inexpensive equipment and materials.

Observation of Enhanced Hole Extraction in Br Concentration Gradient Perovskite Materials.

PubMed

Kim, Min-Cheol; Kim, Byeong Jo; Son, Dae-Yong; Park, Nam-Gyu; Jung, Hyun Suk; Choi, Mansoo

2016-09-14

Enhancing hole extraction inside the perovskite layer is the key factor for boosting photovoltaic performance. Realization of halide concentration gradient perovskite materials has been expected to exhibit rapid hole extraction due to the precise bandgap tuning. Moreover, a formation of Br-rich region on the tri-iodide perovskite layer is expected to enhance moisture stability without a loss of current density. However, conventional synthetic techniques of perovskite materials such as the solution process have not achieved the realization of halide concentration gradient perovskite materials. In this report, we demonstrate the fabrication of Br concentration gradient mixed halide perovskite materials using a novel and facile halide conversion method based on vaporized hydrobromic acid. Accelerated hole extraction and enhanced lifetime due to Br gradient was verified by observing photoluminescence properties. Through the combination of secondary ion mass spectroscopy and transmission electron microscopy with energy-dispersive X-ray spectroscopy analysis, the diffusion behavior of Br ions in perovskite materials was investigated. The Br-gradient was found to be eventually converted into a homogeneous mixed halide layer after undergoing an intermixing process. Br-substituted perovskite solar cells exhibited a power conversion efficiency of 18.94% due to an increase in open circuit voltage from 1.08 to 1.11 V and an advance in fill-factor from 0.71 to 0.74. Long-term stability was also dramatically enhanced after the conversion process, i.e., the power conversion efficiency of the post-treated device has remained over 97% of the initial value under high humid conditions (40-90%) without any encapsulation for 4 weeks.

Assessing the osteoblast transcriptome in a model of enhanced bone formation due to constitutive G{sub s}–G protein signaling in osteoblasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wattanachanya, Lalita, E-mail: lalita_md@yahoo.com; Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok; Wang, Liping, E-mail: lipingwang05@yahoo.com

G protein-coupled receptor (GPCR) signaling in osteoblasts (OBs) is an important regulator of bone formation. We previously described a mouse model expressing Rs1, an engineered constitutively active G{sub s}-coupled GPCR, under the control of the 2.3 kb Col I promoter. These mice showed a dramatic age-dependent increase in trabecular bone of femurs. Here, we further evaluated the effects of enhanced G{sub s} signaling in OBs on intramembranous bone formation by examining calvariae of 1- and 9-week-old Col1(2.3)/Rs1 mice and characterized the in vivo gene expression specifically occurring in osteoblasts with activated G{sub s} G protein-coupled receptor signaling, at the cellularmore » level rather than in a whole bone. Rs1 calvariae displayed a dramatic increase in bone volume with partial loss of cortical structure. By immunohistochemistry, Osterix was detected in cells throughout the inter-trabecular space while Osteocalcin was expressed predominantly in cells along bone surfaces, suggesting the role of paracrine mediators secreted from OBs driven by 2.3 kb Col I promoter could influence early OB commitment, differentiation, and/or proliferation. Gene expression analysis of calvarial OBs revealed that genes affected by Rs1 signaling include those encoding proteins important for cell differentiation, cytokines and growth factors, angiogenesis, coagulation, and energy metabolism. The set of G{sub s}-GPCRs and other GPCRs that may contribute to the observed skeletal phenotype and candidate paracrine mediators of the effect of G{sub s} signaling in OBs were also determined. Our results identify novel detailed in vivo cellular changes of the anabolic response of the skeleton to G{sub s} signaling in mature OBs. - Highlights: • OB expression of an engineered G{sub s}-coupled receptor dramatically increases bone mass. • We investigated the changes in gene expression in vivo in enhanced OB G{sub s} signaling. • Genes in cell cycle and transcription were increased in enhanced OB G{sub s} signaling. • GPCRs and paracrine mediators of the effect of G{sub s} signaling in OBs were determined.« less

Room temperature synthesis and enhanced photocatalytic property of CeO2/ZnO heterostructures

NASA Astrophysics Data System (ADS)

Wang, Chao; Fan, Huiqing; Ren, Xiaohu; Fang, Jiawen

2018-02-01

To achieve better photocatalytic performance, we proposed a facile solid-state reaction method to produce CeO2/ZnO heterostructures. Ceria and zinc oxide were synthesized simultaneously by thoroughly grinding the mixture of zinc acetate dihydrate, cerium nitrate hexahydrate and sodium hydroxide. The morphology of the as-prepared heterostructures varies dramatically as different amount of ceria was introduced in the composition. The photocatalytic performance of CeO2/ZnO heterojunctions was 4.6 times higher than that of pure ZnO. The enhanced photocatalytic activity could be ascribed to that more electrons and holes could transport to the surface of catalysts and react with the pollution due to the extended light-responsive range, accelerated migration, increased specific surface area and suppressed recombination of photogenerated carriers.

Ferroelectric enhancement in heterostructured ZnO /BiFeO3-PbTiO3 film

NASA Astrophysics Data System (ADS)

Yu, Shengwen; Chen, Rui; Zhang, Guanjun; Cheng, Jinrong; Meng, Zhongyan

2006-11-01

The authors have prepared heterostructured ZnO /BiFeO3-PbTiO3 (BFO-PT) composite film and BFO-PT film on Pt /Ti/SiO2/Si substrates by pulsed-laser deposition. The structure and morphologies of the films were characterized by x-ray diffraction (XRD) and scanning electron microscope. XRD results show that both films are perovskite structured last with different orientations. The leakage current density in the ZnO /BFO-PT film was found to be nearly two orders of magnitude lower. This could be due to the introduced ZnO layer behaving as a Schottky barrier between the BFO-PT film and top electrodes. The dramatic ferroelectric enhancement in ZnO /BFO-PT film is mostly ascribed to the improved insulation.

Regulated Breathing Effect of Silicon Negative Electrode for Dramatically Enhanced Performance of Li-Ion Battery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao, Xingcheng; Zhou, Weidong; Kim, Youngnam

Si is an attractive negative electrode material for lithium ion batteries due to its high specifi c capacity (≈3600 mAh g –1 ). However, the huge volume swelling and shrinking during cycling, which mimics a breathing effect at the material/electrode/cell level, leads to several coupled issues including fracture of Si particles, unstable solid electrolyte interphase, and low Coulombic effi ciency. In this work, the regulation of the breathing effect is reported by using Si–C yolk–shell nanocomposite which has been well-developed by other researchers. The focus is on understanding how the nanoscaled materials design impacts the mechanical and electrochemical response atmore » electrode level. For the fi rst time, it is possible to observe one order of magnitude of reduction on breathing effect at the electrode level during cycling: the electrode thickness variation reduced down to 10%, comparing with 100% in the electrode with Si nanoparticles as active materials. The Si–C yolk–shell nanocomposite electrode exhibits excellent capacity retention and high cycle effi ciency. In situ transmission electron microscopy and fi nite element simulations consistently reveals that the dramatically enhanced performance is associated with the regulated breathing of the Si in the new composite, therefore the suppression of the overall electrode expansion.« less

Electrochemical Characterization of Riboflavin-Enhanced Reduction of Trinitrotoluene

PubMed Central

Sumner, James J.; Chu, Kevin

2011-01-01

There is great interest in understanding trinitrotoluene (TNT) and dinitrotoluene (DNT) contamination, detection and remediation in the environment due to TNT’s negative health effects and security implications. Numerous publications have focused on detecting TNT in groundwater using multiple techniques, including electrochemistry. The main degradation pathway of nitrotoluenes in the environment is reduction, frequently with biological and/or photolytic assistance. Riboflavin has also been noted to aid in TNT remediation in soils and groundwater when exposed to light. This report indicates that adding riboflavin to a TNT or DNT solution enhances redox currents in electrochemical experiments. Here AC voltammetry was performed and peak currents compared with and without riboflavin present. Results indicated that TNT, DNT and riboflavin could be detected using AC voltammetry on modified gold electrodes and the addition of riboflavin affected redox peaks of TNT and DNT. Poised potential experiments indicated that it is possible to enhance reduction of TNT in the presence of riboflavin and light. These results were dramatic enough to explain long term enhancement of bioremediation in environments containing high levels of riboflavin and enhance the limit of detection in electrochemically-based nitrotoluene sensing. PMID:22346674

Observation of ionization enhancement in two-color circularly polarized laser fields

NASA Astrophysics Data System (ADS)

Mancuso, Christopher A.; Dorney, Kevin M.; Hickstein, Daniel D.; Chaloupka, Jan L.; Tong, Xiao-Min; Ellis, Jennifer L.; Kapteyn, Henry C.; Murnane, Margaret M.

2017-08-01

When atoms are irradiated by two-color circularly polarized laser fields the resulting strong-field processes are dramatically different than when the same atoms are irradiated by a single-color ultrafast laser. For example, electrons can be driven in complex two-dimensional trajectories before rescattering or circularly polarized high harmonics can be generated, which was once thought impossible. Here, we show that two-color circularly polarized lasers also enable control over the ionization process itself and make a surprising finding: the ionization rate can be enhanced by up to 700 % simply by switching the relative helicity of the two-color circularly polarized laser field. This enhancement is experimentally observed in helium, argon, and krypton over a wide range of intensity ratios of the two-color field. We use a combination of advanced quantum and fully classical calculations to explain this ionization enhancement as resulting in part due to the increased density of excited states available for resonance-enhanced ionization in counter-rotating fields compared with co-rotating fields. In the future, this effect could be used to probe the excited state manifold of complex molecules.

Interaction of nanosecond ultraviolet laser pulses with reactive dusty plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wetering, F. M. J. H. van de; Oosterbeek, W.; Beckers, J.

2016-05-23

Even though UV laser pulses that irradiate a gas discharge are small compared to the plasma volume (≲3%) and plasma-on time (≲6 × 10{sup −6}%), they are found to dramatically change the discharge characteristics on a global scale. The reactive argon–acetylene plasma allows the growth of nanoparticles with diameters up to 1 μm, which are formed inside the discharge volume due to spontaneous polymerization reactions. It is found that the laser pulses predominantly accelerate and enhance the coagulation phase and are able to suppress the formation of a dust void.

Increasing ENSO-Driven Drought and Wildfire Risks in a Warming Climate

NASA Astrophysics Data System (ADS)

Fasullo, J.; Otto-Bliesner, B. L.; Stevenson, S.

2015-12-01

ENSO-related teleconnections occurring in the transient climate states of the 20th and 21st centuries are examined using the NCAR CESM1-CAM5 Large Ensemble (LE). A focus is given to quantifying the changing nature of related variability in a warming climate, the statistical robustness of which is enhanced by the numerous members of the LE (presently ~40). It is found that while the dynamical components of ENSO's teleconnections weaken considerably in a warming world, associated variability over land is in many cases sustained by changes in the background state, such as for rainfall due to the background rise in specific humidity. In some fields, particularly those associated with associated with thermal stress (e.g. drought and wildfire), ENSO-related variance increases dramatically. This, combined with the fact that ENSO variance itself increases in a warming climate in the LE, contributes to dramatic projected increases in ENSO-driven drought and wildfire risks in a warming world.

Simple inflationary models in Gauss-Bonnet brane-world cosmology

NASA Astrophysics Data System (ADS)

Okada, Nobuchika; Okada, Satomi

2016-06-01

In light of the recent Planck 2015 results for the measurement of the cosmic microwave background (CMB) anisotropy, we study simple inflationary models in the context of the Gauss-Bonnet (GB) brane-world cosmology. The brane-world cosmological effect modifies the power spectra of scalar and tensor perturbations generated by inflation and causes a dramatic change for the inflationary predictions of the spectral index (n s) and the tensor-to-scalar ratio (r) from those obtained in the standard cosmology. In particular, the predicted r values in the inflationary models favored by the Planck 2015 results are suppressed due to the GB brane-world cosmological effect, which is in sharp contrast with inflationary scenario in the Randall-Sundrum brane-world cosmology, where the r values are enhanced. Hence, these two brane-world cosmological scenarios are distinguishable. With the dramatic change of the inflationary predictions, the inflationary scenario in the GB brane-world cosmology can be tested by more precise measurements of n s and future observations of the CMB B-mode polarization.

Regulation of apoptosis in human melanoma and neuroblastoma cells by statins, sodium arsenite and TRAIL: a role of combined treatment versus monotherapy

PubMed Central

Ivanov, Vladimir N.; Hei, Tom K.

2015-01-01

Treatment of melanoma cells by sodium arsenite or statins (simvastatin and lovastatin) dramatically modified activities of the main cell signaling pathways resulting in the induction of heme oxygenase-1 (HO-1) and in a downregulation of cyclooxygenase-2 (COX-2) protein levels. Through heme degradation and the production of carbon monoxide and biliverdin, HO-1 plays a protective role in different scenario of oxidative stress followed by mitochondrial apoptosis. Both sodium arsenite and statins could be efficient inducers of apoptosis in some melanoma cell lines, but often exhibited only modest proapoptotic activity in others, due to numerous protective mechanisms. We demonstrated in the present study that treatment by sodium arsenite or statins with an additional inhibition of HO-1 expression (or activation) caused a substantial upregulation of apoptosis in melanoma cells. Sodium arsenite- or statin-induced apoptosis was independent of BRAF status (wild type versus V600E) in melanoma lines. Monotreatment required high doses of statins (20–40 μM) for effective induction of apoptosis. As an alternative approach, pretreatment of melanoma cells with statin at decreased doses (5–20 μM) dramatically enhanced TRAIL-induced apoptosis, due to suppression of the NF-κB and STAT3-transcriptional targets (including COX-2) and downregulation of cFLIP-L (a caspase-8 inhibitor) protein levels. Furthermore, combined treatment with sodium arsenite and TRAIL or simvastatin and TRAIL efficiently induced apoptotic commitment in human neuroblastoma cells. In summary, our findings on enhancing effects of combined treatment of cancer cells using statin and TRAIL provide the rationale for further preclinical evaluation. PMID:21910007

Heat and corrosion resistant cast CF8C stainless steel with improved high temperature strength and ductility

DOEpatents

Maziasz, Philip J.; McGreevy, Tim; Pollard, Michael James; Siebenaler, Chad W.; Swindeman, Robert W.

2006-12-26

A CF8C type stainless steel alloy and articles formed therefrom containing about 18.0 weight percent to about 22.0 weight percent chromium and 11.0 weight percent to about 14.0 weight percent nickel; from about 0.05 weight percent to about 0.15 weight percent carbon; from about 2.0 weight percent to about 10.0 weight percent manganese; and from about 0.3 weight percent to about 1.5 weight percent niobium. The present alloys further include less than 0.15 weight percent sulfur which provides high temperature strength both in the matrix and at the grain boundaries without reducing ductility due to cracking along boundaries with continuous or nearly-continuous carbides. The disclosed alloys also have increased nitrogen solubility thereby enhancing strength at all temperatures because nitride precipitates or nitrogen porosity during casting are not observed. The solubility of nitrogen is dramatically enhanced by the presence of manganese, which also retains or improves the solubility of carbon thereby providing additional solid solution strengthening due to the presence of manganese and nitrogen, and combined carbon.

Heat and corrosion resistant cast CF8C stainless steel with improved high temperature strength and ductility

DOEpatents

Maziasz, Philip J.; McGreevy, Tim; Pollard, Michael James; Siebenaler, Chad W.; Swindeman, Robert W.

2010-08-17

A CF8C type stainless steel alloy and articles formed therefrom containing about 18.0 weight percent to about 22.0 weight percent chromium and 11.0 weight percent to about 14.0 weight percent nickel; from about 0.05 weight percent to about 0.15 weight percent carbon; from about 2.0 weight percent to about 10.0 weight percent manganese; and from about 0.3 weight percent to about 1.5 weight percent niobium. The present alloys further include less than 0.15 weight percent sulfur which provides high temperature strength both in the matrix and at the grain boundaries without reducing ductility due to cracking along boundaries with continuous or nearly-continuous carbides. The disclosed alloys also have increased nitrogen solubility thereby enhancing strength at all temperatures because nitride precipitates or nitrogen porosity during casting are not observed. The solubility of nitrogen is dramatically enhanced by the presence of manganese, which also retains or improves the solubility of carbon thereby providing additional solid solution strengthening due to the presence of manganese and nitrogen, and combined carbon.

Deconvoluting the Photonic and Electronic Response of 2D Materials: The Case of MoS2.

PubMed

Zhang, Kehao; Borys, Nicholas J; Bersch, Brian M; Bhimanapati, Ganesh R; Xu, Ke; Wang, Baoming; Wang, Ke; Labella, Michael; Williams, Teague A; Haque, Md Amanul; Barnard, Edward S; Fullerton-Shirey, Susan; Schuck, P James; Robinson, Joshua A

2017-12-05

Evaluating and tuning the properties of two-dimensional (2D) materials is a major focus of advancing 2D science and technology. While many claim that the photonic properties of a 2D layer provide evidence that the material is "high quality", this may not be true for electronic performance. In this work, we deconvolute the photonic and electronic response of synthetic monolayer molybdenum disulfide. We demonstrate that enhanced photoluminescence can be robustly engineered via the proper choice of substrate, where growth of MoS 2 on r-plane sapphire can yield >100x enhancement in PL and carrier lifetime due to increased molybdenum-oxygen bonding compared to that of traditionally grown MoS 2 on c-plane sapphire. These dramatic enhancements in optical properties are similar to those of super-acid treated MoS 2 , and suggest that the electronic properties of the MoS 2 are also superior. However, a direct comparison of the charge transport properties indicates that the enhanced PL due to increased Mo-O bonding leads to p-type compensation doping, and is accompanied by a 2x degradation in transport properties compared to MoS 2 grown on c-plane sapphire. This work provides a foundation for understanding the link between photonic and electronic performance of 2D semiconducting layers, and demonstrates that they are not always correlated.

Deconvoluting the Photonic and Electronic Response of 2D Materials: The Case of MoS 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Kehao; Borys, Nicholas J.; Bersch, Brian M.

Evaluating and tuning the properties of two-dimensional (2D) materials is a major focus of advancing 2D science and technology. While many claim that the photonic properties of a 2D layer provide evidence that the material is "high quality", this may not be true for electronic performance. In this work, we deconvolute the photonic and electronic response of synthetic monolayer molybdenum disulfide. We demonstrate that enhanced photoluminescence can be robustly engineered via the proper choice of substrate, where growth of MoS 2 on r-plane sapphire can yield > 100x enhancement in PL and carrier lifetime due to increased molybdenum-oxygen bonding comparedmore » to that of traditionally grown MoS 2 on c-plane sapphire. These dramatic enhancements in optical properties are similar to those of super-acid treated MoS 2 , and suggest that the electronic properties of the MoS 2 are also superior. However, a direct comparison of the charge transport properties indicates that the enhanced PL due to increased Mo-O bonding leads to p-type compensation doping, and is accompanied by a 2x degradation in transport properties compared to MoS 2 grown on c-plane sapphire. This work provides a foundation for understanding the link between photonic and electronic performance of 2D semiconducting layers, and demonstrates that they are not always correlated.« less

Deconvoluting the Photonic and Electronic Response of 2D Materials: The Case of MoS 2

DOE PAGES

Zhang, Kehao; Borys, Nicholas J.; Bersch, Brian M.; ...

2017-12-05

Evaluating and tuning the properties of two-dimensional (2D) materials is a major focus of advancing 2D science and technology. While many claim that the photonic properties of a 2D layer provide evidence that the material is "high quality", this may not be true for electronic performance. In this work, we deconvolute the photonic and electronic response of synthetic monolayer molybdenum disulfide. We demonstrate that enhanced photoluminescence can be robustly engineered via the proper choice of substrate, where growth of MoS 2 on r-plane sapphire can yield > 100x enhancement in PL and carrier lifetime due to increased molybdenum-oxygen bonding comparedmore » to that of traditionally grown MoS 2 on c-plane sapphire. These dramatic enhancements in optical properties are similar to those of super-acid treated MoS 2 , and suggest that the electronic properties of the MoS 2 are also superior. However, a direct comparison of the charge transport properties indicates that the enhanced PL due to increased Mo-O bonding leads to p-type compensation doping, and is accompanied by a 2x degradation in transport properties compared to MoS 2 grown on c-plane sapphire. This work provides a foundation for understanding the link between photonic and electronic performance of 2D semiconducting layers, and demonstrates that they are not always correlated.« less

One-process fabrication of metal hierarchical nanostructures with rich nanogaps for highly-sensitive surface-enhanced Raman scattering.

PubMed

Liu, Gui-qiang; Yu, Mei-dong; Liu, Zheng-qi; Liu, Xiao-shan; Huang, Shan; Pan, Ping-ping; Wang, Yan; Liu, Mu-lin; Gu, Gang

2015-05-08

One-process fabrication of highly active and reproducible surface-enhanced Raman scattering (SERS) substrates via ion beam deposition is reported. The fabricated metal-dielectric-metal (MDM) hierarchical nanostructure possesses rich nanogaps and a tunable resonant cavity. Raman scattering signals of analytes are dramatically strengthened due to the strong near-field coupling of localized surface plasmon resonances (LSPRs) and the strong interaction of LSPRs of metal NPs with surface plasmon polaritons (SPPs) on the underlying metal film by crossing over the dielectric spacer. The maximum Raman enhancement for the highest Raman peak at 1650 cm(-1) is 13.5 times greater than that of a single metal nanoparticle (NP) array. Moreover, the SERS activity can be efficiently tailored by varying the size and number of voids between adjacent metal NPs and the thickness of the dielectric spacer. These findings may broaden the scope of SERS applications of MDM hierarchical nanostructures in biomedical and analytical chemistry.

Antimycotic-Antibiotic Amphotericin B Promotes Influenza Virus Replication in Cell Culture ▿

PubMed Central

Roethl, Elisabeth; Gassner, Manuela; Krenn, Brigitte M.; Romanovskaya-Romanko, Ekaterina A.; Seper, Helena; Romanova, Julia; Nakowitsch, Sabine; Sturlan, Sanda; Wolschek, Markus; Sirotkin, Alexej; Kiselev, Oleg; Muster, Thomas; Egorov, Andrej

2011-01-01

In general, antibiotics are not rated as substances that inhibit or support influenza virus replication. We describe here the enhancing effect of the polyene antibiotic amphotericin B (AmB) on influenza virus growth in Vero cells. We show that isolation rates of influenza A and B viruses from clinical samples can be dramatically enhanced by adding AmB to the culture medium. We demonstrate that AmB promotes the viral uptake and endocytic processing of the virus particles. This effect is specific for Vero and human nasal epithelial cells and was not observed in Madin-Darby canine kidney cells. The effect of AmB was subtype specific and more prominent for human seasonal influenza strains but absent for H5N1 human viruses. The AmB-enhancing effect seemed to be solely due to the viral hemagglutinin function. Our results indicate that the use of AmB may facilitate influenza virus isolation and production in Vero cells. PMID:21849438

Multiscale Modeling of Plasmon-Enhanced Power Conversion Efficiency in Nanostructured Solar Cells.

PubMed

Meng, Lingyi; Yam, ChiYung; Zhang, Yu; Wang, Rulin; Chen, GuanHua

2015-11-05

The unique optical properties of nanometallic structures can be exploited to confine light at subwavelength scales. This excellent light trapping is critical to improve light absorption efficiency in nanoscale photovoltaic devices. Here, we apply a multiscale quantum mechanics/electromagnetics (QM/EM) method to model the current-voltage characteristics and optical properties of plasmonic nanowire-based solar cells. The QM/EM method features a combination of first-principles quantum mechanical treatment of the photoactive component and classical description of electromagnetic environment. The coupled optical-electrical QM/EM simulations demonstrate a dramatic enhancement for power conversion efficiency of nanowire solar cells due to the surface plasmon effect of nanometallic structures. The improvement is attributed to the enhanced scattering of light into the photoactive layer. We further investigate the optimal configuration of the nanostructured solar cell. Our QM/EM simulation result demonstrates that a further increase of internal quantum efficiency can be achieved by scattering light into the n-doped region of the device.

Enhancing stability and efficiency of perovskite solar cells with crosslinkable silane-functionalized and doped fullerene

DOE PAGES

Bai, Yang; Dong, Qingfeng; Shao, Yuchuan; ...

2016-10-05

The instability of hybrid perovskite materials due to water and moisture arises as one major challenge to be addressed before any practical application of the demonstrated high efficiency perovskite solar cells. Here we report a facile strategy that can simultaneously enhance the stability and efficiency of p-i-n planar heterojunction-structure perovskite devices. Crosslinkable silane molecules with hydrophobic functional groups are bonded onto fullerene to make the fullerene layer highly water-resistant. Methylammonium iodide is introduced in the fullerene layer for n-doping via anion-induced electron transfer, resulting in dramatically increased conductivity over 100-fold. With crosslinkable silane-functionalized and doped fullerene electron transport layer, themore » perovskite devices deliver an efficiency of 19.5% with a high fill factor of 80.6%. Furthermore, a crosslinked silane-modified fullerene layer also enhances the water and moisture stability of the non-sealed perovskite devices by retaining nearly 90% of their original efficiencies after 30 days’ exposure in an ambient environment.« less

Coarse cluster enhancing collaborative recommendation for social network systems

NASA Astrophysics Data System (ADS)

Zhao, Yao-Dong; Cai, Shi-Min; Tang, Ming; Shang, Min-Sheng

2017-10-01

Traditional collaborative filtering based recommender systems for social network systems bring very high demands on time complexity due to computing similarities of all pairs of users via resource usages and annotation actions, which thus strongly suppresses recommending speed. In this paper, to overcome this drawback, we propose a novel approach, namely coarse cluster that partitions similar users and associated items at a high speed to enhance user-based collaborative filtering, and then develop a fast collaborative user model for the social tagging systems. The experimental results based on Delicious dataset show that the proposed model is able to dramatically reduce the processing time cost greater than 90 % and relatively improve the accuracy in comparison with the ordinary user-based collaborative filtering, and is robust for the initial parameter. Most importantly, the proposed model can be conveniently extended by introducing more users' information (e.g., profiles) and practically applied for the large-scale social network systems to enhance the recommending speed without accuracy loss.

Enhancing stability and efficiency of perovskite solar cells with crosslinkable silane-functionalized and doped fullerene

PubMed Central

Bai, Yang; Dong, Qingfeng; Shao, Yuchuan; Deng, Yehao; Wang, Qi; Shen, Liang; Wang, Dong; Wei, Wei; Huang, Jinsong

2016-01-01

The instability of hybrid perovskite materials due to water and moisture arises as one major challenge to be addressed before any practical application of the demonstrated high efficiency perovskite solar cells. Here we report a facile strategy that can simultaneously enhance the stability and efficiency of p–i–n planar heterojunction-structure perovskite devices. Crosslinkable silane molecules with hydrophobic functional groups are bonded onto fullerene to make the fullerene layer highly water-resistant. Methylammonium iodide is introduced in the fullerene layer for n-doping via anion-induced electron transfer, resulting in dramatically increased conductivity over 100-fold. With crosslinkable silane-functionalized and doped fullerene electron transport layer, the perovskite devices deliver an efficiency of 19.5% with a high fill factor of 80.6%. A crosslinked silane-modified fullerene layer also enhances the water and moisture stability of the non-sealed perovskite devices by retaining nearly 90% of their original efficiencies after 30 days' exposure in an ambient environment. PMID:27703136

Signal enhancement and Patterson-search phasing for high-spatial-resolution coherent X-ray diffraction imaging of biological objects.

PubMed

Takayama, Yuki; Maki-Yonekura, Saori; Oroguchi, Tomotaka; Nakasako, Masayoshi; Yonekura, Koji

2015-01-28

In this decade coherent X-ray diffraction imaging has been demonstrated to reveal internal structures of whole biological cells and organelles. However, the spatial resolution is limited to several tens of nanometers due to the poor scattering power of biological samples. The challenge is to recover correct phase information from experimental diffraction patterns that have a low signal-to-noise ratio and unmeasurable lowest-resolution data. Here, we propose a method to extend spatial resolution by enhancing diffraction signals and by robust phasing. The weak diffraction signals from biological objects are enhanced by interference with strong waves from dispersed colloidal gold particles. The positions of the gold particles determined by Patterson analysis serve as the initial phase, and this dramatically improves reliability and convergence of image reconstruction by iterative phase retrieval. A set of calculations based on current experiments demonstrates that resolution is improved by a factor of two or more.

Signal enhancement and Patterson-search phasing for high-spatial-resolution coherent X-ray diffraction imaging of biological objects

PubMed Central

Takayama, Yuki; Maki-Yonekura, Saori; Oroguchi, Tomotaka; Nakasako, Masayoshi; Yonekura, Koji

2015-01-01

In this decade coherent X-ray diffraction imaging has been demonstrated to reveal internal structures of whole biological cells and organelles. However, the spatial resolution is limited to several tens of nanometers due to the poor scattering power of biological samples. The challenge is to recover correct phase information from experimental diffraction patterns that have a low signal-to-noise ratio and unmeasurable lowest-resolution data. Here, we propose a method to extend spatial resolution by enhancing diffraction signals and by robust phasing. The weak diffraction signals from biological objects are enhanced by interference with strong waves from dispersed colloidal gold particles. The positions of the gold particles determined by Patterson analysis serve as the initial phase, and this dramatically improves reliability and convergence of image reconstruction by iterative phase retrieval. A set of calculations based on current experiments demonstrates that resolution is improved by a factor of two or more. PMID:25627480

Interfacial reflection enhanced optical extinction and thermal dynamics in polymer nanocomposite films

NASA Astrophysics Data System (ADS)

Dunklin, Jeremy R.; Forcherio, Gregory T.; Berry, Keith R.; Roper, D. Keith

2016-09-01

Polymer films containing plasmonic nanostructures are of increasing interest for development of responsive energy, sensing, and therapeutic systems. A series of novel gold nanoparticle (AuNP)-polydimethylsiloxane (PDMS) films were fabricated to elucidate enhanced optical extinction from diffractive and scattering induced internal reflection. AuNPs with dramatically different scattering-to-absorption ratios were compared at variable interparticle separations to differentiate light trapping from optical diffraction and Mie scattering. Description of interfacial optical and thermal effects due to these interrelated contributions has progressed beyond Mie theory, Beer's law, effective media, and conventional heat transfer descriptions. Thermal dissipation rates in AuNP-PDMS with this interfacial optical reflection was enhanced relative to films containing heterogeneous AuNPs and a developed thermal dissipation description. This heuristic, which accounts for contributions of both internal and external thermal dissipations, has been shown to accurately predict thermal dissipation rates from AuNP-containing insulating and conductive substrates in both two and three-dimensional systems. Enhanced thermal response rates could enable design and adaptive control of thermoplasmonic materials for a variety of implementations.

Enhancing the High-Voltage Cycling Performance of LiNi1/3Co1/3Mn1/3O2/Graphite Batteries Using Alkyl 3,3,3-Trifluoropropanoate as an Electrolyte Additive.

PubMed

Zheng, Xiangzhen; Huang, Tao; Pan, Ying; Wang, Wenguo; Fang, Guihuang; Ding, Kaining; Wu, Maoxiang

2017-06-07

The present study demonstrates that the use of alkyl 3,3,3-trifluoropropanoate, including methyl 3,3,3-trifluoropropanoate (TFPM) and ethyl 3,3,3-trifluoropropanoate (TFPE), as new electrolyte additive can dramatically enhance the high-voltage performance of LiNi 1/3 Co 1/3 Mn 1/3 O 2 /graphite lithium-ion batteries (3.0-4.6 V, vs Li/Li + ). The capacity retention was significantly increased from 45.6% to 75.4% after 100 charge-discharge cycles due to the addition of 0.2 wt % TFPM in the electrolyte, and significantly increased from 45.6% to 76.1% after 100 charge-discharge cycles due to the addition of 0.5 wt % TFPE in the electrolyte, verifying their suitability in this application. Electrochemical impedance spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy were employed to study the effect of TFPM and TFPE on cell performance. The data indicates that the improved cycling activity can be ascribed to the participation of TFPM or TFPE in the formation of a thinner cathode/electrolyte interfacial film, thereby enhancing the cell cycling performance owing to a reduced interfacial resistance at high voltage.

The influence of Lifshitz forces and gas on premelting of ice within porous materials

NASA Astrophysics Data System (ADS)

Boström, M.; Malyi, O. I.; Thiyam, P.; Berland, K.; Brevik, I.; Persson, C.; Parsons, D. F.

2016-07-01

Premelting of ice within pores in earth materials is shown to depend on the presence of vapor layers. For thick vapor layers between ice and pore surfaces, a nanosized water sheet can be formed due to repulsive Lifshitz forces. In the absence of vapor layers, ice is inhibited from melting near pore surfaces. In between these limits, we find an enhancement of the water film thickness in silica and alumina pores. In the presence of metallic surface patches in the pore, the Lifshitz forces can dramatically widen the water film thickness, with potential complete melting of the ice surface.

Bandgap tuning and enhancement of seebeck coefficient in one dimensional GeSe

NASA Astrophysics Data System (ADS)

Kagdada, Hardik L.; Dabhi, Shweta D.; Jha, Prafulla K.

2018-04-01

The first principles based density functional theory is used for tuning the electronic bandgap and thermoelectric properties of bulk, two dimensional (2D) and one dimensional (1D) GeSe. There is an increase in the bandgap going from bulk to 1D with indirect to direct bandgap transition. There is a dramatic change in Seebeck coefficient (S) for GeSe going from bulk to 1D at 300 K. The electrical conductivity and electronic thermal conductivity are lower for 1D GeSe compared to the bulk GeSe due to larger bandgap in the case of 1D GeSe.

Examining Young Children's Perception toward Augmented Reality-Infused Dramatic Play

ERIC Educational Resources Information Center

Han, Jeonghye; Jo, Miheon; Hyun, Eunja; So, Hyo-jeong

2015-01-01

Amid the increasing interest in applying augmented reality (AR) in educational settings, this study explores the design and enactment of an AR-infused robot system to enhance children's satisfaction and sensory engagement with dramatic play activities. In particular, we conducted an exploratory study to empirically examine children's perceptions…

Adaptive Development

NASA Technical Reports Server (NTRS)

2005-01-01

The goal of this research is to develop and demonstrate innovative adaptive seal technologies that can lead to dramatic improvements in engine performance, life, range, and emissions, and enhance operability for next generation gas turbine engines. This work is concentrated on the development of self-adaptive clearance control systems for gas turbine engines. Researchers have targeted the high-pressure turbine (HPT) blade tip seal location for following reasons: Current active clearance control (ACC) systems (e.g., thermal case-cooling schemes) cannot respond to blade tip clearance changes due to mechanical, thermal, and aerodynamic loads. As such they are prone to wear due to the required tight running clearances during operation. Blade tip seal wear (increased clearances) reduces engine efficiency, performance, and service life. Adaptive sealing technology research has inherent impact on all envisioned 21st century propulsion systems (e.g. distributed vectored, hybrid and electric drive propulsion concepts).

Method for enhancing the solubility of dopants in silicon

DOEpatents

Sadigh, Babak; Lenosky, Thomas J.; De La Rubia, Tomas Diaz

2003-09-30

A method for enhancing the equilibrium solid solubility of dopants in silicon, germanium and silicon-germanium alloys. The method involves subjecting silicon-based substrate to biaxial or compression strain. It has been determined that boron solubility was largely enhanced (more than 100%) by a compressive bi-axial strain, based on a size-mismatch theory since the boron atoms are smaller than the silicon atoms. It has been found that the large enhancement or mixing properties of dopants in silicon and germanium substrates is primarily governed by their, and to second order by their size-mismatch with the substrate. Further, it has been determined that the dopant solubility enhancement with strain is most effective when the charge and the size-mismatch of the impurity favor the same type of strain. Thus, the solid solubility of small p-type (e.g., boron) as well as large n-type (e.g., arsenic) dopants can be raised most dramatically by appropriate bi-axial (compressive) strain, and that solubility of a large p-type dopant (e.g, indium) in silicon will be raised due to size-mismatch with silicon, which favors tensile strain, while its negative charge prefers compressive strain, and thus the two effects counteract each other.

Carbon quantum dots coated BiVO{sub 4} inverse opals for enhanced photoelectrochemical hydrogen generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nan, Feng; Shen, Mingrong; Fang, Liang, E-mail: zhkang@suda.edu.cn, E-mail: lfang@suda.edu.cn

Carbon quantum dots (CQDs) coated BiVO{sub 4} inverse opal (io-BiVO{sub 4}) structure that shows dramatic improvement of photoelectrochemical hydrogen generation has been fabricated using electrodeposition with a template. The io-BiVO{sub 4} maximizes photon trapping through slow light effect, while maintaining adequate surface area for effective redox reactions. CQDs are then incorporated to the io-BiVO{sub 4} to further improve the photoconversion efficiency. Due to the strong visible light absorption property of CQDs and enhanced separation of the photoexcited electrons, the CQDs coated io-BiVO{sub 4} exhibit a maximum photo-to-hydrogen conversion efficiency of 0.35%, which is 6 times higher than that of themore » pure BiVO{sub 4} thin films. This work is a good example of designing composite photoelectrode by combining quantum dots and photonic crystal.« less

Odd harmonics-enhanced supercontinuum in bulk solid-state dielectric medium.

PubMed

Garejev, N; Jukna, V; Tamošauskas, G; Veličkė, M; Šuminas, R; Couairon, A; Dubietis, A

2016-07-25

We report on generation of ultrabroadband, more than 4 octave spanning supercontinuum in thin CaF₂ crystal, as pumped by intense mid-infrared laser pulses with central wavelength of 2.4 μm. The supercontinuum spectrum covers wavelength range from the ultraviolet to the mid-infrared and its short wavelength side is strongly enhanced by cascaded generation of third, fifth and seventh harmonics. Our results capture the transition from Kerr-dominated to plasma-dominated filamentation regime and uncover that in the latter the spectral superbroadening originates from dramatic plasma-induced compression of the driving pulse, which in turn induces broadening of the harmonics spectra due to cross-phase modulation effects. The experimental measurements are backed up by the numerical simulations based on a nonparaxial unidirectional propagation equation for the electric field of the pulse, which accounts for the cubic nonlinearity-induced effects, and which reproduce the experimental data in great detail.

Giant photocurrent enhancement by transition metal doping in quantum dot sensitized solar cells

NASA Astrophysics Data System (ADS)

Rimal, Gaurab; Pimachev, Artem K.; Yost, Andrew J.; Poudyal, Uma; Maloney, Scott; Wang, Wenyong; Chien, TeYu; Dahnovsky, Yuri; Tang, Jinke

2016-09-01

A huge enhancement in the incident photon-to-current efficiency of PbS quantum dot (QD) sensitized solar cells by manganese doping is observed. In the presence of Mn dopants with relatively small concentration (4 at. %), the photoelectric current increases by an average of 300% (up to 700%). This effect cannot be explained by the light absorption mechanism because both the experimental and theoretical absorption spectra demonstrate several times decreases in the absorption coefficient. To explain such dramatic increase in the photocurrent we propose the electron tunneling mechanism from the LUMO of the QD excited state to the Zn2SnO4 (ZTO) semiconductor photoanode. This change is due to the presence of the Mn instead of Pb atom at the QD/ZTO interface. The ab initio calculations confirm this mechanism. This work proposes an alternative route for a significant improvement of the efficiency for quantum dot sensitized solar cells.

G-DRG Version 2009: new developments.

PubMed

Müller, Marcel L; Forschner, Andrea; Wenke, Andreas; Luger, Thomas A; Rompel, Rainer; Roeder, Norbert; Hensen, Peter

2009-04-01

The update of the G-DRG system for the year 2009 has been successfully negotiated. Like in the past years, changes are minimal and not dramatic, but they significantly enhance the quality of the DRG system. Once again, the German DRG system demonstrates its versatility and reliability for clinical reimbursement purposes. In the field of dermatology, several improvements or enhancements can be identified; the average case mix index that declined in the past years should now rise by 0.5 percent for 2009. Oncology cases are affected especially by this increase. Some refinements advanced for several years by the German Dermatologic Society (DDG) have been recognized --complex therapies like vacuum wound therapy, isolation due to multi-resistant infections and multiple primary tumors now have better cost weights. Although there still remain some minor problems like reimbursement of cost-intensive treatments, German dermatology is in summary very well prepared for the year 2009.

Au plasmonics in a WS{sub 2}-Au-CuInS{sub 2} photocatalyst for significantly enhanced hydrogen generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Zhongzhou; School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083; Wang, Zhenxing, E-mail: wangzx@nanoctr.cn, E-mail: hej@nanoctr.cn

2015-11-30

Promoting the activities of photocatalysts is still the critical challenge in H{sub 2} generation area. Here, a Au plasmon enhanced photocatalyst of WS{sub 2}-Au-CuInS{sub 2} is developed by inserting Au nanoparticles between WS{sub 2} nanotubes and CuInS{sub 2} (CIS) nanoparticles. Due to the localized surface plasmonic resonance properties from Au nanoparticles, WS{sub 2}-Au-CIS shows the best performance as compared to Au-CIS, CIS, WS{sub 2}-CIS, CIS-Au, WS{sub 2}-Au, and WS{sub 2}-CIS-Au. The surface plasmonic resonance effects dramatically intensify the absorption of visible light and help to inject hot electrons into the semiconductors. Our findings open up an efficient method to optimizemore » the type-II structures for photocatalytic water splitting.« less

Significant improvement in Mn2O3 transition metal oxide electrical conductivity via high pressure

PubMed Central

Hong, Fang; Yue, Binbin; Hirao, Naohisa; Liu, Zhenxian; Chen, Bin

2017-01-01

Highly efficient energy storage is in high demand for next-generation clean energy applications. As a promising energy storage material, the application of Mn2O3 is limited due to its poor electrical conductivity. Here, high-pressure techniques enhanced the electrical conductivity of Mn2O3 significantly. In situ synchrotron micro X-Ray diffraction, Raman spectroscopy and resistivity measurement revealed that resistivity decreased with pressure and dramatically dropped near the phase transition. At the highest pressure, resistivity reduced by five orders of magnitude and the sample showed metal-like behavior. More importantly, resistivity remained much lower than its original value, even when the pressure was fully released. This work provides a new method to enhance the electronic properties of Mn2O3 using high-pressure treatment, benefiting its applications in energy-related fields. PMID:28276479

Enhancing the transmission efficiency by edge deletion in scale-free networks

NASA Astrophysics Data System (ADS)

Zhang, Guo-Qing; Wang, Di; Li, Guo-Jie

2007-07-01

How to improve the transmission efficiency of Internet-like packet switching networks is one of the most important problems in complex networks as well as for the Internet research community. In this paper we propose a convenient method to enhance the transmission efficiency of scale-free networks dramatically by kicking out the edges linking to nodes with large betweenness, which we called the “black sheep.” The advantages of our method are of facility and practical importance. Since the black sheep edges are very costly due to their large bandwidth, our method could decrease the cost as well as gain higher throughput of networks. Moreover, we analyze the curve of the largest betweenness on deleting more and more black sheep edges and find that there is a sharp transition at the critical point where the average degree of the nodes ⟨k⟩→2 .

Photoluminescence-detected magnetic-resonance study of fullerene-doped π-conjugated polymers

NASA Astrophysics Data System (ADS)

Lane, P. A.; Shinar, J.; Yoshino, K.

1996-10-01

X-band photoluminescence (PL)-detected magnetic resonance (PLDMR) spectra of C60- and C70-doped 2,5-dihexoxy poly(p-phenylenevinylene) (DHO-PPV), 2,5-dibutoxy poly(p-phenylene ethynylene) (DBO-PPE), and poly(3-dodecylthiophene) (P3DT) are described and discussed. While light doping of DHO-PPV by both fullerenes quenches the PL, both the polaron and triplet exciton resonances are dramatically enhanced. This is attributed to the creation of conformational defects which enhance the fission of 11Bu singlet excitons to polaron pairs and intersystem crossing to 13Bu triplet excitons. The triplet resonance in all polymers is quenched at relatively low doping levels of C60 and C70, which is attributed to quenching of triplets by positive polarons injected onto the polymer chain. Increased doping by C60, but not C70, quenches the polaron resonance, also due to photoinduced charge transfer.

Effect of enzymatic (thermostable α-amylase) treatment on the physicochemical and antioxidant properties of extruded rice incorporated with soybean flour.

PubMed

Xu, Enbo; Wu, Zhengzong; Pan, Xiaowei; Long, Jie; Wang, Fang; Xu, Xueming; Jin, Zhengyu; Jiao, Aiquan

2016-04-15

In order to determine the effect of enzymatic extrusion on the physicochemical and antioxidant properties of rice/soybean mixture, different mass ratios (100/0, 95/5, 85/15, 70/30, 50/50 and 25/75%, w/w) were treated with thermostable α-amylase. The reduced special mechanical energy and the enhanced product temperature were closely and regularly linked with the increase of soybean content. The bulk density and water solubility index increased, and the water absorption index and viscosities decreased remarkably after enzymatic extrusion, however, the modification caused by α-amylase were dramatically eliminated with the increase of soybean content to ∼50%. Moreover, the addition of enzyme exhibited an improvement of the total phenolic/flavonoid content (TPC/TFC) and antioxidant capacities compared to traditional extrusion. The TPC/TFC retention of extrudate (ratios of 85/15 and 70/30%) attained over 90%, but dramatically decreased (72.91 and 67.81%, respectively) with soybean added to 75%, probably due to the great reduction of starch substrate for enzymatic hydrolysis. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

FIELD DEMONSTRATION STUDIES OF SURFACTANT-ENHANCED SOLUBILIZATION AND MOBILIZATION AT HILL AIR FORCE BASE, UTAH

EPA Science Inventory

Surfactant-enhanced subsurface remediation can dramatically improve contaminant removal rates compared to the traditional pump-and-treat technology. Surfactants can be used to significantly enhance the solubilization of non-aqueous phase liquids (NAPL) constituents, or they can b...

Indentation versus Rolling: Dependence of Adhesion on Contact Geometry for Biomimetic Structures.

PubMed

Moyle, Nichole; He, Zhenping; Wu, Haibin; Hui, Chung-Yuen; Jagota, Anand

2018-04-03

Numerous biomimetic structures made from elastomeric materials have been developed to produce enhancement in properties such as adhesion, static friction, and sliding friction. As a property, one expects adhesion to be represented by an energy per unit area that is usually sensitive to the combination of shear and normal stresses at the crack front but is otherwise dependent only on the two elastic materials that meet at the interface. More specifically, one would expect that adhesion measured by indentation (a popular and convenient technique) could be used to predict adhesion hysteresis in the more practically important rolling geometry. Previously, a structure with a film-terminated fibrillar geometry exhibited dramatic enhancement of adhesion by a crack-trapping mechanism during indentation with a rigid sphere. Roughly isotropic structures such as the fibrillar geometry show a strong correlation between adhesion enhancement in indentation versus adhesion hysteresis in rolling. However, anisotropic structures, such as a film-terminated ridge-channel geometry, surprisingly show a dramatic divergence between adhesion measured by indentation versus rolling. We study this experimentally and theoretically, first comparing the adhesion of the anisotropic ridge-channel structure to the roughly isotropic fibrillar structure during indentation with a rigid sphere, where only the isotropic structure shows adhesion enhancement. Second, we examine in more detail the anomalous anisotropic film-terminated ridge-channel structure during indentation with a rigid sphere versus rolling to show why these structures show a dramatic adhesion enhancement for the rolling case and no adhesion enhancement for indentation.

Terahertz VRT spectroscopy of the water hexamer-d12 prism: Dramatic enhancement of bifurcation tunneling upon librational excitation

NASA Astrophysics Data System (ADS)

Cole, William T. S.; Farrell, James D.; Sheikh, Akber A.; Yönder, Öezlem; Fellers, Raymond S.; Viant, Mark R.; Wales, David J.; Saykally, Richard J.

2018-03-01

Using diode laser vibration-rotation-tunneling spectroscopy near 15 Thz (500 cm-1), we have measured and assigned 142 transitions to three a-type librational subbands of the water hexamer-d12 prism. These subbands reveal dramatically enhanced (ca. 1000×) tunneling splittings relative to the ground state. This enhancement is in agreement with that observed for the water dimer, trimer, and pentamer in this same frequency region. The water prism tunneling motion has been predicted to potentially describe the motions of water in interfacial and confined environments; hence, the results presented here indicate that excitation of librational vibrations has a significant impact on the hydrogen bond dynamics in these macroscopic environments.

Novel ultrasensitive plasmonic detector of terahertz pulses enhanced by femtosecond optical pulses

NASA Astrophysics Data System (ADS)

Shur, M.; Rudin, S.; Rupper, G.; Muraviev, A.

2016-09-01

Plasmonic Field Effect Transistor detectors (first proposed in 1996) have emerged as superior room temperature terahertz (THz) detectors. Recent theoretical and experimental results showed that such detectors are capable of subpicosecond resolution. Their sensitivity can be greatly enhanced by applying the DC drain-to-source current that increases the responsivity due to the enhanced non-linearity of the device but also adds 1/f noise. We now propose, and demonstrate a dramatic responsivity enhancement of these plasmonic THz pulse detectors by applying a femtosecond optical laser pulse superimposed on the THz pulse. The proposed physical mechanism links the enhanced detection to the superposition of the THz pulse field and the rectified optical field. A femtosecond pulse generates a large concentration of the electron-hole pairs shorting the drain and source contacts and, therefore, determining the moment of time when the THz induced charge starts discharging into the transmission line connecting the FET to an oscilloscope. This allows for scanning the THz pulse with the strongly enhanced sensitivity and/or for scanning the response waveform after the THz pulse is over. The experimental results obtained using AlGaAs/InGaAs deep submicron HEMTs are in good agreement with this mechanism. This new technique could find numerous imaging, sensing, and quality control applications.

Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Gunning, Brendan P.; Clinton, Evan A.; Merola, Joseph J.; Doolittle, W. Alan; Bresnahan, Rich C.

2015-10-01

Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N2 while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N2 and 7.7 sccm Ar flows at 600 W radio frequency power, for which the standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 1016 to 3.8 × 1019 cm-3 were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1-2 × 1015 cm-3. The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be addressed. Nonetheless, the dramatically enhanced growth rates demonstrate great promise for the future of III-nitride devices grown by PAMBE.

Cooperative polymerization of α-helices induced by macromolecular architecture

NASA Astrophysics Data System (ADS)

Baumgartner, Ryan; Fu, Hailin; Song, Ziyuan; Lin, Yao; Cheng, Jianjun

2017-07-01

Catalysis observed in enzymatic processes and protein polymerizations often relies on the use of supramolecular interactions and the organization of functional elements in order to gain control over the spatial and temporal elements of fundamental cellular processes. Harnessing these cooperative interactions to catalyse reactions in synthetic systems, however, remains challenging due to the difficulty in creating structurally controlled macromolecules. Here, we report a polypeptide-based macromolecule with spatially organized α-helices that can catalyse its own formation. The system consists of a linear polymeric scaffold containing a high density of initiating groups from which polypeptides are grown, forming a brush polymer. The folding of polypeptide side chains into α-helices dramatically enhances the polymerization rate due to cooperative interactions of macrodipoles between neighbouring α-helices. The parameters that affect the rate are elucidated by a two-stage kinetic model using principles from nucleation-controlled protein polymerizations; the key difference being the irreversible nature of this polymerization.

Refined Estimates of Carbon Abundances for Carbon-Enhanced Metal-Poor Stars

NASA Astrophysics Data System (ADS)

Rossi, S.; Placco, V. M.; Beers, T. C.; Marsteller, B.; Kennedy, C. R.; Sivarani, T.; Masseron, T.; Plez, B.

2008-03-01

We present results from a refined set of procedures for estimation of the metallicities ([Fe/H]) and carbon abundance ratios ([C/Fe]) based on a much larger sample of calibration objects (on the order of 500 stars) then were available to Rossi et al. (2005), due to a dramatic increase in the number of stars with measurements obtained from high-resolution analyses in the past few years. We compare results obtained from a new calibration of the KP and GP indices with that obtained from a custom set of spectral synthesis based on MOOG. In cases where the GP index approaches saturation, it is clear that only spectral synthesis achieve reliable results.

Experimental investigations of timber beams strengthened by CFRP and Rebars under bending

NASA Astrophysics Data System (ADS)

Nianqiang, Zhou; Weixing, Shi

2017-04-01

Wooden structure houses deteriorate over time due to environmental aging, fatigue, and other reasons. In order to solve this problem, composite timber beams strengthened by extra steel bars (rebar) and carbon fiber-reinforced plastic (CFRP) are studied experimentally in this paper. Specimens with various strenghting, ie., rebars only, CFRP only, and a combination of the two, were considered under four-point flexural tests. Failure, displacement and strain response and ductility capacity were evaluated for the present tested models. Dramatic enhancement of the capacity in addition to improved deflection and ductility were gained for the strengthened beams relative to the plain specimens, indicating the effectiveness of the reinforcement on the flexural strength of such composite beams.

The Confluence of Stereotactic Ablative Radiotherapy and Tumor Immunology

PubMed Central

Finkelstein, Steven Eric; Timmerman, Robert; McBride, William H.; Schaue, Dörthe; Hoffe, Sarah E.; Mantz, Constantine A.; Wilson, George D.

2011-01-01

Stereotactic radiation approaches are gaining more popularity for the treatment of intracranial as well as extracranial tumors in organs such as the liver and lung. Technology, rather than biology, is driving the rapid adoption of stereotactic body radiation therapy (SBRT), also known as stereotactic ablative radiotherapy (SABR), in the clinic due to advances in precise positioning and targeting. Dramatic improvements in tumor control have been demonstrated; however, our knowledge of normal tissue biology response mechanisms to large fraction sizes is lacking. Herein, we will discuss how SABR can induce cellular expression of MHC I, adhesion molecules, costimulatory molecules, heat shock proteins, inflammatory mediators, immunomodulatory cytokines, and death receptors to enhance antitumor immune responses. PMID:22162711

CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Vacuum relaxation and annealing-induced enhancement of mobility of regioregular poly (3-hexylthiophene) field-effect transistors

NASA Astrophysics Data System (ADS)

Tian, Xue-Yan; Xu, Zheng; Zhao, Su-Ling; Zhang, Fu-Jun; Xu, Xu-Rong; Yuan, Guang-Cai; Li, Jing; Sun, Qin-Jun; Wang, Ying

2009-11-01

In order to enhance the performance of regioregular poly(3-hexylthiophene) (RR-P3HT) field-effect transistors (FETs), RR-P3HT FETs are prepared by the spin-coating method followed by vacuum placement and annealing. This paper reports that the crystal structure, the molecule interconnection, the surface morphology, and the charge carrier mobility of RR-P3HT films are affected by vacuum relaxation and annealing. The results reveal that the field-effect mobility of RR-P3HT FETs can reach 4.17 × 10-2 m2/(V · s) by vacuum relaxation at room temperature due to an enhanced local self-organization. Furthermore, it reports that an appropriate annealing temperature can facilitate the crystal structure, the orientation and the interconnection of polymer molecules. These results show that the field-effect mobility of device annealed at 150 °C for 10 minutes in vacuum at atmosphere and followed by placement for 20 hours in vacuum at room temperature is enhanced dramatically to 9.00 × 10-2 cm2/(V · s).

Electronic-Reconstruction-Enhanced Tunneling Conductance at Terrace Edges of Ultrathin Oxide Films.

PubMed

Wang, Lingfei; Kim, Rokyeon; Kim, Yoonkoo; Kim, Choong H; Hwang, Sangwoon; Cho, Myung Rae; Shin, Yeong Jae; Das, Saikat; Kim, Jeong Rae; Kalinin, Sergei V; Kim, Miyoung; Yang, Sang Mo; Noh, Tae Won

2017-11-01

Quantum mechanical tunneling of electrons across ultrathin insulating oxide barriers has been studied extensively for decades due to its great potential in electronic-device applications. In the few-nanometers-thick epitaxial oxide films, atomic-scale structural imperfections, such as the ubiquitously existed one-unit-cell-high terrace edges, can dramatically affect the tunneling probability and device performance. However, the underlying physics has not been investigated adequately. Here, taking ultrathin BaTiO 3 films as a model system, an intrinsic tunneling-conductance enhancement is reported near the terrace edges. Scanning-probe-microscopy results demonstrate the existence of highly conductive regions (tens of nanometers wide) near the terrace edges. First-principles calculations suggest that the terrace-edge geometry can trigger an electronic reconstruction, which reduces the effective tunneling barrier width locally. Furthermore, such tunneling-conductance enhancement can be discovered in other transition metal oxides and controlled by surface-termination engineering. The controllable electronic reconstruction can facilitate the implementation of oxide electronic devices and discovery of exotic low-dimensional quantum phases. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhanced Bioavailability and Anticancer Effect of Curcumin-Loaded Electrospun Nanofiber: In Vitro and In Vivo Study

NASA Astrophysics Data System (ADS)

Wang, Chuan; Ma, Chao; Wu, Zhenkai; Liang, He; Yan, Peng; Song, Jia; Ma, Nan; Zhao, Qinghua

2015-11-01

Nanofibers have attracted increasing attention in drug delivery and other biomedical applications due to their some special properties. The present study aims to prepare a fiber-based nanosolid dispersion system to enhance the bioavailability of curcumin (CUR). CUR-loaded polyvinyl pyrrolidone (CUR@PVP) nanofibers were successfully prepared via electrospinning. Scanning electron microscopy (SEM) was employed to observe the morphology of the nanofibers, and the SEM image showed that the drug-loaded nanofibers were smooth, and no CUR clusters were found on the surface of the nanofibers. The results of X-ray diffraction (XRD) demonstrated that the CUR was evenly distributed in the nanofibers in an amorphous state. Fourier transform infrared (FTIR) spectroscopy analysis indicated that intermolecular hydrogen bonding occurred between the CUR and the polymer matrix. In vitro dissolution profiles showed that CUR@PVP nanofiber could be quickly dissolved in phosphate-buffered saline (PBS) solution, while negligible dissolution was observed in pure CUR sample. Importantly, in vitro cell viability assays and in vivo animal tests revealed that the nanosolid dispersion system dramatically enhanced the bioavailability and showed effective anticancer effect of the CUR.

Re-engineering Cytochrome P450 2B11dH for Enhanced Metabolism of Several Substrates Including the Anti-cancer Prodrugs Cyclophosphamide and Ifosfamide

PubMed Central

Sun, Ling; Chen, Chong S.; Waxman, David J.; Liu, Hong; Halpert, James R.; Kumar, Santosh

2007-01-01

Based on recent directed evolution of P450 2B1, six P450 2B11 mutants at three positions were created in an N-terminal modified construct termed P450 2B11dH and characterized for enzyme catalysis using five substrates. Mutant I209A demonstrated a 3.2-fold enhanced kcat/Km for 7-ethoxy-4-trifluoromethylcourmarin O-deethylation, largely due to a dramatic decrease in Km (0.72 vs. 18 μM). I209A also demonstrated enhanced selectivity for testosterone 16β-hydroxylation over 16α-hydroxylation. In contrast, V183L showed a 4-fold increased kcat for 7-benzyloxyresorufin debenzylation and a 4.7-fold increased kcat/Km for testosterone 16α-hydroxylation. V183L also displayed a 1.7-fold higher kcat/Km than P450 2B11dH with the anti-cancer prodrugs cyclophosphamide and ifosfamide, resulting from a ~4-fold decrease in Km. Introduction of the V183L mutation into full-length P450 2B11 did not enhance the kcat/Km. Overall, the re-engineered P450 2B11dH enzymes exhibited enhanced catalytic efficiency with several substrates including the anti-cancer prodrugs. PMID:17254539

Plum Fruit Development Occurs via Gibberellin–Sensitive and –Insensitive DELLA Repressors

PubMed Central

El-Sharkawy, Islam; Sherif, Sherif; Abdulla, Mahboob

2017-01-01

Fruit growth depends on highly coordinated hormonal activities. The phytohormone gibberellin (GA) promotes growth by triggering degradation of the growth-repressing DELLA proteins; however, the extent to which such proteins contribute to GA-mediated fruit development remains to be clarified. Three new plum genes encoding DELLA proteins, PslGAI, PslRGL and PslRGA were isolated and functionally characterized. Analysis of expression profile during fruit development suggested that PslDELLA are transcriptionally regulated during flower and fruit ontogeny with potential positive regulation by GA and ethylene, depending on organ and developmental stage. PslGAI and PslRGL deduced proteins contain all domains present in typical DELLA proteins. However, PslRGA exhibited a degenerated DELLA domain and subsequently lacks in GID1–DELLA interaction property. PslDELLA–overexpression in WT Arabidopsis caused dramatic disruption in overall growth including root length, stem elongation, plant architecture, flower structure, fertility, and considerable retardation in development due to dramatic distortion in GA-metabolic pathway. GA treatment enhanced PslGAI/PslRGL interaction with PslGID1 receptors, causing protein destabilization and relief of growth-restraining effect. By contrast, PslRGA protein was not degraded by GA due to its inability to interact with PslGID1. Relative to other PslDELLA–mutants, PslRGA–plants displayed stronger constitutive repressive growth that was irreversible by GA application. The present results describe additional complexities in GA-signalling during plum fruit development, which may be particularly important to optimize successful reproductive growth. PMID:28076366

Efficient Direct Lineage Reprogramming of Fibroblasts into Induced Cardiomyocytes Using Nanotopographical Cues.

PubMed

Yoo, Junsang; Chang, Yujung; Kim, Hongwon; Baek, Soonbong; Choi, Hwan; Jeong, Gun-Jae; Shin, Jaein; Kim, Hongnam; Kim, Byung-Soo; Kim, Jongpil

2017-03-01

Induced cardiomyocytes (iCMs) generated via direct lineage reprogramming offer a novel therapeutic target for the study and treatment of cardiac diseases. However, the efficiency of iCM generation is significantly low for therapeutic applications. Here, we show an efficient direct conversion of somatic fibroblasts into iCMs using nanotopographic cues. Compared with flat substrates, the direct conversion of fibroblasts into iCMs on nanopatterned substrates resulted in a dramatic increase in the reprogramming efficiency and maturation of iCM phenotypes. Additionally, enhanced reprogramming by substrate nanotopography was due to changes in the activation of focal adhesion kinase and specific histone modifications. Taken together, these results suggest that nanotopographic cues can serve as an efficient stimulant for direct lineage reprogramming into iCMs.

Properties of PMR Polyimides Improved by Preparation of Polyhedral Oligomeric Silsesquioxane (POSS) Nanocomposites

NASA Technical Reports Server (NTRS)

Campbell, Sandi G.; Lee, Andre

2005-01-01

The field of hybrid organic-inorganic materials has grown drastically over the last several years. This interest stems from our ever-increasing ability to custom-build and control molecular structure at several length scales. This ability to control both the composition and structure of hybrid materials is sometimes broadly referred to as nanocomposite systems. One class of hybrid (organic-inorganic) nanostructured material is polyhedral oligomeric silsesquioxane (POSS), shown in the preceding diagram. The hybrid composition gives POSS materials dramatically enhanced properties relative to traditional hydrocarbons and inorganics. An important benefit of this technology is that it makes possible the formulations of nanostructured chemicals with excellent thermal and oxidative stability. This is largely due to the inorganic component.

High performance liquid chromatography column efficiency enhancement by zero dead volume recycling and practical approach using park and recycle arrangement.

PubMed

Minarik, Marek; Franc, Martin; Minarik, Milan

2018-06-15

A new instrumental approach to recycling HPLC is described. The concept is based on fast reintroduction of incremental peak sections back onto the separation column. The re-circulation is performed within a closed loop containing only the column and two synchronized switching valves. By having HPLC pump out of the cycle, the method minimizes peak broadening due to dead volume. As a result the efficiency is dramatically increased allowing for the most demanding analytical applications. In addition, a parking loop is employed for temporary storage of analytes from the middle section of the separated mixture prior to their recycling. Copyright © 2018 Elsevier B.V. All rights reserved.

Mammalian phospholipase D: activation by ammonium sulfate and nucleotides.

PubMed Central

Nakamura, S; Shimooku, K; Akisue, T; Jinnai, H; Hitomi, T; Kiyohara, Y; Ogino, C; Yoshida, K; Nishizuka, Y

1995-01-01

Phospholipase D (PLD) associated with the rat kidney membrane was activated by guanine 5'-[gamma-thio]triphosphate and a cytosol fraction that contained ADP-ribosylation factor. When assayed by measuring the phosphatidyl transfer reaction to ethanol with exogenously added radioactive phosphatidylcholine as substrate, the PLD required a high concentration (1.6 M) of ammonium sulfate to exhibit high enzymatic activity. Other salts examined were far less effective or practically inactive, and this dramatic action of ammonium sulfate is not simply due to such high ionic strength. Addition of ATP but not of nonhydrolyzable ATP analogue adenosine 5'-[beta, gamma-imido]diphosphate further enhanced the PLD activation approximately equal to 2- to 3-fold. This enhancement by ATP needed cytosol, implying a role of protein phosphorylation. A survey of PLD activity in rat tissues revealed that, unlike in previous observations reported thus far, PLD was most abundant in membrane fractions of kidney, spleen, and liver in this order, and the enzymatic activity in brain and lung was low. PMID:8618893

The Exposure Advantage: Early Exposure to a Multilingual Environment Promotes Effective Communication.

PubMed

Fan, Samantha P; Liberman, Zoe; Keysar, Boaz; Kinzler, Katherine D

2015-07-01

Early language exposure is essential to developing a formal language system, but may not be sufficient for communicating effectively. To understand a speaker's intention, one must take the speaker's perspective. Multilingual exposure may promote effective communication by enhancing perspective taking. We tested children on a task that required perspective taking to interpret a speaker's intended meaning. Monolingual children failed to interpret the speaker's meaning dramatically more often than both bilingual children and children who were exposed to a multilingual environment but were not bilingual themselves. Children who were merely exposed to a second language performed as well as bilingual children, despite having lower executive-function scores. Thus, the communicative advantages demonstrated by the bilinguals may be social in origin, and not due to enhanced executive control. For millennia, multilingual exposure has been the norm. Our study shows that such an environment may facilitate the development of perspective-taking tools that are critical for effective communication. © The Author(s) 2015.

Enhancement mechanisms of short-time aerobic digestion for waste activated sludge in the presence of cocoamidopropyl betaine.

PubMed

Xia, Siqing; Zhou, Yun; Eustance, Everett; Zhang, Zhiqiang

2017-10-18

Cocoamidopropyl betaine (CAPB), which is a biodegradable ampholytic surfactant, has recently been found to dramatically enhance the aerobic digestion of waste activated sludge (WAS) in short-time aerobic digestion (STAD) systems. Therefore, it is important to understand the mechanisms in which CAPB enhances WAS aerobic digestion performance. Results showed that CAPB could dramatically enhance the solubilization of soluble proteins (PN), polysaccharides (PS), nucleic acids (NA) and humic-like substances (HS) in the STAD system within the initial 2 h. Then PN, PS and NA gradually decreased, while HS showed only minor decease. In addition, CAPB increased the proportion of low MW fractions (<20 kDa) from 4.22% to 39.4%, which are more biodegradable. Specific oxygen uptake rates and dehydrogenase enzyme activity results indicated that CAPB markedly improved the aerobic microorganism activities. Microbial community analyses and principle coordinate analyses (PCoA) revealed that CAPB increased the proportion of some functional microorganisms, including Proteobacteria, Planctomycetales, Acinetobacter, Pseudomonas and Aeromonas. The changes driven by CAPB could explain the enhanced performance of the STAD system for WAS aerobic treatment.

Pension Enhancements and the Retention of Public Employees: Evidence from Teaching. Working Paper 123

ERIC Educational Resources Information Center

Koedel, Cory; Xiang, P. Brett

2015-01-01

We use data from workers in the largest public-sector occupation in the United States -- teaching -- to examine the effect of pension enhancements on employee retention. Specifically, we study a 1999 enhancement to the benefit formula for public school teachers in St. Louis that resulted in an immediate and dramatic increase in their incentives to…

Self-accelerated development of salt karst during flash floods along the Dead Sea Coast, Israel

NASA Astrophysics Data System (ADS)

Avni, Yoav; Lensky, Nadav; Dente, Elad; Shviro, Maayan; Arav, Reuma; Gavrieli, Ittai; Yechieli, Yoseph; Abelson, Meir; Lutzky, Hallel; Filin, Sagi; Haviv, Itai; Baer, Gidon

2016-01-01

We document and analyze the rapid development of a real-time karst system within the subsurface salt layers of the Ze'elim Fan, Dead Sea, Israel by a multidisciplinary study that combines interferometric synthetic aperture radar and light detection and ranging measurements, sinkhole mapping, time-lapse camera monitoring, groundwater level measurements and chemical and isotopic analyses of surface runoff and groundwater. The >1 m/yr drop of Dead Sea water level and the subsequent change in the adjacent groundwater system since the 1960s resulted in flushing of the coastal aquifer by fresh groundwater, subsurface salt dissolution, gradual land subsidence and formation of sinkholes. Since 2010 this process accelerated dramatically as flash floods at the Ze'elim Fan were drained by newly formed sinkholes. During and immediately after these flood events the dissolution rates of the subsurface salt layer increased dramatically, the overlying ground surface subsided, a large number of sinkholes developed over short time periods (hours to days), and salt-saturated water resurged downstream. Groundwater flow velocities increased by more than 2 orders of magnitudes compared to previously measured velocities along the Dead Sea. The process is self-accelerating as salt dissolution enhances subsidence and sinkhole formation, which in turn increase the ponding areas of flood water and generate additional draining conduits to the subsurface. The rapid terrain response is predominantly due to the highly soluble salt. It is enhanced by the shallow depth of the salt layer, the low competence of the newly exposed unconsolidated overburden and the moderate topographic gradients of the Ze'elim Fan.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Dustin; Zhao, Fangchao; Tong, Kwing

Here, the extended lifetime of organic light-emitting diodes (OLEDs) based on enhanced electrical stability of a silver nanowire (AgNW) transparent conductive electrode is reported. Specifically, in depth investigation is performed on the ability of atomic layer deposition deposited zinc oxide (ZnO) on AgNWs to render the nanowires electrically stable during electrical stressing at the range of operational current density used for OLED lighting. ZnO-coated AgNWs have been observed to show no electrical, optical, or morphological degradation, while pristine AgNW electrodes have become unusable for optoelectronic devices due to dramatic decreases in conductivity, transparency, and fragmentation of the nanowire network atmore » ≈150 mA cm -2. When fabricated into OLED substrates, resulting OLEDs fabricated on the ZnO-AgNW platform exhibit a 140% increase in lifetime when compared to OLEDs fabricated on indium tin oxide (ITO)/glass, and ≈20% when compared to OLEDs fabricated on AgNW based substrates. While both ZnO-coated and pristine AgNW substrates outperform ITO/glass due to the lower current densities required to drive the device, morphological stability in response to current stressing is responsible for the enhancement of lifetime of ZnO-AgNW based OLEDs compared to pristine AgNW based OLEDs.« less

The effect of nutrient enrichment on growth, photosynthesis and hydraulic conductance of dwarf mangroves in Panamá

USGS Publications Warehouse

Lovelock, C.E.; Feller, Ilka C.; McKee, K.L.; Engelbrecht, B.M.J.; Ball, M.C.

2004-01-01

1. Dwarf stands of the mangrove Rhizophora mangle L. are extensive in the Caribbean. We fertilized dwarf trees in Almirante Bay, Bocas del Toro Province, north-eastern Panama with nitrogen (N) and phosphorus (P) to determine (1) if growth limitations are due to nutrient deficiency; and (2) what morphological and/or physiological factors underlie nutrient limitations to growth. 2. Shoot growth was 10-fold when fertilized with P and twofold with N fertilization, indicating that stunted growth of these mangroves is partially due to nutrient deficiency. 3. Growth enhancements caused by N or P enrichment could not be attributed to increases in photosynthesis on a leaf area basis, although photosynthetic nutrient-use efficiency was improved. The most dramatic effect was on stem hydraulic conductance, which was increased sixfold by P and 2-5-fold with N enrichment. Fertilization with P enhanced leaf and stem P concentrations and reduced C:N ratio, but did not alter leaf damage by herbivores. 4. Our findings indicate that addition of N and P significantly alter tree growth and internal nutrient dynamics of mangroves at Bocas del Toro, but also that the magnitude, pattern and mechanisms of change will be differentially affected by each nutrient.

Younger Dryas cooling and the Greenland climate response to CO2.

PubMed

Liu, Zhengyu; Carlson, Anders E; He, Feng; Brady, Esther C; Otto-Bliesner, Bette L; Briegleb, Bruce P; Wehrenberg, Mark; Clark, Peter U; Wu, Shu; Cheng, Jun; Zhang, Jiaxu; Noone, David; Zhu, Jiang

2012-07-10

Greenland ice-core δ(18)O-temperature reconstructions suggest a dramatic cooling during the Younger Dryas (YD; 12.9-11.7 ka), with temperatures being as cold as the earlier Oldest Dryas (OD; 18.0-14.6 ka) despite an approximately 50 ppm rise in atmospheric CO(2). Such YD cooling implies a muted Greenland climate response to atmospheric CO(2), contrary to physical predictions of an enhanced high-latitude response to future increases in CO(2). Here we show that North Atlantic sea surface temperature reconstructions as well as transient climate model simulations suggest that the YD over Greenland should be substantially warmer than the OD by approximately 5 °C in response to increased atmospheric CO(2). Additional experiments with an isotope-enabled model suggest that the apparent YD temperature reconstruction derived from the ice-core δ(18)O record is likely an artifact of an altered temperature-δ(18)O relationship due to changing deglacial atmospheric circulation. Our results thus suggest that Greenland climate was warmer during the YD relative to the OD in response to rising atmospheric CO(2), consistent with sea surface temperature reconstructions and physical predictions, and has a sensitivity approximately twice that found in climate models for current climate due to an enhanced albedo feedback during the last deglaciation.

Modular Chemical Process Intensification: A Review.

PubMed

Kim, Yong-Ha; Park, Lydia K; Yiacoumi, Sotira; Tsouris, Costas

2017-06-07

Modular chemical process intensification can dramatically improve energy and process efficiencies of chemical processes through enhanced mass and heat transfer, application of external force fields, enhanced driving forces, and combinations of different unit operations, such as reaction and separation, in single-process equipment. These dramatic improvements lead to several benefits such as compactness or small footprint, energy and cost savings, enhanced safety, less waste production, and higher product quality. Because of these benefits, process intensification can play a major role in industrial and manufacturing sectors, including chemical, pulp and paper, energy, critical materials, and water treatment, among others. This article provides an overview of process intensification, including definitions, principles, tools, and possible applications, with the objective to contribute to the future development and potential applications of modular chemical process intensification in industrial and manufacturing sectors. Drivers and barriers contributing to the advancement of process intensification technologies are discussed.

Modular Chemical Process Intensification: A Review

DOE PAGES

Kim, Yong-ha; Park, Lydia K.; Yiacoumi, Sotira; ...

2016-06-24

Modular chemical process intensification can dramatically improve energy and process efficiencies of chemical processes through enhanced mass and heat transfer, application of external force fields, enhanced driving forces, and combinations of different unit operations, such as reaction and separation, in single-process equipment. Dramatic improvements such as these lead to several benefits such as compactness or small footprint, energy and cost savings, enhanced safety, less waste production, and higher product quality. Because of these benefits, process intensification can play a major role in industrial and manufacturing sectors, including chemical, pulp and paper, energy, critical materials, and water treatment, among others. Thismore » article provides an overview of process intensification, including definitions, principles, tools, and possible applications, with the objective to contribute to the future development and potential applications of modular chemical process intensification in industrial and manufacturing sectors. Drivers and barriers contributing to the advancement of process intensification technologies are discussed.« less

Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gunning, Brendan P.; Clinton, Evan A.; Merola, Joseph J.

2015-10-21

Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N{sub 2} while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N{sub 2} and 7.7 sccm Ar flows at 600 W radio frequency power, for which themore » standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 10{sup 16} to 3.8 × 10{sup 19} cm{sup −3} were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1–2 × 10{sup 15} cm{sup −3}. The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be addressed. Nonetheless, the dramatically enhanced growth rates demonstrate great promise for the future of III-nitride devices grown by PAMBE.« less

Do enhanced states exist? Boosting cognitive capacities through an action video-game.

PubMed

Kozhevnikov, Maria; Li, Yahui; Wong, Sabrina; Obana, Takashi; Amihai, Ido

2018-04-01

This research reports the existence of enhanced cognitive states in which dramatic temporary improvements in temporal and spatial aspects of attention were exhibited by participants who played (but not by those who merely observed) action video-games meeting certain criteria. Specifically, Experiments 1 and 2 demonstrate that the attentional improvements were exhibited only by participants whose skills matched the difficulty level of the video game. Experiment 2 showed that arousal (as reflected by the reduction in parasympathetic activity and increase in sympathetic activity) is a critical physiological condition for enhanced cognitive states and corresponding attentional enhancements. Experiment 3 showed that the cognitive enhancements were transient, and were no longer observed after 30 min of rest following video-gaming. Moreover, the results suggest that the enhancements were specific to tasks requiring visual-spatial focused attention, but not distribution of spatial attention as has been reported to improve significantly and durably as a result of long-term video-game playing. Overall, the results suggest that the observed enhancements cannot be simply due to the activity of video-gaming per se, but might rather represent an enhanced cognitive state resulting from specific conditions (heightened arousal in combination with active engagement and optimal challenge), resonant with what has been described in previous phenomenological literature as "flow" (Csikszentmihalyi, 1975) or "peak experiences" (Maslov, 1962). The findings provide empirical evidence for the existence of the enhanced cognitive states and suggest possibilities for consciously accessing latent resources of our brain to temporarily boost our cognitive capacities upon demand. Copyright © 2018 Elsevier B.V. All rights reserved.

A long-lived refilling event of the slot region between the Van Allen radiation belts from Nov 2004 to Jan 2005

NASA Astrophysics Data System (ADS)

Yang, X.

2015-12-01

A powerful relativistic electron enhancement in the slot region between the inner and outer radiation belts is investigated by multi-satellites measurements. The measurement from Space Particle Component Detectors (SPCDs) aboard Fengyun-1 indicates that the relativistic electron (>1.6MeV) flux began to enhance obviously on early 10 November with the flux peak fixed at L~3.0. In the next day, the relativistic electron populations increased dramatically. Subsequently, the flux had been enhancing slowly, but unceasingly, until 17 November, and the maximum flux reached up to 7.8×104 cm-2·sr-1·s-1 at last. The flux peak fixed at L~3.0 and the very slow decay rate in this event make it to be an unusual long-lived slot region refilling event. We trace the cause of the event back to the interplanetary environment and find that there were two evident magnetic cloud constructions: dramatically enhanced magnetic field strength and long and smooth rotation of field vector from late 7 to 8 November and from late 9 to 10 November, respectively; solar wind speed increased in 'step-like' fashion on late 7 November and persisted the level of high speed >560 km·s-1 for about 124 hours. Owed to the interplanetary disturbances, very strong magnetic storms and substorms occurred in the magnetosphere. Responding to the extraordinarily magnetic perturbations, the plasmasphere shrank sharply. The location of plasmapause inferred from Dst indicates that the plasmapause shrank inward to as low as L~2.5. On account of these magnetospheric conditions, strong chorus emissions are expected near the earth. In fact, the STAFF on Cluster mission measured intensive whistler mode chorus emissions on 10 and 12 November, corresponding to the period of the remarkable enhancement of relativistic electron. Furthermore, we investigate the radial profile of phase space density (PSD) by electron flux from multi-satellites, and the evolution of the phase space density profile reveals that the local acceleration by whistler mode chorus could be the important mechanism in this event. The movement of the inferred plasmapause location indicates that the enhanced outer zone is divided into two portions by the plasmapause and the slow loss rate in the plasmasphere due to hiss primarily contributed to the long-lived characteristic of this event.

Efficient Suppression of Electron–Hole Recombination in Oxygen-Deficient Hydrogen-Treated TiO2 Nanowires for Photoelectrochemical Water Splitting

PubMed Central

2013-01-01

There is an increasing level of interest in the use of black TiO2 prepared by thermal hydrogen treatments (H:TiO2) due to the potential to enhance both the photocatalytic and the light-harvesting properties of TiO2. Here, we examine oxygen-deficient H:TiO2 nanotube arrays that have previously achieved very high solar-to-hydrogen (STH) efficiencies due to incident photon-to-current efficiency (IPCE) values of >90% for photoelectrochemical water splitting at only 0.4 V vs RHE under UV illumination. Our transient absorption (TA) mechanistic study provides strong evidence that the improved electrical properties of oxygen-deficient TiO2 enables remarkably efficient spatial separation of electron–hole pairs on the submicrosecond time scale at moderate applied bias, and this coupled to effective suppression of microsecond to seconds charge carrier recombination is the primary factor behind the dramatically improved photoelectrochemical activity. PMID:24376902

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rout, Dipak; Vijaya, R.; Centre for Lasers and Photonics, Indian Institute of Technology Kanpur, Kanpur 208016

Well-ordered opaline photonic crystals are grown by inward growing self-assembly method from Rhodamine B dye-doped polystyrene colloids. Subsequent to self-assembly, the crystals are infiltrated with gold nanoparticles of 40 nm diameter. Measurements of the stopband features and photoluminescence intensity from these crystals are supplemented by fluorescence decay time analysis. The fluorescence decay times from the dye-doped photonic crystals before and after the infiltration are dramatically different from each other. A lowered fluorescence decay time was observed for the case of gold infiltrated crystal along with an enhanced emission intensity. Double-exponential decay nature of the fluorescence from the dye-doped crystal gets convertedmore » into single-exponential decay upon the infiltration of gold nanoparticles due to the resonant radiative process resulting from the overlap of the surface plasmon resonance with the emission spectrum. The influence of localized surface plasmon due to gold nanoparticles on the increase in emission intensity and decrease in decay time of the emitters is established.« less

Carbon dot/polyvinylpyrrolidone hybrid nanofibers with efficient solid-state photoluminescence constructed using an electrospinning technique

NASA Astrophysics Data System (ADS)

Zhai, Yue; Bai, Xue; Cui, Haining; Zhu, Jinyang; Liu, Wei; Zhang, Tianxiang; Dong, Biao; Pan, Gencai; Xu, Lin; Zhang, Shuang; Song, Hongwei

2018-01-01

Carbon dots (CDs) are the promising candidates for application in optoelectronic and biological areas due to their excellent photostability, unique photoluminescence, good biocompatibility, low toxicity and chemical inertness. However, the self-quenching of photoluminescence as they are dried into the solid state dramatically limits their further application. Therefore, realizing efficient photoluminescence and large-scale production of CDs in the solid state is an urgent challenge. Herein, solid-state hybrid nanofibers based on CDs and polyvinylpyrrolidone (PVP) are constructed through an electrospinning process. The resulting solid-state hybrid PVP/CD nanofibers present much enhanced photoluminescence performance compared to the corresponding pristine colloidal CDs due to the decrease in non-radiative recombination of electron-holes. Owing to the suppressed self-quenching of CDs, the photoluminescence quantum yield is considerably improved from 42.9% of pristine CDs to 83.5% of nanofibers under the excitation wavelength of 360 nm. This has great application potential in optical or optoelectronic devices.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Siwei; Chen, Yan; Zhang, Lingling

Ceramic-based proton conductors enable high-temperature hydrogen economy applications such as hydrogen separation membranes, fuel cells, and steam electrolyzers. BaZr 0.8Y 0.2O 3-δ(BZY) proton-conducting oxide possesses the highest level of proton conductivity reported to date, but poor sinterability hinders its widespread utilization. In this paper, we report a two-step reactive aid sintering (TRAS) method involving the introduction of BaCO 3 and B 2O 3-Li 2O for the preparation of dense BZY ceramics sintered at 1500°C. The resulting BZY samples showed a pure perovskite structure with a dramatic increase in the relative density to 91.5%. In addition, the shrinkage during sintering wasmore » improved to 19.3% by a TRAS method as compared to 2.6% by the conventional solid date reaction method. In conclusion, the bulk conductivity was improved due to enhanced densification, while the grain boundary conductivity decreased due to the blocking behavior of the sintering aid resulting in a decrease in the total conductivity of the samples.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Siwei; Chen, Yan; Zhang, Lingling

Ceramic-based proton conductors enable high-temperature hydrogen economy applications such as hydrogen separation membranes, fuel cells, and steam electrolyzers. BaZr 0.8Y 0.2O 3-δ (BZY) proton-conducting oxide possesses the highest level of proton conductivity reported to date, but poor sinterability hinders its widespread utilization. Here, we report a two-step reactive aid sintering (TRAS) method involving the introduction of BaCO 3 and B 2O 3-Li 2O for the preparation of dense BZY ceramics sintered at 1500°C. The resulting BZY samples showed a pure perovskite structure with a dramatic increase in the relative density to 91.5%. In addition, the shrinkage during sintering was improvedmore » to 19.3% by a TRAS method as compared to 2.6% by the conventional solid date reaction method. Moreover, the bulk conductivity was improved due to enhanced densification, while the grain boundary conductivity decreased due to the blocking behavior of the sintering aid resulting in a decrease in the total conductivity of the samples.« less

Photovoltaic-Pyroelectric Coupled Effect Induced Electricity for Self-Powered Photodetector System.

PubMed

Ma, Nan; Zhang, Kewei; Yang, Ya

2017-12-01

Ferroelectric materials have demonstrated novel photovoltaic effect to scavenge solar energy. However, most of the ferroelectric materials with wide bandgaps (2.7-4 eV) suffer from low power conversion efficiency of less than 0.5% due to absorbing only 8-20% of solar spectrum. Instead of harvesting solar energy, these ferroelectric materials can be well suited for photodetector applications, especially for sensing near-UV irradiations. Here, a ferroelectric BaTiO 3 film-based photodetector is demonstrated that can be operated without using any external power source and a fast sensing of 405 nm light illumination is enabled. As compared with photovoltaic effect, both the responsivity and the specific detectivity of the photodetector can be dramatically enhanced by larger than 260% due to the light-induced photovoltaic-pyroelectric coupled effect. A self-powered photodetector array system can be utilized to achieve spatially resolved light intensity detection by recording the output voltage signals as a mapping figure. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Characterizing Spatial and Temporal Patterns of Thermal Environment and Air Quality in Taipei Metropolitan Area

NASA Astrophysics Data System (ADS)

Juang, J. Y.; Sun, C. H.; Jiang, J. A.; Wen, T. H.

2017-12-01

The urban heat island effect (UHI) caused by the regional-to-global environmental changes, dramatic urbanization, and shifting in land-use compositions has becoming an important environmental issue in recent years. In the past century, the coverage of urban area in Taipei Basin has dramatically increasing by ten folds. The strengthen of UHI effect significantly enhances the frequency of warm-night effect, and strongly influences the thermal environment of the residents in the Greater Taipei Metropolitan. In addition, the urban expansions due to dramatic increasing in urban populations and traffic loading significantly impacts the air quality and causes health issue in Taipei. In this study, the main objective is to quantify and characterize the temporal and spatial distributions of thermal environmental and air quality in the Greater Taipei Metropolitan Area by using monitoring data from Central Weather Bureau, Environmental Protection Administration. In addition, in this study, we conduct the analysis on the distribution of physiological equivalent temperature in the micro scale in the metropolitan area by using the observation data and quantitative simulation to investigate how the thermal environment is influenced under different conditions. Furthermore, we establish a real-time mobile monitoring system by using wireless sensor network to investigate the correlation between the thermal environment, air quality and other environmental factors, and propose to develop the early warning system for heat stress and air quality in the metropolitan area. The results from this study can be integrated into the management and planning system, and provide sufficient and important background information for the development of smart city in the metropolitan area in the future.

Long-Term Priming by Three Small Molecules Is a Promising Strategy for Enhancing Late Endothelial Progenitor Cell Bioactivities.

PubMed

Kim, Yeon-Ju; Ji, Seung Taek; Kim, Da Yeon; Jung, Seok Yun; Kang, Songhwa; Park, Ji Hye; Jang, Woong Bi; Yun, Jisoo; Ha, Jongseong; Lee, Dong Hyung; Kwon, Sang-Mo

2018-06-12

Endothelial progenitor cells (EPCs) and outgrowth endothelial cells (OECs) play a pivotal role in vascular regeneration in ischemic tissues; however, their therapeutic application in clinical settings is limited due to the low quality and quantity of patient-derived circulating EPCs. To solve this problem, we evaluated whether three priming small molecules (tauroursodeoxycholic acid, fucoidan, oleuropein) could enhance the angiogenic potential of EPCs. Such enhancement would promote the cellular bioactivities and help to develop functionally improved EPC therapeutics for ischemic diseases by accelerating the priming effect of the defined physiological molecules. We found that preconditioning of each of the three small molecules significantly induced the differentiation potential of CD34+ stem cells into EPC lineage cells. Notably, long-term priming of OECs with the three chemical cocktail (OEC-3C) increased the proliferation potential of EPCs via ERK activation. The migration, invasion, and tube-forming capacities were also significantly enhanced in OEC-3Cs compared with unprimed OECs. Further, the cell survival ratio was dramatically increased in OEC-3Cs against H2O2-induced oxidative stress via the augmented expression of Bcl-2, a prosurvival protein. In conclusion, we identified three small molecules for enhancing the bioactivities of ex vivo-expanded OECs for vascular repair. Long-term 3C priming might be a promising methodology for EPC-based therapy against ischemic diseases.

Lysine Decarboxylase with an Enhanced Affinity for Pyridoxal 5-Phosphate by Disulfide Bond-Mediated Spatial Reconstitution.

PubMed

Sagong, Hye-Young; Kim, Kyung-Jin

2017-01-01

Lysine decarboxylase (LDC) catalyzes the decarboxylation of l-lysine to produce cadaverine, an important industrial platform chemical for bio-based polyamides. However, due to high flexibility at the pyridoxal 5-phosphate (PLP) binding site, use of the enzyme for cadaverine production requires continuous supplement of large amounts of PLP. In order to develop an LDC enzyme from Selenomonas ruminantium (SrLDC) with an enhanced affinity for PLP, we introduced an internal disulfide bond between Ala225 and Thr302 residues with a desire to retain the PLP binding site in a closed conformation. The SrLDCA225C/T302C mutant showed a yellow color and the characteristic UV/Vis absorption peaks for enzymes with bound PLP, and exhibited three-fold enhanced PLP affinity compared with the wild-type SrLDC. The mutant also exhibited a dramatically enhanced LDC activity and cadaverine conversion particularly under no or low PLP concentrations. Moreover, introduction of the disulfide bond rendered SrLDC more resistant to high pH and temperature. The formation of the introduced disulfide bond and the maintenance of the PLP binding site in the closed conformation were confirmed by determination of the crystal structure of the mutant. This study shows that disulfide bond-mediated spatial reconstitution can be a platform technology for development of enzymes with enhanced PLP affinity.

Measurement of absorption spectrum of deuterium oxide (D{sub 2}O) and its application to signal enhancement in multiphoton microscopy at the 1700-nm window

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yuxin; Wen, Wenhui; Wang, Kai

2016-01-11

1700-nm window has been demonstrated to be a promising excitation window for deep-tissue multiphoton microscopy (MPM). Long working-distance water immersion objective lenses are typically used for deep-tissue imaging. However, absorption due to immersion water at 1700 nm is still high and leads to dramatic decrease in signals. In this paper, we demonstrate measurement of absorption spectrum of deuterium oxide (D{sub 2}O) from 1200 nm to 2600 nm, covering the three low water-absorption windows potentially applicable for deep-tissue imaging (1300 nm, 1700 nm, and 2200 nm). We apply this measured result to signal enhancement in MPM at the 1700-nm window. Compared with water immersion, D{sub 2}O immersionmore » enhances signal levels in second-harmonic generation imaging, 3-photon fluorescence imaging, and third-harmonic generation imaging by 8.1, 24.8, and 24.7 times with 1662-nm excitation, in good agreement with theoretical calculation based on our absorption measurement. This suggests D{sub 2}O a promising immersion medium for deep-tissue imaging.« less

Enhanced solubility and antioxidant activity of chlorogenic acid-chitosan conjugates due to the conjugation of chitosan with chlorogenic acid.

PubMed

Rui, Liyun; Xie, Minhao; Hu, Bing; Zhou, Li; Saeeduddin, Muhammad; Zeng, Xiaoxiong

2017-08-15

Chlorogenic acid-chitosan conjugate was synthesized by introducing of chlorogenic acid onto chitosan with the aid of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and hydroxybenzotriazole. The data of UV-vis, FT-IR and NMR for chlorogenic acid-chitosan conjugates demonstrated the successful conjugation of chlorogenic acid with chitosan. Compared to chitosan, chlorogenic acid-chitosan conjugates exhibited increased solubility in distilled water, 1% acetic acid solution (v/v) or 50% ethanol solution (v/v) containing 0.5% acetic acid. Moreover, chlorogenic acid-chitosan conjugates showed dramatic enhancements in metal ion chelating activity, total antioxidant capacity, scavenging activities on 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) and superoxide radicals, inhibitory effects on lipid peroxidation and β-carotene-linoleic acid bleaching, and protective effect on H 2 O 2 -induced oxidative injury of PC12 cells. Particularly, chlorogenic acid-chitosan conjugate exhibited higher inhibitory effects on lipid peroxidation and β-carotene-linoleic acid bleaching than chlorogenic acid. The results suggested that chlorogenic acid-chitosan conjugates could serve as food supplements to enhance the function of foods in future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Concentration Dependence of Gold Nanoparticles for Fluorescence Enhancement

NASA Astrophysics Data System (ADS)

Solomon, Joel; Wittmershaus, Bruce

Noble metal nanoparticles possess a unique property known as surface plasmon resonance in which the conduction electrons oscillate due to incoming light, dramatically increasing their absorption and scattering of light. The oscillating electrons create a varying electric field that can affect nearby molecules. The fluorescence and photostability of fluorophores can be enhanced significantly when they are near plasmonic nanoparticles. This effect is called metal enhanced fluorescence (MEF). MEF from two fluorescence organic dyes, Lucifer Yellow CH and Riboflavin, was measured with different concentrations of 50-nm colloidal gold nanoparticles (Au-NP). The concentration range of Au-NP was varied from 2.5 to 250 pM. To maximize the interaction, the dyes were chosen so their emission spectra had considerable overlap with the absorption spectra of the Au-NP, which is common in MEF studies. If the dye molecules are too close to the surface of Au-NP, fluorescence quenching can occur instead of MEF. To try to observe this difference, silica-coated Au-NP were compared to citrate-based Au-NP; however, fluorescence quenching was observed with both Au-NP. This material is based upon work supported by the National Science Foundation under Grant Number NSF-ECCS-1306157.

Windows into Children's Thinking: A Guide to Storytelling and Dramatization

ERIC Educational Resources Information Center

Wright, Cheryl; Bacigalupa, Chiara; Black, Tyler; Burton, Michael

2008-01-01

Telling and dramatizing stories is an increasingly popular addition to the preschool curriculum, largely due to the attention this activity has received through the writings of Vivian Paley (Bad guys don't have birthdays: fantasy play at four. The University of Chicago Press, Chicago, 1988; The boy who would be a helicopter: the uses of…

High Temperature Induced Anthocyanin Inhibition and Active Degradation in Malus profusion

PubMed Central

Rehman, Rana Naveed Ur; You, Yaohua; Zhang, Lei; Goudia, Bachir Daoura; Khan, Abdul Rehman; Li, Pengmin; Ma, Fangwang

2017-01-01

The red fleshed fruits of Malus profusion represent gradual color loss during high temperature in summer, potentially due to active degradation of anthocyanin. The objective of this study was to examine both physiological and molecular evidence of anthocyanin degradation. Malus crabapple fruits were exposed to either room temperature (RT = 18 ± 2°C: 25 ± 2°C) or high temperature (HT = 33 ± 2°C: 25 ± 2°C) regimens (12 h: 12 h) under hypoxic (2%) or normoxic (21%) oxygen levels. The results showed that the concentration of cyanidin 3-galactoside (cy-3-gal) was dramatically reduced following HT treatments due to a significant down-regulation of anthocyanin biosynthetic genes (MpCHS, MpDFR, MpLDOX, MpUFGT, and MpMYB10). Among other repressor MYBs, MpMYB15 expression was high following HT treatment of the fruit. HT led to the generation of a substantial concentration of H2O2 due to enhanced activities of superoxide dismutase (SOD), methane dicarboxylic aldehyde (MDA) content and cell sap pH value. Similarly, transcript levels of MpVHA-B1 and MpVHA-B2 were reduced which are involved in the vacuolar transportation of anthocyanin. The enzymatic degradation of anthocyanin was eventually enhanced coupled with the oxidative activities of peroxidase (POD) and H2O2. Conversely, the RT treatments potentially enhanced anthocyanin content by stabilizing physiological attributes (such as MDA, H2O2, and pH, among others) and sustaining sufficient biosynthetic gene expression levels. Quantitative real-time PCR analysis indicated that the transcription of MpPOD1, MpPOD8 and MpPOD9 genes in fruit tissues was up-regulated due to HT treatment and that hypoxic conditions seems more compatible with the responsible POD isoenzymes involved in active anthocyanin degradation. The results of the current study could be useful for understanding as well as elucidating the physiological phenomenon and molecular signaling cascade underlying active anthocyanin degradation in Malus crops. PMID:28848597

Five Years of Enhanced "HSTW" in Texas: Raising Achievement and Preparing Students for College and Careers through Dedicated Implementation of the "HSTW" Key Practices.

ERIC Educational Resources Information Center

Southern Regional Education Board (SREB), 2011

2011-01-01

The Texas Education Agency (TEA) and the Southern Regional Education Board (SREB) joined hands in 2005 to enhance dramatically implementation of the "High Schools That Work" ("HSTW") improvement design in the state. Between 2005 and 2010, nearly 50 high schools in five cohorts joined the Texas Enhanced "HSTW" Network…

Surface-enhanced Raman scattering on tunable plasmonic nanoparticle substrates

PubMed Central

Jackson, J. B.; Halas, N. J.

2004-01-01

Au and Ag nanoshells are investigated as substrates for surface-enhanced Raman scattering (SERS). We find that SERS enhancements on nanoshell films are dramatically different from those observed on colloidal aggregates, specifically that the Raman enhancement follows the plasmon resonance of the individual nanoparticles. Comparative finite difference time domain calculations of fields at the surface of smooth and roughened nanoshells reveal that surface roughness contributes only slightly to the total enhancement. SERS enhancements as large as 2.5 × 1010 on Ag nanoshell films for the nonresonant molecule p-mercaptoaniline are measured. PMID:15608058

Reduced Ensemble Plasmon Line Widths and Enhanced Two-Photon Luminescence in Anodically Formed High Surface Area Au-TiO2 3D Nanocomposites.

PubMed

Farsinezhad, Samira; Banerjee, Shyama Prasad; Bangalore Rajeeva, Bharath; Wiltshire, Benjamin D; Sharma, Himani; Sura, Anton; Mohammadpour, Arash; Kar, Piyush; Fedosejevs, Robert; Shankar, Karthik

2017-01-11

Localized surface plasmon resonances (LSPR) in TiO 2 nanorod and nanotube arrays decorated by gold nanoparticles can be exploited to improve photocatalytic activity, enhance nonlinear optical coefficients, and increase light harvesting in solar cells. However, the LSPR typically has a low quality factor, and the resonance is often obscured by the Urbach tail of the TiO 2 band gap absorption. Attempts to increase the LSPR extinction intensity by increasing the density of gold nanoparticles on the surface of the TiO 2 nanostructures invariably produce peak broadening due to the effects of either agglomeration or polydispersity. We present a new class of hybrid nanostructures containing gold nanoparticles (NPs) partially embedded in nanoporous/nanotubular TiO 2 by performing the anodization of cosputtered Ti-Au thin films containing a relatively high ratio of Au:Ti. Our method of anodizing thin film stacks containing alternate layers of Ti and TiAu results in very distinctive LSPR peaks with quality factors as high as 6.9 and ensemble line widths as small as 0.33 eV even in the presence of an Urbach tail. Unusual features in the anodization of such films are observed and explained, including oscillatory current transients and the observation of coherent heterointerfaces between the Au NPs and anatase TiO 2 . We further show that such a plasmonic NP-embedded nanotube structure dramatically outperforms a plasmonic NP-decorated anodic nanotube structure in terms of the extinction coefficient, and achieves a strongly enhanced two-photon fluorescence due to the high density of gold nanoparticles in the composite film and the plasmonic local field enhancement.

Ecological prediction with nonlinear multivariate time-frequency functional data models

USGS Publications Warehouse

Yang, Wen-Hsi; Wikle, Christopher K.; Holan, Scott H.; Wildhaber, Mark L.

2013-01-01

Time-frequency analysis has become a fundamental component of many scientific inquiries. Due to improvements in technology, the amount of high-frequency signals that are collected for ecological and other scientific processes is increasing at a dramatic rate. In order to facilitate the use of these data in ecological prediction, we introduce a class of nonlinear multivariate time-frequency functional models that can identify important features of each signal as well as the interaction of signals corresponding to the response variable of interest. Our methodology is of independent interest and utilizes stochastic search variable selection to improve model selection and performs model averaging to enhance prediction. We illustrate the effectiveness of our approach through simulation and by application to predicting spawning success of shovelnose sturgeon in the Lower Missouri River.

Intra-Brillouin-zone bandgaps due to periodic misalignment in one-dimensional magnetophotonic crystals

NASA Astrophysics Data System (ADS)

Wang, Fei; Lakhtakia, Akhlesh

2008-01-01

One-dimensional (1D) magnetophotonic crystals (MPCs) can incorporate optical gyrotropy induced by a bias magnetic field, crystalline misalignment, and differential linear birefringence in a single photonic-crystal structure. A 1D MPC whose unit cell contains two layers—one magnetophotonic, the other not—displays intra-Brillouin-zone photonic bandgaps (PBGs) in the Brillouin diagram. While the optical gyrotropy makes the PBG bandwidths tunable by a bias magnetic field, the bicrystalline misalignment modifies and can even trump this magnetic tunability. Magnetic tunability is greatly affected by a proper selection of the two materials; e.g., a large birefringence ratio between the two layers can dramatically enhance the magnetic tunability of the MPC. We also expect our 1D MPCs to be useful for detecting magnetic fields.

Emerging biomarkers for cancer immunotherapy in melanoma.

PubMed

Axelrod, Margaret L; Johnson, Douglas B; Balko, Justin M

2017-09-14

The treatment and prognosis of metastatic melanoma has changed substantially since the advent of novel immune checkpoint inhibitors (ICI), agents that enhance the anti-tumor immune response. Despite the success of these agents, clinically actionable biomarkers to aid patient and regimen selection are lacking. Herein, we summarize and review the evidence for candidate biomarkers of response to ICIs in melanoma. Many of these candidates can be examined as parts of a known molecular pathway of immune response, while others are clinical in nature. Due to the ability of ICIs to illicit dramatic and durable responses, well-validated biomarkers that can be effectively implemented in the clinic will require strong negative predictive values that do not limit patients with who may benefit from ICI therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phosphoketolase pathway engineering for carbon-efficient biocatalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henard, Calvin Andrew; Freed, Emily Frances; Guarnieri, Michael Thomas

2015-12-01

Recent advances in metabolic engineering have facilitated the development of microbial biocatalysts capable of producing an array of bio-products, ranging from fuels to drug molecules. These bio-products are commonly generated through an acetyl-CoA intermediate, which serves as a key precursor in the biological conversion of carbon substrates. Moreover, conventional biocatalytic upgrading strategies proceeding through this route are limited by low carbon efficiencies, in large part due to carbon losses associated with pyruvate decarboxylation to acetyl-CoA. Bypass of pyruvate decarboxylation offers a means to dramatically enhance carbon yields and, in turn, bioprocess economics. Here, we discuss recent advances and prospects formore » employing the phosphoketolase pathway for direct biosynthesis of acetyl-CoA from carbon substrates, and phosphoketolase-based metabolic engineering strategies for carbon efficient biocatalysis.« less

Long range ordered alloys modified by addition of niobium and cerium

DOEpatents

Liu, C.T.

1984-08-22

Long range ordered alloys are described having the nominal composition (Fe,Ni,Co)/sub 3/ (V,M) where M is a ductility enhancing metal selected from the group Ti, Zr, Hf with additions of small amounts of cerium and niobium to dramatically enhance the creep properties of the resulting alloys.

Novel and remarkable enhanced-fluorescence system based on gold nanoclusters for detection of tetracycline.

PubMed

Yang, Xiaoming; Zhu, Shanshan; Dou, Yao; Zhuo, Yan; Luo, Yawen; Feng, Yuanjiao

2014-05-01

Tetracycline and Eu(3+), while coexisting, usually appear as a complex by chelating. This complex shows low fluorescence intensity, leading to its limitation of analytical goals. Gold nanoclusters (AuNCs), emerging as novel nano-material, are attracting increasing attentions in multiple fields. Herein, gold nanoclusters first function as a fluorescence-enhanced reagent rather than a conventional fluorescent-probe, and a dramatic enhanced-fluorescence system was built based on Eu(3+)-Tetracycline complex (EuTC) by introducing gold nanoclusters. Simultaneously, three types of gold nanoclusters were employed for exploring various conditions likely affecting the system, which demonstrate that no other gold nanoclusters than DNA-templated gold nanoclusters enormously caused fluorescence-enhancement of EuTC. Moreover, this enhanced-fluorescence system permitted available detection of tetracycline (TC) in a linear range of 0.01-5 μM, with a detection limit of 4 nM at a signal-to-noise ratio of 3. Significantly, the practicality of this method for detection of TC in human urine and milk samples was validated, demonstrating its advantages of simplicity, sensitivity and low cost. Interestingly, this system described here is probably promising for kinds of applications based on its dramatically enhanced-fluorescence. © 2013 Published by Elsevier B.V.

Nanocrystals feel the heat

NASA Astrophysics Data System (ADS)

Liang, Liangliang; Liu, Xiaogang

2018-03-01

Phosphors often suffer luminescence quenching at elevated temperatures. Now, thermal quenching can be combated with surface phonon-assisted energy transfer, enabling the luminescence of ultrasmall upconversion nanophosphors to be dramatically enhanced.

Energy Transport in the Thermosphere During the Solar Storms of April 2002

NASA Technical Reports Server (NTRS)

Mlynczak, Martin G.; Martin-Torres, F. J.; Crowley, Geoff; Funke, Bernd; Lu, Gang; Russell, III, James M.; Kozyra, Janet; Sharma, Ramesh; Gordley, Larry; Paxton, Larry

2005-01-01

The dramatic solar storm events of April 2002 deposited a large amount of energy into the Earth's upper atmosphere, substantially altering the thermal structure, the chemical composition, the dynamics, and the radiative environment. We examine the flow of energy within the thermosphere during this storm period from the perspective of infrared radiation transport and heat conduction. Observations from the SABER instrument on the TIMED satellite are coupled with computations based on the ASPEN thermospheric general circulation model to assess the energy flow. The dominant radiative response is associated with dramatically enhanced infrared emission from nitric oxide at 5.3 microns from which a total of approx. 7.7 x 10(exp 23) ergs of energy are radiated during the storm. Energy loss rates due to NO emission exceed 2200 Kelvin per day. In contrast, energy loss from carbon dioxide emission at 15 microns is only approx. 2.3% that of nitric oxide. Atomic oxygen emission at 63 microns is essentially constant during the storm. Energy loss from molecular heat conduction may be as large as 3.8% of the NO emission. These results confirm the "natural thermostat" effect of nitric oxide emission as the primary mechanism by which storm energy is lost from the thermosphere below 210 km.

Rapid enhancement of low energy (<100 eV) ion flux in response to interplanetary shocks based on two Van Allen Probes case studies: Implications for source regions and heating mechanisms

DOE PAGES

Yue, Chao; Li, Wen; Reeves, Geoffrey D.; ...

2016-07-01

Interactions between interplanetary (IP) shocks and the Earth's magnetosphere manifest many important space physics phenomena including low-energy ion flux enhancements and particle acceleration. In order to investigate the mechanisms driving shock-induced enhancement of low-energy ion flux, we have examined two IP shock events that occurred when the Van Allen Probes were located near the equator while ionospheric and ground observations were available around the spacecraft footprints. We have found that, associated with the shock arrival, electromagnetic fields intensified, and low-energy ion fluxes, including H +, He +, and O +, were enhanced dramatically in both the parallel and perpendicular directions.more » During the 2 October 2013 shock event, both parallel and perpendicular flux enhancements lasted more than 20 min with larger fluxes observed in the perpendicular direction. In contrast, for the 15 March 2013 shock event, the low-energy perpendicular ion fluxes increased only in the first 5 min during an impulse of electric field, while the parallel flux enhancement lasted more than 30 min. In addition, ionospheric outflows were observed after shock arrivals. From a simple particle motion calculation, we found that the rapid response of low-energy ions is due to drifts of plasmaspheric population by the enhanced electric field. Furthermore, the fast acceleration in the perpendicular direction cannot solely be explained by E × B drift but betatron acceleration also plays a role. Adiabatic acceleration may also explain the fast response of the enhanced parallel ion fluxes, while ion outflows may contribute to the enhanced parallel fluxes that last longer than the perpendicular fluxes.« less

Rapid enhancement of low energy (<100 eV) ion flux in response to interplanetary shocks based on two Van Allen Probes case studies: Implications for source regions and heating mechanisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yue, Chao; Li, Wen; Reeves, Geoffrey D.

Interactions between interplanetary (IP) shocks and the Earth's magnetosphere manifest many important space physics phenomena including low-energy ion flux enhancements and particle acceleration. In order to investigate the mechanisms driving shock-induced enhancement of low-energy ion flux, we have examined two IP shock events that occurred when the Van Allen Probes were located near the equator while ionospheric and ground observations were available around the spacecraft footprints. We have found that, associated with the shock arrival, electromagnetic fields intensified, and low-energy ion fluxes, including H +, He +, and O +, were enhanced dramatically in both the parallel and perpendicular directions.more » During the 2 October 2013 shock event, both parallel and perpendicular flux enhancements lasted more than 20 min with larger fluxes observed in the perpendicular direction. In contrast, for the 15 March 2013 shock event, the low-energy perpendicular ion fluxes increased only in the first 5 min during an impulse of electric field, while the parallel flux enhancement lasted more than 30 min. In addition, ionospheric outflows were observed after shock arrivals. From a simple particle motion calculation, we found that the rapid response of low-energy ions is due to drifts of plasmaspheric population by the enhanced electric field. Furthermore, the fast acceleration in the perpendicular direction cannot solely be explained by E × B drift but betatron acceleration also plays a role. Adiabatic acceleration may also explain the fast response of the enhanced parallel ion fluxes, while ion outflows may contribute to the enhanced parallel fluxes that last longer than the perpendicular fluxes.« less

Layers of 'Cape Verde' in 'Victoria Crater' (Enhanced)

NASA Technical Reports Server (NTRS)

2006-01-01

This view of Victoria crater is looking north from 'Duck Bay' towards the dramatic promontory called 'Cape Verde.' The dramatic cliff of layered rocks is about 50 meters (about 165 feet) away from the rover and is about 6 meters (about 20 feet) tall. The taller promontory beyond that is about 100 meters (about 325 feet) away, and the vista beyond that extends away for more than 400 meters (about 1300 feet) into the distance. This is a false color rendering (enhanced to bring out details from within the shadowed regions of the scene) of images taken by the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity during the rover's 952nd sol, or Martian day, (Sept. 28, 2006) using the camera's 750-nanometer, 530-nanometer and 430-nanometer filters.

Assessing the osteoblast transcriptome in a model of enhanced bone formation due to constitutive Gs-G protein signaling in osteoblasts

PubMed Central

Wattanachanya, Lalita; Wang, Liping; Millard, Susan M.; Lu, Wei-Dar; O’Carroll, Dylan; Hsiao, Edward C.; Conklin, Bruce R.; Nissenson, Robert A.

2015-01-01

G protein–coupled receptor (GPCR) signaling in osteoblasts (OBs) is an important regulator of bone formation. We previously described a mouse model expressing Rs1, an engineered constitutively active Gs-coupled GPCR, under the control of the 2.3-kb Col I promoter. These mice showed a dramatic age-dependent increase in trabecular bone of femurs. Here, we further evaluated the effects of enhanced Gs signaling in OBs on intramembranous bone formation by examining calvariae of 1- and 9-week-old Col1(2.3)/Rs1 mice and characterized the in vivo gene expression specifically occurring in osteoblasts with activated Gs G protein–coupled receptor signaling, at the cellular level rather than in a whole bone. Rs1 calvariae displayed a dramatic increase in bone volume with partial loss of cortical structure. By immunohistochemistry, Osterix was detected in cells throughout the inter-trabecular space while Osteocalcin was expressed predominantly in cells along bone surfaces, suggesting the role of paracrine mediators secreted from OBs driven by 2.3-kb Col I promoter could influence early OB commitment, differentiation, and/or proliferation. Gene expression analysis of calvarial OBs revealed that genes affected by Rs1 signaling include those encoding proteins important for cell differentiation, cytokines and growth factors, angiogenesis, coagulation, and energy metabolism. The set of Gs-GPCRs and other GPCRs that may contribute to the observed skeletal phenotype and candidate paracrine mediators of the effect of Gs signaling in OBs were also determined. Our results identify novel detailed in vivo cellular changes of the anabolic response of the skeleton to Gs signaling in mature OBs. PMID:25704759

Quantifying the impact of bathymetric changes on the hydrological regimes in a large floodplain lake: Poyang Lake

NASA Astrophysics Data System (ADS)

Yao, Jing; Zhang, Qi; Ye, Xuchun; Zhang, Dan; Bai, Peng

2018-06-01

The hydrological regime of a lake is largely dependent on its bathymetry. A dramatic water level reduction has occurred in Poyang Lake in recent years, coinciding with significant bed erosion. Few studies have focused on the influence of bathymetric changes on the hydrological regime in such a complex river-lake floodplain system. This study combined hydrological data and a physically based hydrodynamic model to quantify the influence of the bathymetric changes (1998-2010) on the water level spatiotemporal distribution in Poyang Lake, based on a dry year (2006), a wet year (2010) and an average year (2000-2010). The following conclusions can be drawn from the results of this study: (1) The bed erosion of the northern outlet channel averaged 3 m, resulting in a decrease in the water level by 1.2-2 m in the northern channels (the most significantly influenced areas) and approximately 0.3 m in the central lake areas during low-level periods. The water levels below 16 m and 14 m were significantly affected during the rising period and recession period, respectively. The water level reduction was enhanced due to lower water levels. (2) The water surface profiles adjusted, and the rising and recession rates of the water level increased by 0.5-3.1 cm/d at the lake outlet. The bathymetric influence extended across the entire lake due to the emptying effect, resulting in a change in the water level distribution. The average annual outflow increased by 6.8%. (3) The bathymetric changes contributed approximately 14.4% to the extreme low water level in autumn 2006 and enhanced the drought in the dry season. This study quantified the impact of the bathymetric changes on the lake water levels, thereby providing a better understanding of the potential effects of continued sand mining operations and providing scientific explanations for the considerable variations in the hydrological regimes of Poyang Lake. Moreover, this study attempts to provide a reference for the assessment of similarly dramatic bathymetric changes in complex floodplain lakes.

Electrochemical dopamine sensor based on P-doped graphene: Highly active metal-free catalyst and metal catalyst support.

PubMed

Chu, Ke; Wang, Fan; Zhao, Xiao-Lin; Wang, Xin-Wei; Tian, Ye

2017-12-01

Heteroatom doping is an effective strategy to enhance the catalytic activity of graphene and its hybrid materials. Despite a growing interest of P-doped graphene (P-G) in energy storage/generation applications, P-G has rarely been investigated for electrochemical sensing. Herein, we reported the employment of P-G as both metal-free catalyst and metal catalyst support for electrochemical detection of dopamine (DA). As a metal-free catalyst, P-G exhibited prominent DA sensing performances due to the important role of P doping in improving the electrocatalytic activity of graphene toward DA oxidation. Furthermore, P-G could be an efficient supporting material for loading Au nanoparticles, and resulting Au/P-G hybrid showed a dramatically enhanced electrocatalytic activity and extraordinary sensing performances with a wide linear range of 0.1-180μM and a low detection limit of 0.002μM. All these results demonstrated that P-G might be a very promising electrode material for electrochemical sensor applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Hepatic FGF21 expression is induced at birth via PPARalpha in response to milk intake and contributes to thermogenic activation of neonatal brown fat.

PubMed

Hondares, Elayne; Rosell, Meritxell; Gonzalez, Frank J; Giralt, Marta; Iglesias, Roser; Villarroya, Francesc

2010-03-03

Plasma FGF21 levels and hepatic FGF21 gene expression increase dramatically after birth in mice. This induction is initiated by suckling, requires lipid intake, is impaired in PPARalpha null neonates, and is mimicked by treatment with the PPARalpha activator, Wy14,643. Neonates exhibit reduced FGF21 expression in response to fasting, in contrast to the upregulation occurring in adults. Changes in FGF21 expression due to suckling or nutritional manipulations were associated with circulating free fatty acid and ketone body levels. We mimicked the FGF21 postnatal rise by injecting FGF21 into fasting neonates, and found that this enhanced the expression of genes involved in thermogenesis within brown fat, and increased body temperature. Brown adipocytes treated with FGF21 exhibited increased expression of thermogenic genes, higher total and uncoupled respiration, and enhanced glucose oxidation. We propose that the induction of FGF21 production by the liver mediates direct activation of brown fat thermogenesis during the fetal-to-neonatal transition. 2010 Elsevier Inc. All rights reserved.

Fabrication of Cellulose Film with Enhanced Mechanical Properties in Ionic Liquid 1-Allyl-3-methylimidaxolium Chloride (AmimCl)

PubMed Central

Pang, Jinhui; Liu, Xin; Zhang, Xueming; Wu, Yuying; Sun, Runcang

2013-01-01

More and more attention has been paid to environmentally friendly bio-based renewable materials as the substitution of fossil-based materials, due to the increasing environmental concerns. In this study, regenerated cellulose films with enhanced mechanical property were prepared via incorporating different plasticizers using ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as the solvent. The characteristics of the cellulose films were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), thermal analysis (TG), X-ray diffraction (XRD), 13C Solid-state cross-polarization/magic angle spinning nuclear magnetic resonance (CP/MAS NMR) and tensile testing. The results showed that the cellulose films exhibited a homogeneous and smooth surface structure. It was noted that the thermal stability of the regenerated cellulose film plasticized with glycerol was increased compared with other regenerated cellulose films. Furthermore, the incorporation of plasticizers dramatically strengthened the tensile strength and improved the hydrophobicity of cellulose films, as compared to the control sample. Therefore, these notable results exhibited the potential utilization in producing environmentally friendly cellulose films with high performance properties. PMID:28809209

Fitness trade-offs of group formation and movement by Thomson's gazelles in the Serengeti ecosystem.

PubMed

Fryxell, John M; Berdahl, Andrew M

2018-05-19

Collective behaviours contributing to patterns of group formation and coordinated movement are common across many ecosystems and taxa. Their ubiquity is presumably due to altering interactions between individuals and their predators, resources and physical environment in ways that enhance individual fitness. On the other hand, fitness costs are also often associated with group formation. Modifications to these interactions have the potential to dramatically impact population-level processes, such as trophic interactions or patterns of space use in relation to abiotic environmental variation. In a wide variety of empirical systems and models, collective behaviour has been shown to enhance access to ephemeral patches of resources, reduce the risk of predation and reduce vulnerability to environmental fluctuation. Evolution of collective behaviour should accordingly depend on the advantages of collective behaviour weighed against the costs experienced at the individual level. As an illustrative case study, we consider the potential trade-offs on Malthusian fitness associated with patterns of group formation and movement by migratory Thomson's gazelles in the Serengeti ecosystem.This article is part of the theme issue 'Collective movement ecology'. © 2018 The Authors.

A small amount of dietary carbohydrate can promote the HFD-induced insulin resistance to a maximal level.

PubMed

Mei, Shuang; Yang, Xuefeng; Guo, Huailan; Gu, Haihua; Zha, Longying; Cai, Junwei; Li, Xuefeng; Liu, Zhenqi; Bennett, Brian J; He, Ling; Cao, Wenhong

2014-01-01

Both dietary fat and carbohydrates (Carbs) may play important roles in the development of insulin resistance. The main goal of this study was to further define the roles for fat and dietary carbs in insulin resistance. C57BL/6 mice were fed normal chow diet (CD) or HFD containing 0.1-25.5% carbs for 5 weeks, followed by evaluations of calorie consumption, body weight and fat gains, insulin sensitivity, intratissue insulin signaling, ectopic fat, and oxidative stress in liver and skeletal muscle. The role of hepatic gluconeogenesis in the HFD-induced insulin resistance was determined in mice. The role of fat in insulin resistance was also examined in cultured cells. HFD with little carbs (0.1%) induced severe insulin resistance. Addition of 5% carbs to HFD dramatically elevated insulin resistance and 10% carbs in HFD was sufficient to induce a maximal level of insulin resistance. HFD with little carbs induced ectopic fat accumulation and oxidative stress in liver and skeletal muscle and addition of carbs to HFD dramatically enhanced ectopic fat and oxidative stress. HFD increased hepatic expression of key gluconeogenic genes and the increase was most dramatic by HFD with little carbs, and inhibition of hepatic gluconeogenesis prevented the HFD-induced insulin resistance. In cultured cells, development of insulin resistance induced by a pathological level of insulin was prevented in the absence of fat. Together, fat is essential for development of insulin resistance and dietary carb is not necessary for HFD-induced insulin resistance due to the presence of hepatic gluconeogenesis but a very small amount of it can promote HFD-induced insulin resistance to a maximal level.

A Small Amount of Dietary Carbohydrate Can Promote the HFD-Induced Insulin Resistance to a Maximal Level

PubMed Central

Guo, Huailan; Gu, Haihua; Zha, Longying; Cai, Junwei; Li, Xuefeng; Liu, Zhenqi; Bennett, Brian J.; He, Ling; Cao, Wenhong

2014-01-01

Both dietary fat and carbohydrates (Carbs) may play important roles in the development of insulin resistance. The main goal of this study was to further define the roles for fat and dietary carbs in insulin resistance. C57BL/6 mice were fed normal chow diet (CD) or HFD containing 0.1–25.5% carbs for 5 weeks, followed by evaluations of calorie consumption, body weight and fat gains, insulin sensitivity, intratissue insulin signaling, ectopic fat, and oxidative stress in liver and skeletal muscle. The role of hepatic gluconeogenesis in the HFD-induced insulin resistance was determined in mice. The role of fat in insulin resistance was also examined in cultured cells. HFD with little carbs (0.1%) induced severe insulin resistance. Addition of 5% carbs to HFD dramatically elevated insulin resistance and 10% carbs in HFD was sufficient to induce a maximal level of insulin resistance. HFD with little carbs induced ectopic fat accumulation and oxidative stress in liver and skeletal muscle and addition of carbs to HFD dramatically enhanced ectopic fat and oxidative stress. HFD increased hepatic expression of key gluconeogenic genes and the increase was most dramatic by HFD with little carbs, and inhibition of hepatic gluconeogenesis prevented the HFD-induced insulin resistance. In cultured cells, development of insulin resistance induced by a pathological level of insulin was prevented in the absence of fat. Together, fat is essential for development of insulin resistance and dietary carb is not necessary for HFD-induced insulin resistance due to the presence of hepatic gluconeogenesis but a very small amount of it can promote HFD-induced insulin resistance to a maximal level. PMID:25055153

Near-infrared light-mediated photodynamic/photothermal therapy nanoplatform by the assembly of Fe3O4 carbon dots with graphitic black phosphorus quantum dots

PubMed Central

Zhang, Ming; Wang, Wentao; Cui, Yingjun; Zhou, Ninglin; Shen, Jian

2018-01-01

Background Recently, combined photodynamic therapy (PDT) and photothermal therapy (PTT) has become a desired treatment for cancer. However, the development of economic, high-efficiency, and safe photosensitizers/photothermal agents remains a significant challenge. Methods A novel nanocomposite has been developed via the assembly of iron oxide carbon dot (Fe3O4-CDs) nanoparticles and black phosphorus quantum dots (genipin [GP]-polyglutamic acid [PGA]-Fe3O4-CDs@BPQDs), and this nanocomposite shows a broad light-absorption band and a photodegradable character. Results In vitro and in vivo assays indicated that GP-PGA-Fe3O4-CDs@BPQDs were highly biocompatible and exhibited excellent tumor-inhibition efficacy, due to the synergistic PTT and PDT via a near-infrared laser. Importantly, in vivo tumor magnetic resonance imaging (MRI) results illustrated that GP-PGA-Fe3O4-CDs@BPQDs can be specifically applied for enhanced T2 MRI of tumors. This work presents the first combined application of a PDT and PTT effect deriving from BPQDs and MRI from Fe3O4-CDs, which may promote utilization of black BPQDs in biomedicine. Conclusion As expected, GP-PGA-Fe3O4-CDs@BPQDs displayed a dramatically enhanced ability to destroy tumor cells, due to the synergistic combination of PTT and PDT. PMID:29785107

Mitigation of Electrical Failure of Silver Nanowires under Current Flow and the Application for Long Lifetime Organic Light-Emitting Diodes

DOE PAGES

Chen, Dustin; Zhao, Fangchao; Tong, Kwing; ...

2016-07-08

Here, the extended lifetime of organic light-emitting diodes (OLEDs) based on enhanced electrical stability of a silver nanowire (AgNW) transparent conductive electrode is reported. Specifically, in depth investigation is performed on the ability of atomic layer deposition deposited zinc oxide (ZnO) on AgNWs to render the nanowires electrically stable during electrical stressing at the range of operational current density used for OLED lighting. ZnO-coated AgNWs have been observed to show no electrical, optical, or morphological degradation, while pristine AgNW electrodes have become unusable for optoelectronic devices due to dramatic decreases in conductivity, transparency, and fragmentation of the nanowire network atmore » ≈150 mA cm -2. When fabricated into OLED substrates, resulting OLEDs fabricated on the ZnO-AgNW platform exhibit a 140% increase in lifetime when compared to OLEDs fabricated on indium tin oxide (ITO)/glass, and ≈20% when compared to OLEDs fabricated on AgNW based substrates. While both ZnO-coated and pristine AgNW substrates outperform ITO/glass due to the lower current densities required to drive the device, morphological stability in response to current stressing is responsible for the enhancement of lifetime of ZnO-AgNW based OLEDs compared to pristine AgNW based OLEDs.« less

Enhancement of waste activated sludge dewaterability using calcium peroxide pre-oxidation and chemical re-flocculation.

PubMed

Chen, Zhan; Zhang, Weijun; Wang, Dongsheng; Ma, Teng; Bai, Runying; Yu, Dezhong

2016-10-15

The effects of combined calcium peroxide (CaO2) oxidation with chemical re-flocculation on dewatering performance and physicochemical properties of waste activated sludge was investigated in this study. The evolutions of extracellular polymeric substances (EPS) distribution, composition and morphological properties were analyzed to unravel the sludge conditioning mechanism. It was found that sludge filtration performance was enhanced by calcium peroxide oxidation with the optimal dosage of 20 mg/gTSS. However, this enhancement was not observed at lower dosages due to the absence of oxidation and the performance deteriorated at higher dosages because of the release of excess EPS, mainly as protein-like substances. The variation in soluble EPS (SEPS) component can be fitted well with pseudo-zero-order kinetic model under CaO2 treatment. At the same time, extractable EPS content (SEPS and loosely bound EPS (LB-EPS)) were dramatically increased, indicating sludge flocs were effectively broken and their structure became looser after CaO2 addition. The sludge floc structure was reconstructed and sludge dewaterability was significantly enhanced using chemical re-flocculation (polyaluminium chloride (PACl), ferric iron (FeCl3) and polyacrylamide (PAM)). The inorganic coagulants performed better in improving sludge filtration dewatering performance and reducing cake moisture content than organic polymer, since they could act as skeleton builders and decrease the sludge compressibility. Copyright © 2016 Elsevier Ltd. All rights reserved.

The taste of KCl - What a difference a sugar makes.

PubMed

Ben Abu, Natalie; Harries, Daniel; Voet, Hillary; Niv, Masha Y

2018-07-30

Dramatic increase in NaCl consumption lead to sodium intake beyond health guidelines. KCl substitution helps reduce sodium intake but results in a bitter-metallic off-taste. Two disaccharides, trehalose and sucrose, were tested in order to untangle the chemical (increase in effective concentration of KCl due to sugar addition) from the sensory effects. The bitter-metallic taste of KCl was reduced by these sugars, while saltiness was enhanced or unaltered. The perceived sweetness of sugar, regardless of its type and concentration, was an important factor in KCl taste modulation. Though KCl was previously shown to increase the chemical activity of trehalose but not of sucrose, we found that it suppressed the perceived sweetness of both sugars. Therefore, sensory integration was the dominant factor in the tested KCl-sugar combinations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enrichment of low-molecular-weight proteins from biofluids for biomarker discovery.

PubMed

Chertov, Oleg; Simpson, John T; Biragyn, Arya; Conrads, Thomas P; Veenstra, Timothy D; Fisher, Robert J

2005-01-01

The dramatic progress in mass spectrometry-based methods of protein identification has triggered a new quest for disease-associated biomarkers. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and its variant surface-enhanced laser desorption/ionization mass spectrometry, provide effective means to explore the less studied information slice of the human serum proteome -- low-molecular-weight proteins and peptides. These low-molecular-weight proteins and peptides are promising for the detection of important biomarkers. Due to the significant experimental problems imposed by high-abundance and high-molecular-weight proteins, it is important to effectively remove these species prior to mass spectrometry analysis of the low-molecular-weight serum and plasma proteomes. In this review, the advantages afforded by recently introduced methods for prefractionation of serum, as they pertain to the detection and identification of biomarkers, will be discussed.

A factor involved in efficient breakdown of supersonic streamwise vortices

NASA Astrophysics Data System (ADS)

Hiejima, Toshihiko

2015-03-01

Spatially developing processes in supersonic streamwise vortices were numerically simulated at Mach number 5.0. The vortex evolution largely depended on the azimuthal vorticity thickness of the vortices, which governs the negative helicity profile. Large vorticity thickness greatly enhanced the centrifugal instability, with consequent development of perturbations with competing wavenumbers outside the vortex core. During the transition process, supersonic streamwise vortices could generate large-scale spiral structures and a number of hairpin like vortices. Remarkably, the transition caused a dramatic increase in the total fluctuation energy of hypersonic flows, because the negative helicity profile destabilizes the flows due to helicity instability. Unstable growth might also relate to the correlation length between the axial and azimuthal vorticities of the streamwise vortices. The knowledge gained in this study is important for realizing effective fuel-oxidizer mixing in supersonic combustion engines.

Modulation of key reactions of the catecholamine metabolism by extracts from Eschscholtzia californica and Corydalis cava.

PubMed

Kleber, E; Schneider, W; Schäfer, H L; Elstner, E F

1995-02-01

Aqueous-alcoholic extracts from Eschscholtzia californica inhibit the enzymatic degradation of catecholamines as well as the synthesis of adrenaline, whereas aqueous-ethanolic extracts from Corydalis cava enhance the chemical oxidation of adrenaline and the synthesis of melanine from dihydroxyphenylalanine (DOPA). Both extracts dramatically shorten the lag phase in the catalysis of phenolase probably due to their o-diphenol content, where the Corydalis extracts are 10 times more active than the Eschscholtzia preparations. Dopamine beta-hydroxylase and monoamine oxidase (MAO-B) are especially inhibited by Eschscholtzia extracts. Diamine oxidases are inhibited by both preparations to a similar extent. The results of this study may be interpreted as a cooperative function of the two preparations in establishing and preserving high catecholamine levels thus explaining their sedative, antidepressive and hypnotic activities.

Psychological stress exerts an adjuvant effect on skin dendritic cell functions in vivo.

PubMed

Saint-Mezard, Pierre; Chavagnac, Cyril; Bosset, Sophie; Ionescu, Marius; Peyron, Eric; Kaiserlian, Dominique; Nicolas, Jean-Francois; Bérard, Frédéric

2003-10-15

Psychological stress affects the pathophysiology of infectious, inflammatory, and autoimmune diseases. However, the mechanisms by which stress could modulate immune responses in vivo are poorly understood. In this study, we report that application of a psychological stress before immunization exerts an adjuvant effect on dendritic cell (DC), resulting in increased primary and memory Ag-specific T cell immune responses. Acute stress dramatically enhanced the skin delayed-type hypersensitivity reaction to haptens, which is mediated by CD8(+) CTLs. This effect was due to increased migration of skin DCs, resulting in augmented CD8(+) T cell priming in draining lymph nodes and enhanced recruitment of CD8(+) T cell effectors in the skin upon challenge. This adjuvant effect of stress was mediated by norepinephrine (NE), but not corticosteroids, as demonstrated by normalization of the skin delayed-type hypersensitivity reaction and DC migratory properties following selective depletion of NE. These results suggest that release of NE by sympathetic nerve termini during a psychological stress exerts an adjuvant effect on DC by promoting enhanced migration to lymph nodes, resulting in increased Ag-specific T cell responses. Our findings may open new ways in the treatment of inflammatory diseases, e.g., psoriasis, allergic contact dermatitis, and atopic dermatitis.

Early bilingualism enhances mechanisms of false-belief reasoning.

PubMed

Kovács, Agnes Melinda

2009-01-01

In their first years, children's understanding of mental states seems to improve dramatically, but the mechanisms underlying these changes are still unclear. Such 'theory of mind' (ToM) abilities may arise during development, or have an innate basis, developmental changes reflecting limitations of other abilities involved in ToM tasks (e.g. inhibition). Special circumstances such as early bilingualism may enhance ToM development or other capacities required by ToM tasks. Here we compare 3-year-old bilinguals and monolinguals on a standard ToM task, a modified ToM task and a control task involving physical reasoning. The modified ToM task mimicked a language-switch situation that bilinguals often encounter and that could influence their ToM abilities. If such experience contributes to an early consolidation of ToM in bilinguals, they should be selectively enhanced in the modified task. In contrast, if bilinguals have an advantage due to better executive inhibitory abilities involved in ToM tasks, they should outperform monolinguals on both ToM tasks, inhibitory demands being similar. Bilingual children showed an advantage on the two ToM tasks but not on the control task. The precocious success of bilinguals may be associated with their well-developed control functions formed during monitoring and selecting languages.

Chemotherapy-Induced Macrophage Infiltration into Tumors Enhances Nanographene-Based Photodynamic Therapy.

PubMed

Zhao, Yang; Zhang, Chenran; Gao, Liquan; Yu, Xinhe; Lai, Jianhao; Lu, Dehua; Bao, Rui; Wang, Yanpu; Jia, Bing; Wang, Fan; Liu, Zhaofei

2017-11-01

Increased recruitment of tumor-associated macrophages (TAM) to tumors following chemotherapy promotes tumor resistance and recurrence and correlates with poor prognosis. TAM depletion suppresses tumor growth, but is not highly effective due to the effects of tumorigenic mediators from other stromal sources. Here, we report that adoptive macrophage transfer led to a dramatically enhanced photodynamic therapy (PDT) effect of 2-(1-hexyloxyethyl)-2-devinyl pyropheophor-bide-alpha (HPPH)-coated polyethylene glycosylated nanographene oxide [GO(HPPH)-PEG] by increasing its tumor accumulation. Moreover, tumor treatment with commonly used chemotherapeutic drugs induced an increase in macrophage infiltration into tumors, which also enhanced tumor uptake and the PDT effects of GO(HPPH)-PEG, resulting in tumor eradication. Macrophage recruitment to tumors after chemotherapy was visualized noninvasively by near-infrared fluorescence and single-photon emission CT imaging using F4/80-specific imaging probes. Our results demonstrate that chemotherapy combined with GO(HPPH)-PEG PDT is a promising strategy for the treatment of tumors, especially those resistant to chemotherapy. Furthermore, TAM-targeted molecular imaging could potentially be used to predict the efficacy of combination therapy and select patients who would most benefit from this treatment approach. Cancer Res; 77(21); 6021-32. ©2017 AACR . ©2017 American Association for Cancer Research.

Resource Prospector: Mission Goals, Relevance and Site Selection

NASA Technical Reports Server (NTRS)

Colaprete, A.; Elphic, R. C.; Andrews, D.; Sanders, G.; McGovern, A.; Vaughan, R.; Heldmann, J.; Trimble, J.

2015-01-01

Over the last two decades a wealth of new observations of the moon have demonstrated a lunar water system dramatically more complex and rich than was deduced following the Apollo era. Observation from the Lunar Prospector Neutron Spectrometer (LPNS) revealed enhancements of hydrogen near the lunar poles. This observation has since been confirmed by the Lunar Reconnaissance Orbiter (LRO) Lunar Exploration Neutron Detector (LEND) instrument. The Lunar Crater Observation and Sensing Satellite (LCROSS) mission targeted a permanently shadowed, enhanced hydrogen location within the crater Cabeus. The LCROSS impact showed that at least some of the hydrogen enhancement is in the form of water ice and molecular hydrogen (H2). Other volatiles were also observed in the LCROSS impact cloud, including CO2, CO, an H2S. These volatiles, and in particular water, have the potential to be a valuable or enabling resource for future exploration. In large part due to these new findings, the NASA Human Exploration and Operations Mission Directorate (HEOMD) have selected a lunar volatiles prospecting mission for a concept study and potential flight in CY2020. The mission includes a rover-borne payload that (1) can locate surface and near-subsurface volatiles, (2) excavate and analyze samples of the volatile-bearing regolith (up to 1 meter), and (3) demonstrate the form, extractability and usefulness of the materials.

Talking Rocks.

ERIC Educational Resources Information Center

Rice, Dale; Corley, Brenda

1987-01-01

Discusses some of the ways that rocks can be used to enhance children's creativity and their interest in science. Suggests the creation of a dramatic production involving rocks. Includes basic information on sedimentary, igneous, and metamorphic rocks. (TW)

Signal enhancement in ligand-receptor interactions using dynamic polymers at quartz crystal microbalance sensors.

PubMed

Dunér, Gunnar; Anderson, Henrik; Pei, Zhichao; Ingemarsson, Björn; Aastrup, Teodor; Ramström, Olof

2016-06-20

The signal enhancement properties of QCM sensors based on dynamic, biotinylated poly(acrylic acid) brushes has been studied in interaction studies with an anti-biotin Fab fragment. The poly(acrylic acid) sensors showed a dramatic increase in signal response with more than ten times higher signal than the carboxyl-terminated self-assembled monolayer surface.

Integrating Internet Video Conferencing Techniques and Online Delivery Systems with Hybrid Classes to Enhance Student Interaction and Learning in Accelerated Programs

ERIC Educational Resources Information Center

Beckwith, E. George; Cunniff, Daniel T.

2009-01-01

Online course enrollment has increased dramatically over the past few years. The authors cite the reasons for this rapid growth and the opportunities open for enhancing teaching/learning techniques such as video conferencing and hybrid class combinations. The authors outlined an example of an accelerated learning, eight-class session course…

When does fading enhance perceptual category learning?

PubMed

Pashler, Harold; Mozer, Michael C

2013-07-01

Training that uses exaggerated versions of a stimulus discrimination (fading) has sometimes been found to enhance category learning, mostly in studies involving animals and impaired populations. However, little is known about whether and when fading facilitates learning for typical individuals. This issue was explored in 7 experiments. In Experiments 1 and 2, observers discriminated stimuli based on a single sensory continuum (time duration and line length, respectively). Adaptive fading dramatically improved performance in training (unsurprisingly) but did not enhance learning as assessed in a final test. The same was true for nonadaptive linear fading (Experiment 3). However, when variation in length (predicting category membership) was embedded among other (category-irrelevant) variation, fading dramatically enhanced not only performance in training but also learning as assessed in a final test (Experiments 4 and 5). Fading also helped learners to acquire a color saturation discrimination amid category-irrelevant variation in hue and brightness, although this learning proved transitory after feedback was withdrawn (Experiment 7). Theoretical implications are discussed, and we argue that fading should have practical utility in naturalistic category learning tasks, which involve extremely high dimensional stimuli and many irrelevant dimensions. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Reemergence of sea ice cover anomalies and the role of the sea ice-albedo feedback in CCSM simulations

NASA Astrophysics Data System (ADS)

Deweaver, E. T.

2008-12-01

The dramatic sea ice decline of 2007 and lack of recovery in 2008 raise the question of a "tipping point" for Arctic sea ice, beyond which the transition to a seasonal sea ice state becomes abrupt and irreversible. The tipping point is essentially a "memory catastrophe", in which a dramatic loss of sea ice in one summer is "remembered" in reduced ice thickness over the winter season and leads to a comparably dramatic loss the following summer. The dominant contributor to this memory is presumably the sea ice - albedo feedback (SIAF), in which excess insolation absorbed due to low summer ice cover leads to a shorter ice growth season and hence thinner ice. While these dynamics are clearly important, they are difficult to quantify given the lack of long-term observations in the Arctic and the suddenness of the recent loss. Alternatively, we attempt to quantify the contribution of the SIAF to the year-to-year memory of sea ice cover anomalies in simulations of the NCAR Community Climate System Model (CCSM) under 20th century conditions. Lagged autocorrelation plots of sea ice area anomalies show that anomalies in one year tend to "reemerge" in the following year. Further experiments using a slab ocean model (SOM) are used to assess the contribution of oceanic processes to the year-to-year reemergence. This contribution is substantial, particularly in the winter season, and includes memory due to the standard mixed layer reemergence mechanism and low-frequency ocean heat transport anomalies. The contribution of the SIAF to persistence in the SOM experiment is determined through additional experiments in which the SIAF is disabled by fixing surface albedo to its climatological value regardless of sea ice concentration anomalies. SIAF causes a 50% increase in the magnitude of the anomalies but a relatively small increase in their persistence. Persistence is not dramatically increased because the enhancement of shortwave flux anomalies by SIAF is compensated by stronger turbulent heat flux losses in the cold season. The role of turbulent heat fluxes is somewhat inconsistent with the retrospective 20th century simulations from PIOMAS, in which increased insolation is balanced by longwave heat loss. By fitting the area anomaly time series for the SIAF and no-SIAF integrations to an AR1 process, the change in net feedback due to SIAF is calculated. The change in net feedback implies that SIAF increases the climate sensitivity of September sea ice to external forcing (greenhouse gas increases) by about 20%. The modest increase in sea ice sensitivity is confirmed by further climate change experiments with and without SIAF with the CCSM/SOM model. The small role for SIAF is somewhat surprising given the prevalence of "abrupt loss" events in CCSM climate change simulations. However, it is consistent with claims that the dominant factor in abrupt loss events is the sea ice thickness at the event onset.

Improved dielectric constant and breakdown strength of γ-phase dominant super toughened polyvinylidene fluoride/TiO2 nanocomposite film: an excellent material for energy storage applications and piezoelectric throughput

NASA Astrophysics Data System (ADS)

Mehebub Alam, Md; Ghosh, Sujoy Kumar; Sarkar, Debabrata; Sen, Shrabanee; Mandal, Dipankar

2017-01-01

Titanium dioxide (TiO2) nanoparticles (NPs) embedded γ-phase containing polyvinylidene fluoride (PVDF) nanocomposite (PNC) film turns to an excellent material for energy storage application due to an increased dielectric constant (32 at 1 kHz), enhanced electric breakdown strength (400 MV m-1). It also exhibits a high energy density of 4 J cm-3 which is 25 times higher than that of virgin PVDF. 98% of the electroactive γ-phase has been acheived by the incorporation of TiO2 NPs and the resulting PNC behaves like a super-toughened material due to a dramatic improvement (more than 80%) in the tensile strength. Owing to their electroactive nature and extraordinary mechanical properties, PNC films have a strong ability to fabricate the piezoelectric nanogenerators (PNGs) that have recently been an area of focus regarding mechanical energy harvesting. The feasibility of piezoelectric voltage generation from PNGs is demostrated under the rotating fan that also promises further utility such as rotational speed (RPM) determination.

Two-Step Reactive Aid Sintering of BaZr0.8Y0.2O3- δ Proton-Conducting Ceramics

NASA Astrophysics Data System (ADS)

Wang, Siwei; Chen, Yan; Zhang, Lingling; Ren, Cong; Chen, Fanglin; Brinkman, Kyle S.

2015-12-01

Ceramic-based proton conductors enable high-temperature hydrogen economy applications such as hydrogen separation membranes, fuel cells, and steam electrolyzers. BaZr0.8Y0.2O3- δ (BZY) proton-conducting oxide possesses the highest level of proton conductivity reported to date, but poor sinterability hinders its widespread utilization. In this paper, we report a two-step reactive aid sintering (TRAS) method involving the introduction of BaCO3 and B2O3-Li2O for the preparation of dense BZY ceramics sintered at 1500°C. The resulting BZY samples showed a pure perovskite structure with a dramatic increase in the relative density to 91.5%. In addition, the shrinkage during sintering was improved to 19.3% by a TRAS method as compared to 2.6% by the conventional solid date reaction method. The bulk conductivity was improved due to enhanced densification, while the grain boundary conductivity decreased due to the blocking behavior of the sintering aid resulting in a decrease in the total conductivity of the samples.

Two-Step Reactive Aid Sintering of BaZr 0.8Y 0.2O 3-δ Proton-Conducting Ceramics

DOE PAGES

Wang, Siwei; Chen, Yan; Zhang, Lingling; ...

2015-10-14

Ceramic-based proton conductors enable high-temperature hydrogen economy applications such as hydrogen separation membranes, fuel cells, and steam electrolyzers. BaZr 0.8Y 0.2O 3-δ (BZY) proton-conducting oxide possesses the highest level of proton conductivity reported to date, but poor sinterability hinders its widespread utilization. Here, we report a two-step reactive aid sintering (TRAS) method involving the introduction of BaCO 3 and B 2O 3-Li 2O for the preparation of dense BZY ceramics sintered at 1500°C. The resulting BZY samples showed a pure perovskite structure with a dramatic increase in the relative density to 91.5%. In addition, the shrinkage during sintering was improvedmore » to 19.3% by a TRAS method as compared to 2.6% by the conventional solid date reaction method. Moreover, the bulk conductivity was improved due to enhanced densification, while the grain boundary conductivity decreased due to the blocking behavior of the sintering aid resulting in a decrease in the total conductivity of the samples.« less

Advanced manufacturing: Technology and international competitiveness

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tesar, A.

1995-02-01

Dramatic changes in the competitiveness of German and Japanese manufacturing have been most evident since 1988. All three countries are now facing similar challenges, and these challenges are clearly observed in human capital issues. Our comparison of human capital issues in German, Japanese, and US manufacturing leads us to the following key judgments: Manufacturing workforces are undergoing significant changes due to advanced manufacturing technologies. As companies are forced to develop and apply these technologies, the constituency of the manufacturing workforce (especially educational requirements, contingent labor, job content, and continuing knowledge development) is being dramatically and irreversibly altered. The new workforcemore » requirements which result due to advanced manufacturing require a higher level of worker sophistication and responsibility.« less

Driving of Dramatic Geomagnetic Activity by Enhancement of Meso-Scale Polar-cap Flows

NASA Astrophysics Data System (ADS)

Lyons, L. R.; Gallardo-Lacourt, B.; Zou, Y.; Nishimura, Y.; Anderson, P. C.; Angelopoulos, V.; Ruohoniemi, J. M.; Mitchell, E. J.; Paxton, L. J.; Nishitani, N.

2017-12-01

Recent studies have shown that mesoscale flows are common within the polar cap ionosphere. They often cross the magnetic separatrix, and become are critical to the driving of geomagnetic activity. They lead, for example, to plasma sheet flow bursts, auroral poleward boundary intensifications, auroral streamers, substorms, auroral omega bands, and poleward motion of the polar cap boundary from reconnection. We have found large enhancements of these meso-scale ionospheric polar cap flows heading towards the nightside separatrix. These enhancements are common immediately after the impact of CME shocks under southward IMF, but can also occur in other situations, including without substantial change in the solar wind or IMF. These meso-scale flow enhancements, which must extent outward along magnetospheric field lines from the ionosphere, are seen to drive an almost immediate strong auroral, ionospheric and field-aligned current, and reconnection activity. The resulting activity is particularly dramatic during the initiation of CME storms, but may reflect a more generally occurring phenomenon of mesoscale flow enhancements leading to similar oval responses without a shock impact, including during and following the expansion phase some substorms. If this phenomenon is indeed common, it could lead to possibly fundamental questions, such as when do polar cap convection enhancements lead to a substorm growth phase versus leading directly to strong poleward expansion of, and strong activity within, the auroral oval field line region? Another critical question would be what leads to and causes the enhancements in meso-scale polar cap flows?

Enhanced cell uptake via non-covalent decollation of a single-walled carbon nanotube-DNA hybrid with polyethylene glycol-grafted poly(l-lysine) labeled with an Alexa-dye and its efficient uptake in a cancer cell

NASA Astrophysics Data System (ADS)

Fujigaya, Tsuyohiko; Yamamoto, Yuki; Kano, Arihiro; Maruyama, Atsushi; Nakashima, Naotoshi

2011-10-01

The use of single-walled carbon nanotubes (SWNTs) for biomedical applications is a promising approach due to their unique outer optical stimuli response properties, such as a photothermal response triggered by near-IR laser irradiation. The challenging task in order to realize such applications is to render the SWNTs biocompatible. For this purpose, the stable and homogeneous functionalization of the SWNTs with a molecule carrying a biocompatible group is very important. Here, we describe the design and synthesis of a polyanionic SWNT/DNA hybrid combined with a cationic poly(l-lysine) grafted by polyethylene glycol (PLL-g-PEG) to provide a supramolecular SWNT assembly. A titration experiment revealed that the assembly undergoes an approximately 1 : 1 reaction of the SWNT/DNA with PLL-g-PEG. We also found that SWNT/DNA is coated with PLL-g-PEG very homogeneously that avoids the non-specific binding of proteins on the SWNT surface. The experiment using the obtained supramolecular hybrid was carried out in vitro and a dramatic enhancement in the cell uptake efficiency compared to that of the SWNT/DNA hybrid without PLL-g-PEG was found.The use of single-walled carbon nanotubes (SWNTs) for biomedical applications is a promising approach due to their unique outer optical stimuli response properties, such as a photothermal response triggered by near-IR laser irradiation. The challenging task in order to realize such applications is to render the SWNTs biocompatible. For this purpose, the stable and homogeneous functionalization of the SWNTs with a molecule carrying a biocompatible group is very important. Here, we describe the design and synthesis of a polyanionic SWNT/DNA hybrid combined with a cationic poly(l-lysine) grafted by polyethylene glycol (PLL-g-PEG) to provide a supramolecular SWNT assembly. A titration experiment revealed that the assembly undergoes an approximately 1 : 1 reaction of the SWNT/DNA with PLL-g-PEG. We also found that SWNT/DNA is coated with PLL-g-PEG very homogeneously that avoids the non-specific binding of proteins on the SWNT surface. The experiment using the obtained supramolecular hybrid was carried out in vitro and a dramatic enhancement in the cell uptake efficiency compared to that of the SWNT/DNA hybrid without PLL-g-PEG was found. Electronic supplementary information (ESI) available: Additional absorption spectra, DLS plots and PL spectra. See DOI: 10.1039/c1nr10635j

Heat Shock-Enhanced Conjugation Efficiency in Standard Campylobacter jejuni Strains

PubMed Central

Zeng, Ximin; Ardeshna, Devarshi

2015-01-01

Campylobacter jejuni, the leading bacterial cause of human gastroenteritis in the United States, displays significant strain diversity due to horizontal gene transfer. Conjugation is an important horizontal gene transfer mechanism contributing to the evolution of bacterial pathogenesis and antimicrobial resistance. It has been observed that heat shock could increase transformation efficiency in some bacteria. In this study, the effect of heat shock on C. jejuni conjugation efficiency and the underlying mechanisms were examined. With a modified Escherichia coli donor strain, different C. jejuni recipient strains displayed significant variation in conjugation efficiency ranging from 6.2 × 10−8 to 6.0 × 10−3 CFU per recipient cell. Despite reduced viability, heat shock of standard C. jejuni NCTC 11168 and 81-176 strains (e.g., 48 to 54°C for 30 to 60 min) could dramatically enhance C. jejuni conjugation efficiency up to 1,000-fold. The phenotype of the heat shock-enhanced conjugation in C. jejuni recipient cells could be sustained for at least 9 h. Filtered supernatant from the heat shock-treated C. jejuni cells could not enhance conjugation efficiency, which suggests that the enhanced conjugation efficiency is independent of secreted substances. Mutagenesis analysis indicated that the clustered regularly interspaced short palindromic repeats system and the selected restriction-modification systems (Cj0030/Cj0031, Cj0139/Cj0140, Cj0690c, and HsdR) were dispensable for heat shock-enhanced conjugation in C. jejuni. Taking all results together, this study demonstrated a heat shock-enhanced conjugation efficiency in standard C. jejuni strains, leading to an optimized conjugation protocol for molecular manipulation of this organism. The findings from this study also represent a significant step toward elucidation of the molecular mechanism of conjugative gene transfer in C. jejuni. PMID:25911489

Heat Shock-Enhanced Conjugation Efficiency in Standard Campylobacter jejuni Strains.

PubMed

Zeng, Ximin; Ardeshna, Devarshi; Lin, Jun

2015-07-01

Campylobacter jejuni, the leading bacterial cause of human gastroenteritis in the United States, displays significant strain diversity due to horizontal gene transfer. Conjugation is an important horizontal gene transfer mechanism contributing to the evolution of bacterial pathogenesis and antimicrobial resistance. It has been observed that heat shock could increase transformation efficiency in some bacteria. In this study, the effect of heat shock on C. jejuni conjugation efficiency and the underlying mechanisms were examined. With a modified Escherichia coli donor strain, different C. jejuni recipient strains displayed significant variation in conjugation efficiency ranging from 6.2 × 10(-8) to 6.0 × 10(-3) CFU per recipient cell. Despite reduced viability, heat shock of standard C. jejuni NCTC 11168 and 81-176 strains (e.g., 48 to 54°C for 30 to 60 min) could dramatically enhance C. jejuni conjugation efficiency up to 1,000-fold. The phenotype of the heat shock-enhanced conjugation in C. jejuni recipient cells could be sustained for at least 9 h. Filtered supernatant from the heat shock-treated C. jejuni cells could not enhance conjugation efficiency, which suggests that the enhanced conjugation efficiency is independent of secreted substances. Mutagenesis analysis indicated that the clustered regularly interspaced short palindromic repeats system and the selected restriction-modification systems (Cj0030/Cj0031, Cj0139/Cj0140, Cj0690c, and HsdR) were dispensable for heat shock-enhanced conjugation in C. jejuni. Taking all results together, this study demonstrated a heat shock-enhanced conjugation efficiency in standard C. jejuni strains, leading to an optimized conjugation protocol for molecular manipulation of this organism. The findings from this study also represent a significant step toward elucidation of the molecular mechanism of conjugative gene transfer in C. jejuni. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Prep-ME Software Implementation and Enhancement

DOT National Transportation Integrated Search

2017-09-01

Highway agencies across the United States are moving from empirical design procedures towards the mechanistic-empirical (ME) based pavement design. Even though the Pavement ME Design presents a new paradigm shift with several dramatic improvements, i...

Plasmon enhanced Raman scattering effect for an atom near a carbon nanotube

DOE PAGES

Bondarev, I. V.

2015-01-01

Quantum electrodynamics theory of the resonance Raman scattering is developed for an atom in a close proximity to a carbon nanotube. The theory predicts a dramatic enhancement of the Raman intensity in the strong atomic coupling regime to nanotube plasmon near-fields. This resonance scattering is a manifestation of the general electromagnetic surface enhanced Raman scattering effect, and can be used in designing efficient nanotube based optical sensing substrates for single atom detection, precision spontaneous emission control, and manipulation.

Altruism: A natural strategy for enhancing survival

NASA Astrophysics Data System (ADS)

Rozenfeld, Alejandro F.; Luis Gruver, José; Albano, Ezequiel V.; Havlin, Shlomo

2006-09-01

We study the influence of altruistic behavior in a prey-predator model permitting the preys to commit suicide by confronting the predators instead of escaping. Surprising, altruistic behavior at microscopic (local) scale, leads to the emergence of new complex macroscopic (global) phenomena characterized by dramatic changes in the dynamic topology of the prey-predator spatiotemporal distribution, yielding spiral patterns. We show that such dynamics enhances the prey's survivability.

Hole-Accepting-Ligand-Modified CdSe QDs for Dramatic Enhancement of Photocatalytic and Photoelectrochemical Hydrogen Evolution by Solar Energy.

PubMed

Li, Xu-Bing; Liu, Bin; Wen, Min; Gao, Yu-Ji; Wu, Hao-Lin; Huang, Mao-Yong; Li, Zhi-Jun; Chen, Bin; Tung, Chen-Ho; Wu, Li-Zhu

2016-04-01

Solar H 2 evolution of CdSe QDs can be significantly enhanced simply by introducing a suitable hole-accepting-ligand for achieving efficient hole extraction and transfer at the nanoscale interfaces, which opens an effective pathway for dissociation of excitons to generate long-lived charge separation, thus improving the solar-to-fuel conversion efficiency.

Site-directed mutagenesis of the hinge peptide from the hemagglutinin protein: enhancement of the pH-responsive conformational change.

PubMed

Casali, Monica; Banta, Scott; Zambonelli, Carlo; Megeed, Zaki; Yarmush, Martin L

2008-06-01

Environmentally responsive proteins and peptides are increasingly finding utility in various engineered systems due to their ability to respond to the presentation of external stimuli. A classic example of this behavior is the influenza hemagglutinin (HA) fusion protein. At neutral pH, HA exists in a non-fusogenic state, but upon exposure to low pH, the conformation of the structure changes to expose a fusogenic peptide. During this structural change, massive rearrangements occur in a subunit of HA (HA2). Crystallography data has shown that a loop of 28 amino acids (residues 54-81) undergoes a dramatic transition from a random coil to an alpha-helix. This segment connects to two flanking helical regions (short and long) to form a long, continuous helix. Here, we report the results of site-directed mutagenesis study on LOOP-36 to further understand the mechanism of this important stimulus-responsive peptide. The conformational transition of a bacterially expressed LOOP-36 was found to be less dramatic than has been previously reported. The systematic mutation of glutamate and histidine residues in the peptide to glutamines (glutamine scanning) did not impact the conformational behavior of the peptide, but the substitution of the glycine residue at position 22 with alanine resulted in significant pH-responsive behavior. Therefore this mutant stimulus-responsive peptide may be more valuable for future protein engineering and bionanotechnology efforts.

Survival of introduced phosphate-solubilizing bacteria (PSB) and their impact on microbial community structure during the phytoextraction of Cd-contaminated soil.

PubMed

Jeong, Seulki; Moon, Hee Sun; Shin, Doyun; Nam, Kyoungphile

2013-12-15

This study was conducted to investigate whether or not phosphate-solubilizing bacteria (PSB) as a kind of plant growth promoting rhizobacteria enhance the uptake of Cd by plants. In addition, the effect of PSB augmentation during phytoextraction on the microbial community of indigenous soil bacteria was also studied. In the initial Cd-contaminated soil, the major phyla were Proteobacteria (35%), Actinobacteria (38%) and Firmicutes (8%). While Proteobacteria were dominant at the second and sixth week (41 and 54%, respectively) in inoculated soil, Firmicutes (mainly belonging to the Bacilli class-61%), dramatically increased in the eight-week soil. For the uninoculated soil, the proportion of α-Proteobacteria increased after eight weeks (32%). Interestingly, Actinobacteria class, which was originally present in the soil (37%), seemed to disappear during phytoremediation, irrespective of whether PSB was inoculated or not. Cluster analysis and Principal Component Analysis revealed that the microbial community of eight-week inoculated soil was completely separated from the other soil samples, due to the dramatic increase of Bacillus aryabhattai. These findings revealed that it took at least eight weeks for the inoculated Bacillus sp. to functionally adapt to the introduced soil, against competition with indigenous microorganisms in soil. An ecological understanding of interaction among augmented bacteria, plant and indigenous soil bacteria is needed, for proper management of phytoextraction. Copyright © 2013 Elsevier B.V. All rights reserved.

Case for Deploying Complex Systems Utilizing Commodity Components

NASA Technical Reports Server (NTRS)

Bryant, Barry S.; Pitts, R. Lee

2003-01-01

When the International Space Station (ISS) finally reached an operational state, many of the Payload Operations and Integration Facility (POIF) hardware components were reaching end of life, COTS product costs were soaring, and the ISS budget was becoming severely constrained. However, most requirement development was complete. In addition, the ISS program is a fully functioning program with at least fifteen years of operational life remaining. Therefore it is critical that any upgrades, refurbishments, or enhancements be accomplished in realtime with minimal disruptions to service. For these and other reasons, it was necessary to ensure the viability of the POIF. Due to the to the breadth of capability of the POIF (a NASA ground station), it is believed that the lessons to be learned by other complex systems are applicable and any solutions garnered by the POIF are applicable to other complex systems as well. With that in mind, a number of new approaches have been investigated to increase the portability of the POIF and reduce the cost of refurbishment, operations, and maintenance. These new approaches were directed at the Total Cost of Ownership (TCO); not only the refurbishment but also current operational difficulties, licensing, and anticipation of the next refurbishment. Our basic premise is that technology had evolved dramatically since the concept of the POIF ground system and we should leverage our experience on this new technological landscape. Fortunately, Moore's law and market forces have changed the landscape considerably. These changes are manifest in five (5) ways that are particularly relevant to POIF: 1. Complex Instruction Set Computing (CISC) processors have advanced to unprecedented levels of compute capacity with a dramatic cost break, 2. Linux has become a major operating system supported by most vendors on a broad range of platforms, 3. Windows(TradeMark) based desktops are pervasive in the office environment, 4. Stable and affordable WindowsTM development environments and tools are available and offer a rich set of capabilities, 5. The WindowsTM 2000 provides a stable client platform, Therefore, five studies were proposed, developed, and are in the current process of deployment which dramatically reduces the cost of operations, maintenance, refurbishment, and deployment of a ground system. Restating and refining the basic premise stated earlier, it is possible to enhance operations through the replacement of hardware and software components with commodity based items wherever applicable. This will dramatically reduce the overall lifecycle cost of the project. The first study leveraged the POIF S secure, three-tier, web architecture to replace the client workstations with lower cost PC platforms. A second study initiated a review of COTS products to examine the level of added value of each product. This study included replacement of some COTS products with custom code, deletions, substitutions, and consolidation of COTS products. Studies three and four reviewed the server architectures of the data distribution systems and Enhanced HOSC System (EHS) command and telemetry system to propose migration to new platforms, both software and hardware. The final study reviewed current IP communication technologies, developed an operational model for flight operations, and demonstrated that voice over IP was practical and could be integrated into operations.

Enhanced Performance of Recycled Aggregate Concrete with Atomic Polymer Technology

DOT National Transportation Integrated Search

2012-06-01

The atomic polymer technology in form of mesoporous inorganic polymer (MIP) can effectively improve material durability and performance of concrete by dramatically increase inter/intragranular bond strength of concrete at nano-scale. The strategy of ...

Structural Enhancements to Adapt to Impacts of Climate Change

DOT National Transportation Integrated Search

2016-06-01

With the apparent evolution towards more extreme weather including hurricanes and tropical storms, state transportation agencies are realizing the need for adaptive infrastructure systems that can react and adapt to these events. However, dramatic ch...

Directed evolution of an ultrastable carbonic anhydrase for highly efficient carbon capture from flue gas

DOE PAGES

Alvizo, Oscar; Nguyen, Luan J.; Savile, Christopher K.; ...

2014-11-03

Carbonic anhydrase (CA) is one of nature’s fastest enzymes and can dramatically improve the economics of carbon capture under demanding environments such as coal-fired power plants. The use of CA to accelerate carbon capture is limited by the enzyme’s sensitivity to the harsh process conditions. Using directed evolution, the properties of a β-class CA from Desulfovibrio vulgaris were dramatically enhanced. Iterative rounds of library design, library generation, and high-throughput screening identified highly stable CA variants that tolerate temperatures of up to 107 °C in the presence of 4.2 M alkaline amine solvent at pH >10.0. This increase in thermostability andmore » alkali tolerance translates to a 4,000,000-fold improvement over the natural enzyme. In conclusion, at pilot scale, the evolved catalyst enhanced the rate of CO2 absorption 25-fold compared with the noncatalyzed reaction.« less

Directed evolution of an ultrastable carbonic anhydrase for highly efficient carbon capture from flue gas

PubMed Central

Alvizo, Oscar; Nguyen, Luan J.; Savile, Christopher K.; Bresson, Jamie A.; Lakhapatri, Satish L.; Solis, Earl O. P.; Fox, Richard J.; Broering, James M.; Benoit, Michael R.; Zimmerman, Sabrina A.; Novick, Scott J.; Liang, Jack; Lalonde, James J.

2014-01-01

Carbonic anhydrase (CA) is one of nature’s fastest enzymes and can dramatically improve the economics of carbon capture under demanding environments such as coal-fired power plants. The use of CA to accelerate carbon capture is limited by the enzyme’s sensitivity to the harsh process conditions. Using directed evolution, the properties of a β-class CA from Desulfovibrio vulgaris were dramatically enhanced. Iterative rounds of library design, library generation, and high-throughput screening identified highly stable CA variants that tolerate temperatures of up to 107 °C in the presence of 4.2 M alkaline amine solvent at pH >10.0. This increase in thermostability and alkali tolerance translates to a 4,000,000-fold improvement over the natural enzyme. At pilot scale, the evolved catalyst enhanced the rate of CO2 absorption 25-fold compared with the noncatalyzed reaction. PMID:25368146

Gene doping: a review of performance-enhancing genetics.

PubMed

Gaffney, Gary R; Parisotto, Robin

2007-08-01

Unethical athletes and their mentors have long arrogated scientific and medical advances to enhance athletic performance, thus gaining a dishonest competitive advantage. Building on advances in genetics, a new threat arises from athletes using gene therapy techniques in the same manner that some abused performance-enhancing drugs were used. Gene doping, as this is known, may produce spectacular physiologic alterations to dramatically enhance athletic abilities or physical appearance. Furthermore, gene doping may present pernicious problems for the regulatory agencies and investigatory laboratories that are entrusted to keep sporting events fair and ethical. Performance-enhanced genetics will likewise present unique challenges to physicians in many spheres of their practice.

Enhancing optical response of graphene through stochastic resonance

NASA Astrophysics Data System (ADS)

Ying, Lei; Huang, Liang; Lai, Ying-Cheng

2018-04-01

Enhancing the optical response of graphene is a topic of interest with applications in optoelectronics. Subject to light irradiation, graphene can exhibit nontrivial topologically insulating states, effectively turning itself into a Floquet topological insulator due to the time periodicity of the external driving. We find that, when random disorder is present, its interplay with the topologically insulating states can have a dramatic effect on electronic transport through graphene. In particular, we consider the prototypical setting where a graphene nanoribbon is irradiated by circularly polarized light, where the length of the nanoribbon is sufficiently long so that evanescent states have little effect on transport. We uncover a resonance phenomenon in which the conductance is enhanced as the disorder strength is increased from zero, reaches a maximum value for an optimal level of disorder, and decreases as the disorder is strengthened further. With respect to its value at the zero-disorder strength, the maximum conductance value can be as much as 50 % higher. Qualitatively, this can be understood as a result of the dynamical interplay between disorder and Floquet states (channels) generated by light irradiation. Quantitatively, the resonance phenomenon can be explained in the framework of Born theory, where the disorder reorganizes the Floquet Hamiltonian and enhances the effective coupling between the adjacent Floquet conducting channels. That is, disorder is capable of promoting both photon absorption and emission, leading to significant enhancement of nonequilibrium electronic transport. We demonstrate the robustness of the resonance phenomenon by investigating the effects of spatial symmetry breaking on transport and provide an understanding based on analyzing the behavior of the density of states of the Floquet channels.

Glucose 6-phosphate dehydrogenase deficiency enhances germ cell apoptosis and causes defective embryogenesis in Caenorhabditis elegans.

PubMed

Yang, H-C; Chen, T-L; Wu, Y-H; Cheng, K-P; Lin, Y-H; Cheng, M-L; Ho, H-Y; Lo, S J; Chiu, D T-Y

2013-05-02

Glucose 6-phosphate dehydrogenase (G6PD) deficiency, known as favism, is classically manifested by hemolytic anemia in human. More recently, it has been shown that mild G6PD deficiency moderately affects cardiac function, whereas severe G6PD deficiency leads to embryonic lethality in mice. How G6PD deficiency affects organisms has not been fully elucidated due to the lack of a suitable animal model. In this study, G6PD-deficient Caenorhabditis elegans was established by RNA interference (RNAi) knockdown to delineate the role of G6PD in animal physiology. Upon G6PD RNAi knockdown, G6PD activity was significantly hampered in C. elegans in parallel with increased oxidative stress and DNA oxidative damage. Phenotypically, G6PD-knockdown enhanced germ cell apoptosis (2-fold increase), reduced egg production (65% of mock), and hatching (10% of mock). To determine whether oxidative stress is associated with G6PD knockdown-induced reproduction defects, C. elegans was challenged with a short-term hydrogen peroxide (H2O2). The early phase egg production of both mock and G6PD-knockdown C. elegans were significantly affected by H2O2. However, H2O2-induced germ cell apoptosis was more dramatic in mock than that in G6PD-deficient C. elegans. To investigate the signaling pathways involved in defective oogenesis and embryogenesis caused by G6PD knockdown, mutants of p53 and mitogen-activated protein kinase (MAPK) pathways were examined. Despite the upregulation of CEP-1 (p53), cep-1 mutation did not affect egg production and hatching in G6PD-deficient C. elegans. Neither pmk-1 nor mek-1 mutation significantly affected egg production, whereas sek-1 mutation further decreased egg production in G6PD-deficient C. elegans. Intriguingly, loss of function of sek-1 or mek-1 dramatically rescued defective hatching (8.3- and 9.6-fold increase, respectively) induced by G6PD knockdown. Taken together, these findings show that G6PD knockdown reduces egg production and hatching in C. elegans, which are possibly associated with enhanced oxidative stress and altered MAPK pathways, respectively.

HIV-1 Promotes Intake of Leishmania Parasites by Enhancing Phosphatidylserine-Mediated, CD91/LRP-1-Dependent Phagocytosis in Human Macrophages

PubMed Central

Lodge, Robert; Ouellet, Michel; Barat, Corinne; Andreani, Guadalupe; Kumar, Pranav; Tremblay, Michel J.

2012-01-01

Over the past decade, the number of reported human immunodeficiency virus type-1 (HIV-1)/Leishmania co-infections has risen dramatically, particularly in regions where both diseases are endemic. Although it is known that HIV-1 infection leads to an increase in susceptibility to Leishmania infection and leishmaniasis relapse, little remains known on how HIV-1 contributes to Leishmania parasitaemia. Both pathogens infect human macrophages, and the intracellular growth of Leishmania is increased by HIV-1 in co-infected cultures. We now report that uninfected bystander cells, not macrophages productively infected with HIV-1, account for enhanced phagocytosis and higher multiplication of Leishmania parasites. This effect can be driven by HIV-1 Tat protein and transforming growth factor-beta (TGF-β). Furthermore, we show for the first time that HIV-1 infection increases surface expression of phosphatidylserine receptor CD91/LRP-1 on human macrophages, thereby leading to a Leishmania uptake by uninfected bystander cells in HIV-1-infected macrophage populations. The more important internalization of parasites is due to interactions between the scavenger receptor CD91/LRP-1 and phosphatidylserine residues exposed at the surface of Leishmania. We determined also that enhanced CD91/LRP-1 surface expression occurs rapidly following HIV-1 infection, and is triggered by the activation of extracellular TGF-β. Thus, these results establish an intricate link between HIV-1 infection, Tat, surface CD91/LRP-1, TGF-β, and enhanced Leishmania phosphatidylserine-mediated phagocytosis. PMID:22412921

Carbon nanotubes as nanotexturing agents for high power supercapacitors based on seaweed carbons.

PubMed

Raymundo-Piñero, Encarnación; Cadek, Martin; Wachtler, Mario; Béguin, François

2011-07-18

The advantages provided by multiwalled carbon nanotubes (CNTs) as backbones for composite supercapacitor electrodes are discussed. This paper particularly highlights the electrochemical properties of carbon composites obtained by pyrolysis of seaweed/CNTs blends. Due to the nanotexturing effect of CNTs, supercapacitors fabricated with electrodes from these composites exhibit enhanced electrochemical performances compared with CNT-free carbons. The cell resistance is dramatically reduced by the excellent conductivity of CNTs and by the good propagation of ions favored by the presence of opened mesopores. As a consequence, the specific power of supercapacitors based on these nanocomposites is very high. Another advantage related to the presence of CNTs is a better life cycle of the systems. The composite electrodes are resilient during the charge/discharge of capacitors; these are able to perfectly accommodate the dimensional changes appearing in the active material without mechanical damages. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Subtle spectral effects accompanying the assembly of bacteriochlorophylls into cyclic light harvesting complexes revealed by high-resolution fluorescence spectroscopy

NASA Astrophysics Data System (ADS)

Rätsep, Margus; Pajusalu, Mihkel; Linnanto, Juha Matti; Freiberg, Arvi

2014-10-01

We have observed that an assembly of the bacteriochloropyll a molecules into B850 and B875 groups of cyclic bacterial light-harvesting complexes LH2 and LH1, respectively, results an almost total loss of the intra-molecular vibronic structure in the fluorescence spectrum, and simultaneously, an essential enhancement of its phonon sideband due to electron-phonon coupling. While the suppression of the vibronic coupling in delocalized (excitonic) molecular systems is predictable, as also confirmed by our model calculations, a boost of the electron-phonon coupling is rather unexpected. The latter phenomenon is explained by exciton self-trapping, promoted by mixing the molecular exciton states with charge transfer states between the adjacent chromophores in the tightly packed B850 and B875 arrangements. Similar, although less dramatic trends were noted for the light-harvesting complexes containing chlorophyll pigments.

Near-field thermal rectification devices using phase change periodic nanostructure.

PubMed

Ghanekar, Alok; Tian, Yanpei; Ricci, Matthew; Zhang, Sinong; Gregory, Otto; Zheng, Yi

2018-01-22

We theoretically analyze two near-field thermal rectification devices: a radiative thermal diode and a thermal transistor that utilize a phase change material to achieve dynamic control over heat flow by exploiting metal-insulator transition of VO 2 near 341 K. The thermal analogue of electronic diode allows high heat flow in one direction while it restricts the heat flow when the polarity of temperature gradient is reversed. We show that with the introduction of 1-D rectangular grating, thermal rectification is dramatically enhanced in the near-field due to reduced tunneling of surface waves across the interfaces for negative polarity. The radiative thermal transistor also works around phase transition temperature of VO 2 and controls heat flow. We demonstrate a transistor-like behavior wherein heat flow across the source and the drain can be greatly varied by making a small change in gate temperature.

Processing of Cryo-EM Movie Data.

PubMed

Ripstein, Z A; Rubinstein, J L

2016-01-01

Direct detector device (DDD) cameras dramatically enhance the capabilities of electron cryomicroscopy (cryo-EM) due to their improved detective quantum efficiency (DQE) relative to other detectors. DDDs use semiconductor technology that allows micrographs to be recorded as movies rather than integrated individual exposures. Movies from DDDs improve cryo-EM in another, more surprising, way. DDD movies revealed beam-induced specimen movement as a major source of image degradation and provide a way to partially correct the problem by aligning frames or regions of frames to account for this specimen movement. In this chapter, we use a self-consistent mathematical notation to explain, compare, and contrast several of the most popular existing algorithms for computationally correcting specimen movement in DDD movies. We conclude by discussing future developments in algorithms for processing DDD movies that would extend the capabilities of cryo-EM even further. © 2016 Elsevier Inc. All rights reserved.

Environmental geology and hydrology

NASA Astrophysics Data System (ADS)

Nakić, Zoran; Mileusnić, Marta; Pavlić, Krešimir; Kovač, Zoran

2017-10-01

Environmental geology is scientific discipline dealing with the interactions between humans and the geologic environment. Many natural hazards, which have great impact on humans and their environment, are caused by geological settings. On the other hand, human activities have great impact on the physical environment, especially in the last decades due to dramatic human population growth. Natural disasters often hit densely populated areas causing tremendous death toll and material damage. Demand for resources enhanced remarkably, as well as waste production. Exploitation of mineral resources deteriorate huge areas of land, produce enormous mine waste and pollute soil, water and air. Environmental geology is a broad discipline and only selected themes will be presented in the following subchapters: (1) floods as natural hazard, (2) water as geological resource and (3) the mining and mineral processing as types of human activities dealing with geological materials that affect the environment and human health.

Improved operating scenarios of the DIII-D tokamak as a result of the addition of UNIX computer systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henline, P.A.

1995-12-31

The increased use of UNIX based computer systems for machine control, data handling and analysis has greatly enhanced the operating scenarios and operating efficiency of the DIII-D tokamak. This paper will describe some of these UNIX systems and their specific uses. These include the plasma control system, the electron cyclotron heating control system, the analysis of electron temperature and density measurements and the general data acquisition system (which is collecting over 130 Mbytes of data). The speed and total capability of these systems has dramatically affected the ability to operate DIII-D. The improved operating scenarios include better plasma shape controlmore » due to the more thorough MHD calculations done between shots and the new ability to see the time dependence of profile data as it relates across different spatial locations in the tokamak. Other analysis which engenders improved operating abilities will be described.« less

Improved operating scenarios of the DIII-D tokamak as a result of the addition of UNIX computer systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henline, P.A.

1995-10-01

The increased use of UNIX based computer systems for machine control, data handling and analysis has greatly enhanced the operating scenarios and operating efficiency of the DRI-D tokamak. This paper will describe some of these UNIX systems and their specific uses. These include the plasma control system, the electron cyclotron heating control system, the analysis of electron temperature and density measurements and the general data acquisition system (which is collecting over 130 Mbytes of data). The speed and total capability of these systems has dramatically affected the ability to operate DIII-D. The improved operating scenarios include better plasma shape controlmore » due to the more thorough MHD calculations done between shots and the new ability to see the time dependence of profile data as it relates across different spatial locations in the tokamak. Other analysis which engenders improved operating abilities will be described.« less

Mesoscale Particle-Based Model of Electrophoretic Deposition

DOE PAGES

Giera, Brian; Zepeda-Ruiz, Luis A.; Pascall, Andrew J.; ...

2016-12-20

In this paper, we present and evaluate a semiempirical particle-based model of electrophoretic deposition using extensive mesoscale simulations. We analyze particle configurations in order to observe how colloids accumulate at the electrode and arrange into deposits. In agreement with existing continuum models, the thickness of the deposit increases linearly in time during deposition. Resulting colloidal deposits exhibit a transition between highly ordered and bulk disordered regions that can give rise to an appreciable density gradient under certain simulated conditions. The overall volume fraction increases and falls within a narrow range as the driving force due to the electric field increasesmore » and repulsive intercolloidal interactions decrease. We postulate ordering and stacking within the initial layer(s) dramatically impacts the microstructure of the deposits. Finally, we find a combination of parameters, i.e., electric field and suspension properties, whose interplay enhances colloidal ordering beyond the commonly known approach of only reducing the driving force.« less

Non-Fermi-liquid nature and exotic thermoelectric power in the heavy-fermion superconductor UBe13

NASA Astrophysics Data System (ADS)

Shimizu, Yusei; Pourret, Alexandre; Knebel, Georg; Palacio-Morales, Alexandra; Aoki, Dai

2015-12-01

We report quite exotic thermoelectric power S in UBe13. At 0 T, the negative S /T continues to strongly enhance down to the superconducting transition temperature with no Fermi-liquid behavior. |S /T | is dramatically suppressed and becomes rather modest with increasing field. We have also obtained precise field dependencies of (i) an anomaly in S due to an exotic Kondo effect and (ii) a field-induced anomaly in S /T associated with the anomalous upward Hc 2(T ) . In contrast to the field-sensitive transport property, the normal-state specific heat is magnetically robust, indicating that the largeness of the 5 f density of states remains in high fields. This unusual behavior in UBe13 can be explained by a considerable change in the energy derivative of the conduction-electron lifetime τc(ɛ ) at the Fermi level under magnetic fields.

Over-limiting Current and Control of Dendritic Growth by Surface Conduction in Nanopores

PubMed Central

Han, Ji-Hyung; Khoo, Edwin; Bai, Peng; Bazant, Martin Z.

2014-01-01

Understanding over-limiting current (faster than diffusion) is a long-standing challenge in electrochemistry with applications in desalination and energy storage. Known mechanisms involve either chemical or hydrodynamic instabilities in unconfined electrolytes. Here, it is shown that over-limiting current can be sustained by surface conduction in nanopores, without any such instabilities, and used to control dendritic growth during electrodeposition. Copper electrodeposits are grown in anodized aluminum oxide membranes with polyelectrolyte coatings to modify the surface charge. At low currents, uniform electroplating occurs, unaffected by surface modification due to thin electric double layers, but the morphology changes dramatically above the limiting current. With negative surface charge, growth is enhanced along the nanopore surfaces, forming surface dendrites and nanotubes behind a deionization shock. With positive surface charge, dendrites avoid the surfaces and are either guided along the nanopore centers or blocked from penetrating the membrane. PMID:25394685

A brief history of ultrasound in rheumatology: where we were.

PubMed

Grassi, Walter; Filippucci, Emilio

2014-01-01

Ultrasonography in the '70s was a well-known and widely used method within several medical specialties but not in rheumatology. Initial development of the field was led by radiologists who mainly investigated the potential of ultrasound in the assessment of large joints. In the late '80s, the first studies supporting the role of ultrasound in the detection of soft tissue changes and bone erosions in the hands of patients with rheumatoid arthritis were published. In the '90s, the dramatic improvement of spatial resolution due to the new generation high frequency probes opened up new avenues for the exploration of otherwise undetectable anatomical details. Ultrasound research during this period was enhanced by the growing use of colour Doppler and power Doppler and by the first prototypes of three dimensional ultrasound. Over the last 10 years, the buzz words in ultrasound research in rheumatology have been standardisation, early diagnosis and therapy monitoring.

Super air stable quasi-2D organic-inorganic hybrid perovskites for visible light-emitting diodes.

PubMed

Jia, Guo; Shi, Ze-Jiao; Xia, Ying-Dong; Wei, Qi; Chen, Yong-Hua; Xing, Gui-Chuan; Huang, Wei

2018-01-22

Solution processed organic-inorganic hybrid perovskites are emerging as a new generation materials for optoelectronics. However, the electroluminescence is highly limited in light emitting diodes (LED) due to the low exciton binding energy and the great challenge in stability. Here, we demonstrate a super air stable quasi-two dimensional perovskite film employing hydrophobic fluorine-containing organics as barrier layers, which can store in ambient for more than 4 months with no change. The dramatically reduced grain size of the perovskite crystal in contrast to three dimensional (3D) perovskites was achieved. Together with the natural quantum well of quasi-two dimensional perovskite confining the excitons to recombination, the LED exhibited the maximum luminance of 1.2 × 10 3 cd/m 2 and current efficiency up to 0.3 cd/A, which is twenty fold enhancement than that of LED based on 3D analogues under the same condition.

Single Molecule Raman Spectroscopy Under High Pressure

NASA Astrophysics Data System (ADS)

Fu, Yuanxi; Dlott, Dana

2014-06-01

Pressure effects on surface-enhanced Raman scattering spectra of Rhdoamine 6G adsorbed on silver nanoparticle surfaces was studied using a confocal Raman microscope. Colloidal silver nanoparticles were treated with Rhodamine 6G (R6G) and its isotopically substituted partner, R6G-d4. Mixed isotopomers let us identify single-molecule spectra, since multiple-molecule spectra would show vibrational transitions from both species. The nanoparticles were embedded into a poly vinyl alcohol film, and loaded into a diamond anvil cell for the high-pressure Raman scattering measurement. Argon was the pressure medium. Ambient pressure Raman scattering spectra showed few single-molecule spectra. At moderately high pressure ( 1GPa), a surprising effect was observed. The number of sites with observable spectra decreased dramatically, and most of the spectra that could be observed were due to single molecules. The effects of high pressure suppressed the multiple-molecule Raman sites, leaving only the single-molecule sites to be observed.

Reinventing School Finance: Falling Forward

ERIC Educational Resources Information Center

Picus, Lawrence O.; Odden, Allan R.

2011-01-01

States and school districts are facing unprecedented financial pressure due to the continued poor performance of the United States's economy. Dramatic shortfalls in funding due to reduced tax collections were held off for 2 years thanks to federal stimulus funds, but with these revenues already consumed and little likelihood of more in the near…

Plasma immersion ion implantation of polyurethane shape memory polymer: Surface properties and protein immobilization

NASA Astrophysics Data System (ADS)

Cheng, Xinying; Kondyurin, Alexey; Bao, Shisan; Bilek, Marcela M. M.; Ye, Lin

2017-09-01

Polyurethane-type shape memory polymers (SMPU) are promising biomedical implant materials due to their ability to recover to a predetermined shape from a temporary shape induced by thermal activation close to human body temperature and their advantageous mechanical properties including large recovery strains and low recovery stresses. Plasma Immersion Ion Implantation (PIII) is a surface modification process using energetic ions that generates radicals in polymer surfaces leading to carbonisation and oxidation and the ability to covalently immobilise proteins without the need for wet chemistry. Here we show that PIII treatment of SMPU significantly enhances its bioactivity making SMPU suitable for applications in permanent implantable biomedical devices. Scanning Electron Microscopy (SEM), contact angle measurements, surface energy measurements, attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to characterise the PIII modified surface, including its after treatment aging kinetics and its capability to covalently immobilise protein directly from solution. The results show a substantial improvement in wettability and dramatic changes of surface chemical composition dependent on treatment duration, due to the generation of radicals and subsequent oxidation. The SMPU surface, PIII treated for 200s, achieved a saturated level of covalently immobilized protein indicating that a full monolayer coverage was achieved. We conclude that PIII is a promising and efficient surface modification method to enhance the biocompatibility of SMPU for use in medical applications that demand bioactivity for tissue integration and stability in vivo.

Rotational Synchronization May Enhance Habitability for Circumbinary Planets: Kepler Binary Case Studies

NASA Astrophysics Data System (ADS)

Mason, Paul A.; Zuluaga, Jorge I.; Clark, Joni M.; Cuartas-Restrepo, Pablo A.

2013-09-01

We report a mechanism capable of reducing (or increasing) stellar activity in binary stars, thereby potentially enhancing (or destroying) circumbinary habitability. In single stars, stellar aggression toward planetary atmospheres causes mass-loss, which is especially detrimental for late-type stars, because habitable zones are very close and activity is long lasting. In binaries, tidal rotational breaking reduces magnetic activity, thus reducing harmful levels of X-ray and ultraviolet (XUV) radiation and stellar mass-loss that are able to erode planetary atmospheres. We study this mechanism for all confirmed circumbinary (p-type) planets. We find that main sequence twins provide minimal flux variation and in some cases improved environments if the stars rotationally synchronize within the first Gyr. Solar-like twins, like Kepler 34 and Kepler 35, provide low habitable zone XUV fluxes and stellar wind pressures. These wide, moist, habitable zones may potentially support multiple habitable planets. Solar-type stars with lower mass companions, like Kepler 47, allow for protected planets over a wide range of secondary masses and binary periods. Kepler 38 and related binaries are marginal cases. Kepler 64 and analogs have dramatically reduced stellar aggression due to synchronization of the primary, but are limited by the short lifetime. Kepler 16 appears to be inhospitable to planets due to extreme XUV flux. These results have important implications for estimates of the number of stellar systems containing habitable planets in the Galaxy and allow for the selection of binaries suitable for follow-up searches for habitable planets.

Enhanced freight sketch planning tool for assessing multimodal investment strategies.

DOT National Transportation Integrated Search

2006-09-01

In recent years, there have been dramatic changes in the volume and movement of freight within the : US and internationally. Traditional distribution systems have been replaced by just-in-time driven : processes and freight transportation patterns ha...

Creativity and the Dyslexic Child: A Classroom View.

ERIC Educational Resources Information Center

Burrows, Dian; Wolf, Beverly

1983-01-01

Multisensory techniques can be used to provide opportunities for creative expression for children with specific language disabilities. Dramatics, art, movement activities, music, poetry, and dancing can help meet the children's emotional needs while also enhancing their self-concepts. (CL)

A dynamical systems model for combinatorial cancer therapy enhances oncolytic adenovirus efficacy by MEK-inhibition.

PubMed

Bagheri, Neda; Shiina, Marisa; Lauffenburger, Douglas A; Korn, W Michael

2011-02-01

Oncolytic adenoviruses, such as ONYX-015, have been tested in clinical trials for currently untreatable tumors, but have yet to demonstrate adequate therapeutic efficacy. The extent to which viruses infect targeted cells determines the efficacy of this approach but many tumors down-regulate the Coxsackievirus and Adenovirus Receptor (CAR), rendering them less susceptible to infection. Disrupting MAPK pathway signaling by pharmacological inhibition of MEK up-regulates CAR expression, offering possible enhanced adenovirus infection. MEK inhibition, however, interferes with adenovirus replication due to resulting G1-phase cell cycle arrest. Therefore, enhanced efficacy will depend on treatment protocols that productively balance these competing effects. Predictive understanding of how to attain and enhance therapeutic efficacy of combinatorial treatment is difficult since the effects of MEK inhibitors, in conjunction with adenovirus/cell interactions, are complex nonlinear dynamic processes. We investigated combinatorial treatment strategies using a mathematical model that predicts the impact of MEK inhibition on tumor cell proliferation, ONYX-015 infection, and oncolysis. Specifically, we fit a nonlinear differential equation system to dedicated experimental data and analyzed the resulting simulations for favorable treatment strategies. Simulations predicted enhanced combinatorial therapy when both treatments were applied simultaneously; we successfully validated these predictions in an ensuing explicit test study. Further analysis revealed that a CAR-independent mechanism may be responsible for amplified virus production and cell death. We conclude that integrated computational and experimental analysis of combinatorial therapy provides a useful means to identify treatment/infection protocols that yield clinically significant oncolysis. Enhanced oncolytic therapy has the potential to dramatically improve non-surgical cancer treatment, especially in locally advanced or metastatic cases where treatment options remain limited.

The high mobility group protein 1 enhances binding of the estrogen receptor DNA binding domain to the estrogen response element.

PubMed

Romine, L E; Wood, J R; Lamia, L A; Prendergast, P; Edwards, D P; Nardulli, A M

1998-05-01

We have examined the ability of the high-mobility group protein 1 (HMG1) to alter binding of the estrogen receptor DNA-binding domain (DBD) to the estrogen response element (ERE). HMG1 dramatically enhanced binding of purified, bacterially expressed DBD to the consensus vitellogenin A2 ERE in a dose-dependent manner. The ability of HMG1 to stabilize the DBD-ERE complex resulted in part from a decrease in the dissociation rate of the DBD from the ERE. Antibody supershift experiments demonstrated that HMG1 was also capable of forming a ternary complex with the ERE-bound DBD in the presence of HMG1-specific antibody. HMG1 did not substantially affect DBD-ERE contacts as assessed by methylation interference assays, nor did it alter the ability of the DBD to induce distortion in ERE-containing DNA fragments. Because HMG1 dramatically enhanced estrogen receptor DBD binding to the ERE, and the DBD is the most highly conserved region among the nuclear receptor superfamily members, HMG1 may function to enhance binding of other nuclear receptors to their respective response elements and act in concert with coactivator proteins to regulate expression of hormone-responsive genes.

Strain-rate dependence of ramp-wave evolution and strength in tantalum

DOE PAGES

Lane, J. Matthew D.; Foiles, Stephen M.; Lim, Hojun; ...

2016-08-25

We have conducted molecular dynamics (MD) simulations of quasi-isentropic ramp-wave compression to very high pressures over a range of strain rates from 10 11 down to 10 8 1/s. Using scaling methods, we collapse wave profiles from various strain rates to a master profile curve, which shows deviations when material response is strain-rate dependent. Thus, we can show with precision where, and how, strain-rate dependence affects the ramp wave. We find that strain rate affects the stress-strain material response most dramatically at strains below 20%, and that above 30% strain the material response is largely independent of strain rate. Wemore » show good overall agreement with experimental stress-strain curves up to approximately 30% strain, above which simulated response is somewhat too stiff. We postulate that this could be due to our interatomic potential or to differences in grain structure and/or size between simulation and experiment. Strength is directly measured from per-atom stress tensor and shows significantly enhanced elastic response at the highest strain rates. As a result, this enhanced elastic response is less pronounced at higher pressures and at lower strain rates.« less

Characteristics of membrane fouling in submerged membrane bioreactor under sub-critical flux operation.

PubMed

Su, Y C; Huang, C P; Pan, Jill R; Lee, H C

2008-01-01

Recently, the membrane bioreactor (MBR) process has become one of the novel technologies to enhance the performance of biological treatment of wastewater. Membrane bioreactor process uses the membrane unit to replace a sediment tank, and this can greatly enhance treatment performance. However, membrane fouling in MBR restricts its widespread application because it leads to permeate flux decline, making more frequent membrane cleaning and replacement necessary, which then increases operating and maintenance costs. This study investigated the sludge characteristics in membrane fouling under sub-critical flux operation and also assessed the effect of shear stress on membrane fouling. Membrane fouling was slow under sub-critical flux operation. However, as filamentous microbes became dominant in the reactor, membrane fouling increased dramatically due to the increased viscosity and polysaccharides. A close link was found between membrane fouling and the amount of polysaccharides in soluble EPS. The predominant resistance was the cake resistance which could be minimized by increasing the shear stress. However, the resistance of colloids and solutes was not apparently reduced by increasing shear stress. Therefore, smaller particles such as macromolecules (e.g. polysaccharides) may play an important role in membrane fouling under sub-critical flux operation.

Relative quantum yield of I-asterisk(2P1/2) in the tunable laser UV photodissociation of i-C3F7I and n-C3F7I - Effect of temperature and exciplex emission

NASA Technical Reports Server (NTRS)

Smedley, J. E.; Leone, S. R.

1983-01-01

Wavelength-specific relative quantum yields of metastable I from pulsed laser photodissociation of i-C3F7I and n-C3F7I in the range 265-336 nm are determined by measuring the time-resolved infrared emission from the atomic I(P-2(1/2) P-2(3/2) transition. It is shown that although this yield appears to be unity from 265 to 298 nm, it decreases dramatically at longer wavelengths. Values are also reported for the enhancement of emission from metastable I due to exciplex formation at several temperatures. The exciplex formation emission increases linearly with parent gas pressure, but decreases with increasing temperature. Absorption spectra of i- and n-C3F7I between 303 and 497 K are presented, and the effect of temperature on the quantum yields at selected wavelengths greater than 300 nm, where increasing the temperature enhances the absorption considerably, are given. The results are discussed in regard to the development of solar-pumped iodine lasers.

Genetic engineering of novel bluer-colored chrysanthemums produced by accumulation of delphinidin-based anthocyanins.

PubMed

Noda, Naonobu; Aida, Ryutaro; Kishimoto, Sanae; Ishiguro, Kanako; Fukuchi-Mizutani, Masako; Tanaka, Yoshikazu; Ohmiya, Akemi

2013-10-01

Chrysanthemums (Chrysanthemum morifolium Ramat.) have no purple-, violet- or blue-flowered cultivars because they lack delphinidin-based anthocyanins. This deficiency is due to the absence of the flavonoid 3',5'-hydroxylase gene (F3'5'H), which encodes the key enzyme for delphinidin biosynthesis. In F3'5'H-transformed chrysanthemums, unpredictable and unstable expression levels have hampered successful production of delphinidin and reduced desired changes in flower color. With the aim of achieving delphinidin production in chrysanthemum petals, we found that anthocyanin biosynthetic gene promoters combined with a translational enhancer increased expression of some F3'5'H genes and accompanying delphinidin-based anthocyanin accumulation in transgenic chrysanthemums. Dramatic accumulation of delphinidin (up to 95%) was achieved by simple overexpression of Campanula F3'5'H controlled by a petal-specific flavanone 3-hydroxylase promoter from chrysanthemum combined with the 5'-untranslated region of the alcohol dehydrogenase gene as a translational enhancer. The flower colors of transgenic lines producing delphinidin-based anthocyanins changed from a red-purple to a purple-violet hue in the Royal Horticultural Society Colour Charts. This result represents a promising step toward molecular breeding of blue chrysanthemums.

Interaction between the extracellular matrix and lymphatics - consequences for lymphangiogenesis and lymphatic function

PubMed Central

Wiig, Helge; Keskin, Doruk; Kalluri, Raghu

2014-01-01

The lymphatic system is important for body fluid balance as well as immunological surveillance. Due to the identification of new molecular markers during the last decade, there has been a recent dramatic increase in our knowledge on the molecular mechanisms involved in lymphatic vessel growth (lymphangiogenesis) and lymphatic function. Here we review data showing that although it is often overlooked, the extracellular matrix plays an important role in the generation of new lymphatic vessels as a response to physiological and pathological stimuli. Extracellular matrix-lymphatic interactions as well as biophysical characteristics of the stroma have consequences for tumor formation, growth and metastasis. During the recent years, anti-lymphangiogenesis has emerged as an additional therapeutic modality to the clinically applied anti-angiogenesis strategy. Oppositely, enhancement of lymphangiogenesis in situations of lymph accumulation is seen as a promising strategy to a set of conditions where few therapeutic avenues are available. Knowledge on the interaction between the extracellular matrix and the lymphatics may enhance our understanding of the underlying mechanisms and may ultimately lead to better therapies for conditions where reduced or increased lymphatic function is the therapeutic target PMID:20727409

Ultrasound enhanced thrombolysis: Clinical evidence

NASA Astrophysics Data System (ADS)

Alexandrov, Andrei V.

2005-04-01

Phase II CLOTBUST randomized clinical trial (Houston, Barcelona, Edmonton, Calgary) evaluated patients with acute ischemic stroke due to intracranial occlusion and treated with intravenous tissue plasminogen activator (TPA) within 3 h of symptom onset. Randomization: monitoring with pulsed wave 2 MHz transcranial Doppler (TCD) (Target) or placebo monitoring (Control). Safety: symptomatic bleeding to the brain (sICH). Primary end-point: complete recanalization on TCD or dramatic clinical recovery by the total NIHSS score <3, or improvement by >10 NIHSS points within 2 hours after TPA bolus. All projected 126 patients were randomized 1:1 to target (median NIHSS 16) or control (NIHSS 17). sICH: 4.8% Target, 4.8% Controls. Primary end-point was achieved by 31 (49%, Target) versus 19 (30%, Control), p<0.03. At 3 months, 22 (42% Target) and 14 (29% Control) patients achieved favorable outcomes. Continuous TCD monitoring of intracranial occlusion safely augments TPA-induced arterial recanalization, and 2 MHz diagnostic ultrasound has a positive biological activity that aids systemic thrombolytic therapy. For the first time in clinical medicine, the CLOTBUST trial provides the evidence that ultrasound enhances thrombolytic activity of a drug in humans thereby confirming intense multi-disciplinary experimental research conducted worldwide for the past 30 years.

Specific disruption of Lnk in murine endothelial progenitor cells promotes dermal wound healing via enhanced vasculogenesis, activation of myofibroblasts, and suppression of inflammatory cell recruitment.

PubMed

Lee, Jun Hee; Ji, Seung Taek; Kim, Jaeho; Takaki, Satoshi; Asahara, Takayuki; Hong, Young-Joon; Kwon, Sang-Mo

2016-10-28

Although endothelial progenitor cells (EPCs) contribute to wound repair by promoting neovascularization, the mechanism of EPC-mediated wound healing remains poorly understood due to the lack of pivotal molecular targets of dermal wound repair. We found that genetic targeting of the Lnk gene in EPCs dramatically enhances the vasculogenic potential including cell proliferation, migration, and tubule-like formation as well as accelerates in vivo wound healing, with a reduction in fibrotic tissue and improved neovascularization via significant suppression of inflammatory cell recruitment. When injected into wound sites, Lnk -/- EPCs gave rise to a significant number of new vessels, with remarkably increased survival of transplanted cells and decreased recruitment of cytotoxic T cells, macrophages, and neutrophils, but caused activation of fibroblasts in the wound-remodeling phase. Notably, in a mouse model of type I diabetes, transplanted Lnk -/- EPCs induced significantly better wound healing than Lnk +/+ EPCs did. The specific targeting of Lnk may be a promising EPC-based therapeutic strategy for dermal wound healing via improvement of neovascularization but inhibition of excessive inflammation as well as activation of myofibroblasts during dermal tissue remodeling.

Magnetic Enrichment of Dendritic Cell Vaccine in Lymph Node with Fluorescent-Magnetic Nanoparticles Enhanced Cancer Immunotherapy

PubMed Central

Jin, Honglin; Qian, Yuan; Dai, Yanfeng; Qiao, Sha; Huang, Chuan; Lu, Lisen; Luo, Qingming; Chen, Jing; Zhang, Zhihong

2016-01-01

Dendritic cell (DC) migration to the lymph node is a key component of DC-based immunotherapy. However, the DC homing rate to the lymphoid tissues is poor, thus hindering the DC-mediated activation of antigen-specific T cells. Here, we developed a system using fluorescent magnetic nanoparticles (α-AP-fmNPs; loaded with antigen peptide, iron oxide nanoparticles, and indocyanine green) in combination with magnetic pull force (MPF) to successfully manipulate DC migration in vitro and in vivo. α-AP-fmNPs endowed DCs with MPF-responsiveness, antigen presentation, and simultaneous optical and magnetic resonance imaging detectability. We showed for the first time that α-AP-fmNP-loaded DCs were sensitive to MPF, and their migration efficiency could be dramatically improved both in vitro and in vivo through MPF treatment. Due to the enhanced migration of DCs, MPF treatment significantly augmented antitumor efficacy of the nanoparticle-loaded DCs. Therefore, we have developed a biocompatible approach with which to improve the homing efficiency of DCs and subsequent anti-tumor efficacy, and track their migration by multi-modality imaging, with great potential applications for DC-based cancer immunotherapy. PMID:27698936

A new class of high-contrast Fe(II) selective fluorescent probes based on spirocyclized scaffolds for visualization of intracellular labile iron delivered by transferrin.

PubMed

Niwa, Masato; Hirayama, Tasuku; Okuda, Kensuke; Nagasawa, Hideko

2014-09-14

Iron is an essential metal nutrient that plays physiologically and pathologically important roles in biological systems. However, studies on the trafficking, storage, and functions of iron itself in living samples have remained challenging due to the lack of efficient methods for monitoring labile intracellular iron. Herein, we report a new class of Fe(2+)-selective fluorescent probes based on the spirocyclization of hydroxymethylrhodamine and hydroxymethylrhodol scaffolds controlled by using our recently established N-oxide chemistry as a Fe(2+)-selective switch of fluorescence response. By suppressing the background signal, the spirocyclization strategy improved the turn-on rate dramatically, and reducing the size of the substituents of the N-oxide group enhanced the reaction rate against Fe(2+), compared with the first generation N-oxide based Fe(2+) probe, RhoNox-1. These new probes showed significant enhancements in the fluorescence signal against not only the exogenously loaded Fe(2+) but also the endogenous Fe(2+) levels. Furthermore, we succeeded in monitoring the accumulation of labile iron in the lysosome induced by transferrin-mediated endocytosis with a turn-on fluorescence response.

Enhancement of the inverted polymer solar cells via ZnO doped with CTAB

NASA Astrophysics Data System (ADS)

Sivashnamugan, Kundan; Guo, Tzung-Fang; Hsu, Yao-Jane; Wen, Ten-Chin

2018-02-01

A facile approach enhancing electron extraction in zinc oxide (ZnO) electron transfer interlayer and improving performance of bulk-heterojunction (BHJ) polymer solar cells (PSCs) by adding cetyltrimethylammonium bromide (CTAB) into sol-gel ZnO precursor solution was demonstrated in this work. The power conversion efficiency (PCE) has a 24.1% increment after modification. Our results show that CTAB can dramatically influence optical, electrical and morphological properties of ZnO electron transfer layer, and work as effective additive to enhance the performance of bulk- heterojunction polymer solar cells.

Making the Constitution Meaningful.

ERIC Educational Resources Information Center

Pelow, Randall A.

1989-01-01

Describes learning activities based on the U.S. Constitution that enhance higher level thinking skills in elementary students. One activity proposes a hypothetical constitutional amendment banning Saturday cartoons; a second taxes children's earnings; and other activities focus on dramatizing events surrounding the Constitutional Convention. (LS)

Ultrafast electrochemical preparation of graphene/CoS nanosheet counter electrodes for efficient dye-sensitized solar cells

DOE PAGES

Zhu, Chongyang; Zhu, Yimei; Min, Huihua; ...

2015-10-05

Utilizing inexpensive, high-efficiency counter electrodes (CEs) to replace the traditional platinum counterparts in dye-sensitized solar cells (DSSCs) is worthwhile. In this paper, we detail how we synchronously prepared composite CEs of CoS nanosheet arrays and reduced graphene oxide (rGO) layers for the first time via a low temperature, ultrafast one-step electrochemical strategy. With this approach, the whole fabrication process of the composite CEs was only a small percentage of the average time (~15 hours) using other methods. The DSSC assembled with the rGO–CoS composite CE achieved an enhanced power conversion efficiency (PCE) of 8.34%, which is dramatically higher than 6.27%more » of pure CoS CE-based DSSC and even exceeds 7.50% of Pt CE-based DSSC. The outstanding PCE breakthrough is undoubtedly attributed to the enhancement in electrocatalytic ability of the rGO–CoS composite CE due to the incorporation of highly conducting rGO layers and the GO layers-induced growth of CoS nanosheet arrays with higher density and larger surface area. Therefore, lower charge-transfer resistance and higher exchange current density can be achieved as corroborated by the electrochemical impedance spectra (EIS) and Tafel polarization curves (TPCs). As a result, further experiments also proved that the electrochemical strategy exhibited its universality of fabricating other graphene-enhanced chalcogenide functional composite films.« less

Near-infrared fluorescence imaging using organic dye nanoparticles.

PubMed

Yu, Jia; Zhang, Xiujuan; Hao, Xiaojun; Zhang, Xiaohong; Zhou, Mengjiao; Lee, Chun-Sing; Chen, Xianfeng

2014-03-01

Near-infrared (NIR) fluorescence imaging in the 700-1000 nm wavelength range has been very attractive for early detection of cancers. Conventional NIR dyes often suffer from limitation of low brightness due to self-quenching, insufficient photo- and bioenvironmental stability, and small Stokes shift. Herein, we present a strategy of using small-molecule organic dye nanoparticles (ONPs) to encapsulate NIR dyes to enable efficient fluorescence resonance energy transfer to obtain NIR probes with remarkably enhanced performance for in vitro and in vivo imaging. In our design, host ONPs are used as not only carriers to trap and stabilize NIR dyes, but also light-harvesting agent to transfer energy to NIR dyes to enhance their brightness. In comparison with pure NIR dyes, our organic dye nanoparticles possess almost 50-fold increased brightness, large Stokes shifts (∼250 nm) and dramatically enhanced photostability. With surface modification, these NIR-emissive organic nanoparticles have water-dispersity and size- and fluorescence- stability over pH values from 2 to 10 for almost 60 days. With these superior advantages, these NIR-emissive organic nanoparticles can be used for highly efficient folic-acid aided specific targeting in vivo and ex vivo cellular imaging. Finally, during in vivo imaging, the nanoparticles show negligible toxicity. Overall, the results clearly display a potential application of using the NIR-emissive organic nanoparticles for in vitro and in vivo imaging. Copyright © 2014 Elsevier Ltd. All rights reserved.

Enhanced superconducting transition temperature in hyper-interlayer-expanded FeSe despite the suppressed electronic nematic order and spin fluctuations

NASA Astrophysics Data System (ADS)

Hrovat, Matevž Majcen; Jeglič, Peter; Klanjšek, Martin; Hatakeda, Takehiro; Noji, Takashi; Tanabe, Yoichi; Urata, Takahiro; Huynh, Khuong K.; Koike, Yoji; Tanigaki, Katsumi; Arčon, Denis

2015-09-01

The superconducting critical temperature, Tc, of FeSe can be dramatically enhanced by intercalation of a molecular spacer layer. Here we report on a 77Se,7Li , and 1H nuclear magnetic resonance (NMR) study of the powdered hyper-interlayer-expanded Lix(C2H8N2) yFe2 -zSe2 with a nearly optimal Tc=45 K. The absence of any shift in the 7Li and 1H NMR spectra indicates a complete decoupling of interlayer units from the conduction electrons in FeSe layers, whereas nearly temperature-independent 7Li and 1H spin-lattice relaxation rates are consistent with the non-negligible concentration of Fe impurities present in the insulating interlayer space. On the other hand, the strong temperature dependence of 77Se NMR shift and spin-lattice relaxation rate, 1 /77T1 , is attributed to the holelike bands close to the Fermi energy. 1 /77T1 shows no additional anisotropy that would account for the onset of electronic nematic order down to Tc. Similarly, no enhancement in 1 /77T1 due to the spin fluctuations could be found in the normal state. Yet, a characteristic power-law dependence 1 /77T1∝T4.5 still complies with the Cooper pairing mediated by spin fluctuations.

Metabolic clues regarding the enhanced performance of elite endurance athletes from orchiectomy-induced hormonal changes.

PubMed

Atwood, Craig S; Bowen, Richard L

2007-01-01

This article examines the metabolic performance of an elite cyclist, Lance Armstrong, before and after his diagnosis with testicular cancer. Although a champion cyclist in 1-day events prior to his diagnosis of testicular cancer at age 25, he was not a contender in multi-day endurance cycle races such as the 3-week Tour de France. His genetic makeup and physiology (high VO2max, long femur, strong heavy build) coupled with his ambition and motivation enabled him at an early age to become one of the best 1-day cyclists in the world. Following his cancer diagnosis, he underwent a unilateral orchiectomy, brain surgery and four cycles of chemotherapy. After recovering, he returned to cycling and surprisingly excelled in the Tour de France, winning this hardest of endurance events 7 years running. This dramatic transformation from a 1-day to a 3-week endurance champion has led many to query how this is possible, and under the current climate, has led to suggestions of doping as to the answer to this metamorphosis. Physiological tests following his recovery indicated that physiological parameters such as VO2max were not affected by the unilateral orchiectomy and chemotherapy. We propose that his dramatic improvement in recovery between stages, the most important factor in winning multi-day stage races, is due to his unilateral orchiectomy, a procedure that results in permanent changes in serum hormones. These hormonal changes, specifically an increase in gonadotropins (and prolactin) required to maintain serum testosterone levels, alter fuel metabolism; increasing hormone sensitive lipase expression and activity, promoting increased free fatty acid (FFA) mobilization to, and utilization by, muscles, thereby decreasing the requirement to expend limiting glycogen stores before, during and after exercise. Such hormonal changes also have been associated with ketone body production, improvements in muscle repair and haematocrit levels and may facilitate the loss of body weight, thereby increasing power to weight ratio. Taken together, these hormonal changes act to limit glycogen utilization, delay fatigue and enhance recovery thereby allowing for optimal performances on a day-to-day basis. These insights provide the foundation for future studies on the endocrinology of exercise metabolism, and suggest that Lance Armstrong's athletic advantage was not due to drug use.

Investigation of structural and luminescent properties of Ce{sup 3+}/Mn{sup 2+} ions-doped Ca{sub 5}(PO{sub 4}){sub 3}F

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Lei; Fu, Zuoling, E-mail: zlfu@jlu.edu.cn; Wu, Zhijian

Graphical abstract: The structural and luminescent properties FAP: Ce{sup 3+} and FAP: Ce{sup 3+}, Mn{sup 2+} were investigated in detail by the spectral measurement and theoretical calculation. The emission of Ce{sup 3+} is fitted by two Gaussian functions dashed lines in wavenumber to further confirm the Ce{sup 3+} ion simultaneously occupy the 4f and 6h sites Ca{sub 5}(PO{sub 4})F host. - Highlights: • A simple hydrothermal method has been used to prepare Ca{sub 5}(PO{sub 4}){sub 3}F: Ce{sup 3+}, Mn{sup 2+} powders with structural and luminescent analysis. • The emission of Ce{sup 3+} is fitted by two Gaussian functions to confirmmore » the Ce{sup 3+} ion simultaneously to occupy the 4f and 6h sites in Ca{sub 5}(PO{sub 4}){sub 3}F host. • Due to an efficient energy transfer, the existence of Ce{sup 3+} (sensitizer) can dramatically enhance the green emission of Mn{sup 2+} (activator) in co-doped samples. - Abstract: Ce{sup 3+}/Mn{sup 2+} ions-doped oxyapatite calcium fluorapatite [Ca{sub 5}(PO{sub 4}){sub 3}F, FAP] has been successfully synthesized by a facile one-step hydrothermal method. The luminescent properties of Ce{sup 3+}- and Ce{sup 3+}/Mn{sup 2+}- activated FAP phosphors were investigated using the photoluminescence (PL) and photoluminescence excitation (PLE) spectra. The emission of Ce{sup 3+} was fitted by two Gaussian functions with dashed lines in wavenumber to confirm the Ce{sup 3+} ion simultaneously to occupy the 4f and 6h sites in Ca{sub 5}(PO{sub 4}){sub 3}F host, which was consistent with the calculated results of crystal field based on chemical bond theory. In addition, the existence of Ce{sup 3+} (sensitizer) can dramatically enhance the green emission of Mn{sup 2+} (activator) in Ce{sup 3+}/Mn{sup 2+} ions co-doped samples due to an efficient energy transfer from Ce{sup 3+} to Mn{sup 2+}. All of these results could help us understand the site assignments and optical properties of the rare earth ions doped in hexagonal Ca{sub 5}(PO{sub 4}){sub 3}F.« less

The influence of hydrodynamic slip on the electrophoretic mobility of a spherical colloidal particle

NASA Astrophysics Data System (ADS)

Khair, Aditya S.; Squires, Todd M.

2009-04-01

Recent theoretical studies have suggested a significant enhancement in electro-osmotic flows over hydrodynamically slipping surfaces, and experiments have indeed measured O(1) enhancements. In this paper, we investigate whether an equivalent effect occurs in the electrophoretic motion of a colloidal particle whose surface exhibits hydrodynamic slip. To this end, we compute the electrophoretic mobility of a uniformly charged spherical particle with slip length λ as a function of the zeta (or surface) potential of the particle ζ and diffuse-layer thickness κ-1. In the case of a thick diffuse layer, κa ≪1 (where a is the particle size), simple arguments show that slip does lead to an O(1) enhancement in the mobility, owing to the reduced viscous drag on the particle. On the other hand, for a thin-diffuse layer κa ≫1, the situation is more complicated. A detailed asymptotic analysis, following the method of O'Brien [J. Colloid Interface Sci. 92, 204 (1983)], reveals that an O(κλ) increase in the mobility occurs at low-to-moderate zeta potentials (with ζ measured on the scale of thermal voltage kBT /e≈25 mV). However, as ζ is further increased, the mobility decreases and ultimately becomes independent of the slip length—the enhancement is lost—which is due to the importance of nonuniform surface conduction within the thin-diffuse layer, at large ζ and large, but finite, κa. Our asymptotic calculations for thick and thin-diffuse layers are corroborated and bridged by computation of the mobility from the numerical solution of the full electrokinetic equations (using the method of O'Brien and White [J. Chem. Soc., Faraday Trans. 2 74, 1607 (1978)]). In summary, then, we demonstrate that hydrodynamic slip can indeed produce an enhancement in the electrophoretic mobility; however, such enhancements will not be as dramatic as the previously studied κa →∞ limit would suggest. Importantly, this conclusion applies not only to electrophoresis but also to electro-osmosis over highly charged surfaces, wherein any inhomogeneities (e.g., due to curvature, roughness, charge patterning, or a variation in slip length) will drive nonuniform surface conduction, which prevents the significant slip-driven flow enhancements predicted for a uniform highly charged surface.

Effective cancer laser-therapy design through the integration of nanotechnology and computational treatment planning models

NASA Astrophysics Data System (ADS)

Fisher, Jessica W.; Rylander, Marissa Nichole

2008-02-01

Laser therapies can provide a minimally invasive treatment alternative to surgical resection of tumors. However, the effectiveness of these therapies is limited due to nonspecific heating of target tissue which often leads to healthy tissue injury and extended treatment durations. These therapies can be further compromised due to heat shock protein (HSP) induction in tumor regions where non-lethal temperature elevation occurs, thereby imparting enhanced tumor cell viability and resistance to subsequent chemotherapy and radiation treatments. Introducing multi-walled nanotubes (MWNT) into target tissue prior to laser irradiation increases heating selectivity permitting more precise thermal energy delivery to the tumor region and enhances thermal deposition thereby increasing tumor injury and reducing HSP expression induction. This study investigated the impact of MWNT inclusion in untreated and laser irradiated monolayer cell culture and cell phantom model. Cell viability remained high for all samples with MWNT inclusion and cells integrated into alginate phantoms, demonstrating the non-toxic nature of both MWNTs and alginate phantom models. Following, laser irradiation samples with MWNT inclusion exhibited dramatic temperature elevations and decreased cell viability compared to samples without MWNT. In the cell monolayer studies, laser irradiation of samples with MWNT inclusion experienced up-regulated HSP27, 70 and 90 expression as compared to laser only or untreated samples due to greater temperature increases albeit below the threshold for cell death. Further tuning of laser parameters will permit effective cell killing and down-regulation of HSP. Due to optimal tuning of laser parameters and inclusion of MWNT in phantom models, extensive temperature elevations and cell death occurred, demonstrating MWNT-mediated laser therapy as a viable therapy option when parameters are optimized. In conclusion, MWNT-mediated laser therapies show great promise for effective tumor destruction, but require determination of appropriate MWNT characteristics and laser parameters for maximum tumor destruction.

Mutations that alter the equilibrium between open and closed conformations of Escherichia coli maltose-binding protein impede its ability to enhance the solubility of passenger proteins

PubMed Central

Nallamsetty, Sreedevi; Waugh, David S.

2007-01-01

Certain highly soluble proteins, such as Escherichia coli maltose-binding protein (MBP), have the ability to enhance the solubility of their fusion partners, making them attractive vehicles for the production of recombinant proteins, yet the mechanism of solubility enhancement remains poorly understood. Here, we report that the solubility-enhancing properties of MBP are dramatically affected by amino acid substitutions that alter the equilibrium between its “open” and “closed” conformations. Our findings indicate that the solubility-enhancing activity of MBP is mediated by its open conformation and point to a likely role for the ligand-binding cleft in the mechanism of solubility enhancement. PMID:17964542

Strategies for data management engagement.

PubMed

Charbonneau, Deborah H

2013-01-01

The research landscape is growing dramatically, and librarians are examining new roles, services, and types of collaborations to support data-intensive research. This column describes curricular enhancements at one School of Library and Information Science in the United States. Several key areas of data management in which health sciences librarians may wish to build or enhance their skills are outlined. Possible roles and opportunities for health sciences librarians to strategically engage in data management initiatives are also presented.

Fluorescence enhancement by Au nanostructures: nanoshells and nanorods.

PubMed

Bardhan, Rizia; Grady, Nathaniel K; Cole, Joseph R; Joshi, Amit; Halas, Naomi J

2009-03-24

Metallic nanoparticles influence the quantum yield and lifetime of adjacent fluorophores in a manner dependent on the properties of the nanostructure. Here we directly compare the fluorescence enhancement of the near-infrared fluorophore IR800 by Au nanoshells (NSs) and Au nanorods (NRs), where human serum albumin (HSA) serves as a spacer layer between the nanoparticle and the fluorophore. Our measurements reveal that the quantum yield of IR800 is enhanced from approximately 7% as an isolated fluorophore to 86% in a NSs-HSA-IR800 complex and 74% in a NRs-HSA-IR800 complex. This dramatic increase in fluorescence shows tremendous potential for contrast enhancement in fluorescence-based bioimaging.

Enlightening Advantages of Cooperative Learning

ERIC Educational Resources Information Center

Faryadi, Qais

2007-01-01

This appraisal discusses the notion that cooperative learning enhances learners' emotional and social performance. It also observes the perception that cooperative learning dramatically improves students' academic accomplishment. This review also examines the definition of cooperative learning and attempts to define it through the lens of renowned…

Teaching with Transmedia

ERIC Educational Resources Information Center

Pence, Harry E.

2012-01-01

The media environment is currently being dramatically changed by social networking, mobile computing, augmented reality, and transmedia. Of these four, transmedia is probably the least familiar to most educators. Transmedia enhances a central story idea with a variety of media components that provide additional information, give increased…

Individual Events Judging Philosophy.

ERIC Educational Resources Information Center

Cronn-Mills, Daniel

Understanding communication (of which individual events is a part) requires a triangle among theory-practice-criticism, and any missing component dramatically hinders understanding and ability. Students compete in, and judges judge, forensics to better enhance communication understanding and abilities. The process of oral interpretation requires a…

The Brain-Compatible Curriculum.

ERIC Educational Resources Information Center

Westwater, Anne; Wolfe, Pat

2000-01-01

Demonstrates how teachers can make instruction more meaningful by linking new subject matter to students' previous experiences and by using community resources to create exciting new learning experiences. If the content is rigorous and relevant, debates, storytelling, the arts, graphic organizers, and mnemonics can dramatically enhance student…

Dramatically Enhanced Spin Dynamo with Plasmonic Diabolo Cavity.

PubMed

Gou, Peng; Qian, Jie; Xi, Fuchun; Zou, Yuexin; Cao, Jun; Yu, Haochi; Zhao, Ziyi; Yang, Le; Xu, Jie; Wang, Hengliang; Zhang, Lijian; An, Zhenghua

2017-07-13

The applications of spin dynamos, which could potentially power complex nanoscopic devices, have so far been limited owing to their extremely low energy conversion efficiencies. Here, we present a unique plasmonic diabolo cavity (PDC) that dramatically improves the spin rectification signal (enhancement of more than three orders of magnitude) under microwave excitation; further, it enables an energy conversion efficiency of up to ~0.69 mV/mW, compared with ~0.27 μV/mW without a PDC. This remarkable improvement arises from the simultaneous enhancement of the microwave electric field (~13-fold) and the magnetic field (~195-fold), which cooperate in the spin precession process generates photovoltage (PV) efficiently under ferromagnetic resonance (FMR) conditions. The interplay of the microwave electromagnetic resonance and the ferromagnetic resonance originates from a hybridized mode based on the plasmonic resonance of the diabolo structure and Fabry-Perot-like modes in the PDC. Our work sheds light on how more efficient spin dynamo devices for practical applications could be realized and paves the way for future studies utilizing both artificial and natural magnetism for applications in many disciplines, such as for the design of future efficient wireless energy conversion devices, high frequent resonant spintronic devices, and magnonic metamaterials.

Biomass burning emissions of trace gases and particles in marine air at Cape Grim, Tasmania

NASA Astrophysics Data System (ADS)

Lawson, S. J.; Keywood, M. D.; Galbally, I. E.; Gras, J. L.; Cainey, J. M.; Cope, M. E.; Krummel, P. B.; Fraser, P. J.; Steele, L. P.; Bentley, S. T.; Meyer, C. P.; Ristovski, Z.; Goldstein, A. H.

2015-12-01

Biomass burning (BB) plumes were measured at the Cape Grim Baseline Air Pollution Station during the 2006 Precursors to Particles campaign, when emissions from a fire on nearby Robbins Island impacted the station. Measurements made included non-methane organic compounds (NMOCs) (PTR-MS), particle number size distribution, condensation nuclei (CN) > 3 nm, black carbon (BC) concentration, cloud condensation nuclei (CCN) number, ozone (O3), methane (CH4), carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), nitrous oxide (N2O), halocarbons and meteorology. During the first plume strike event (BB1), a 4 h enhancement of CO (max ~ 2100 ppb), BC (~ 1400 ng m-3) and particles > 3 nm (~ 13 000 cm-3) with dominant particle mode of 120 nm were observed overnight. A wind direction change lead to a dramatic reduction in BB tracers and a drop in the dominant particle mode to 50 nm. The dominant mode increased in size to 80 nm over 5 h in calm sunny conditions, accompanied by an increase in ozone. Due to an enhancement in BC but not CO during particle growth, the presence of BB emissions during this period could not be confirmed. The ability of particles > 80 nm (CN80) to act as CCN at 0.5 % supersaturation was investigated. The ΔCCN / ΔCN80 ratio was lowest during the fresh BB plume (56 ± 8 %), higher during the particle growth period (77 ± 4 %) and higher still (104 ± 3 %) in background marine air. Particle size distributions indicate that changes to particle chemical composition, rather than particle size, are driving these changes. Hourly average CCN during both BB events were between 2000 and 5000 CCN cm-3, which were enhanced above typical background levels by a factor of 6-34, highlighting the dramatic impact BB plumes can have on CCN number in clean marine regions. During the 29 h of the second plume strike event (BB2) CO, BC and a range of NMOCs including acetonitrile and hydrogen cyanide (HCN) were clearly enhanced and some enhancements in O3 were observed (ΔO3 / ΔCO 0.001-0.074). A short-lived increase in NMOCs by a factor of 10 corresponded with a large CO enhancement, an increase of the NMOC / CO emission ratio (ER) by a factor of 2-4 and a halving of the BC / CO ratio. Rainfall on Robbins Island was observed by radar during this period which likely resulted in a lower fire combustion efficiency, and higher emission of compounds associated with smouldering. This highlights the importance of relatively minor meteorological events on BB emission ratios. Emission factors (EFs) were derived for a range of trace gases, some never before reported for Australian fires, (including hydrogen, phenol and toluene) using the carbon mass balance method. This provides a unique set of EFs for Australian coastal heathland fires. Methyl halide EFs were higher than EFs reported from other studies in Australia and the Northern Hemisphere which is likely due to high halogen content in vegetation on Robbins Island. This work demonstrates the substantial impact that BB plumes can have on the composition of marine air, and the significant changes that can occur as the plume interacts with terrestrial, aged urban and marine emission sources.

Application of a Salt Coformer in a Co-Amorphous Drug System Dramatically Enhances the Glass Transition Temperature: A Case Study of the Ternary System Carbamazepine, Citric Acid, and l-Arginine.

PubMed

Ueda, Hiroshi; Wu, Wenqi; Löbmann, Korbinian; Grohganz, Holger; Müllertz, Anette; Rades, Thomas

2018-05-07

The use of co-amorphous systems containing a combination of low molecular weight drugs and excipients is a relatively new technology in the pharmaceutical field to improve the solubility of poorly water-soluble drugs. However, some co-amorphous systems show a lower glass transition temperature ( T g ) than many of their polymeric solid dispersion counterparts. In this study, we aimed at designing a stable co-amorphous system with an elevated T g . Carbamazepine (CBM) and citric acid (CA) were employed as the model drug and the coformer, respectively. co-amorphous CBM-CA at a 1:1 molar ratio was formed by ball milling, but a transition from the glassy to the supercooled melt state was observed under ambient conditions, due to the relatively low T g of 38.8 °C of the co-amorphous system and moisture absorption. To improve the T g of the coformer, salt formation of a combination of l-arginine (ARG) with CA was studied. First, ball milling of CA-ARG at molar ratios of 1:1, 1:2, and 1:3 forming co-amorphous systems was performed and led to a dramatic enhancement of the T g , depending on the CA-ARG ratio. Salt formation between CA and ARG was observed by infrared spectroscopy. Next, ball milling of CBM-CA-ARG at molar ratios of 1:1:1, 1:1:2, and 1:1:3 resulted in co-amorphous blends, which had a single T g at 77.8, 105.3, and 127.8 °C, respectively. These ternary co-amorphous samples remained in a solid amorphous form for 2 months at 40 °C. From these results, it can be concluded that blending of the salt coformer with a drug is a promising strategy to design stable co-amorphous formulations.

Targeting the permeability barrier and peptidoglycan recycling pathways to disarm Pseudomonas aeruginosa against the innate immune system

PubMed Central

Moya, Bartolomé; Munar-Bestard, Marta; Zamorano, Laura; Cabot, Gabriel; Blázquez, Jesús; Ayala, Juan A.; Oliver, Antonio

2017-01-01

Antimicrobial resistance is a continuously increasing threat that severely compromises our antibiotic arsenal and causes thousands of deaths due to hospital-acquired infections by pathogens such as Pseudomonas aeruginosa, situation further aggravated by the limited development of new antibiotics. Thus, alternative strategies such as those targeting bacterial resistance mechanisms, virulence or potentiating the activity of our immune system resources are urgently needed. We have recently shown that mutations simultaneously causing the peptidoglycan recycling blockage and the β-lactamase AmpC overexpression impair the virulence of P.aeruginosa. These findings suggested that peptidoglycan metabolism might be a good target not only for fighting antibiotic resistance, but also for the attenuation of virulence and/or potentiation of our innate immune weapons. Here we analyzed the activity of the innate immune elements peptidoglycan recognition proteins (PGRPs) and lysozyme against P. aeruginosa. We show that while lysozyme and PGRPs have a very modest basal effect over P. aeruginosa, their bactericidal activity is dramatically increased in the presence of subinhibitory concentrations of the permeabilizing agent colistin. We also show that the P. aeruginosa lysozyme inhibitors seem to play a very residual protective role even in permeabilizing conditions. In contrast, we demonstrate that, once the permeability barrier is overpassed, the activity of lysozyme and PGRPs is dramatically enhanced when inhibiting key peptidoglycan recycling components (such as the 3 AmpDs, AmpG or NagZ), indicating a decisive protective role for cell-wall recycling and that direct peptidoglycan-binding supports, at least partially, the activity of these enzymes. Finally, we show that recycling blockade when occurring simultaneously with AmpC overexpression determines a further decrease in the resistance against PGRP2 and lysozyme, linked to quantitative changes in the cell-wall. Thus, our results help to delineate new strategies against P. aeruginosa infections, simultaneously targeting β–lactam resistance, cell-wall metabolism and virulence, ultimately enhancing the activity of our innate immune weapons. PMID:28742861

In Situ Determination of Bisphenol A in Beverage Using a Molybdenum Selenide/Reduced Graphene Oxide Nanoparticle Composite Modified Glassy Carbon Electrode.

PubMed

Shi, Rongguang; Liang, Jing; Zhao, Zongshan; Liu, Yi; Liu, Aifeng

2018-05-22

Due to the endocrine disturbing effects of bisphenol A (BPA) on organisms, rapid detection has become one of the most important techniques for monitoring its levels in the aqueous solutions associated with plastics and human beings. In this paper, a glassy carbon electrode (GCE) modified with molybdenum selenide/reduced graphene oxide (MoSe₂/rGO) was fabricated for in situ determination of bisphenol A in several beverages. The surface area of the electrode dramatically increases due to the existence of ultra-thin nanosheets in a flower-like structure of MoSe₂. Adding phosphotungstic acid in the electrolyte can significantly enhance the repeatability (RSD = 0.4%) and reproducibility (RSD = 2.2%) of the electrode. Under the optimized condition (pH = 6.5), the linear range of BPA was from 0.1 μM⁻100 μM and the detection limit was 0.015 μM (S/ N = 3). When using the as-prepared electrode for analyzing BPA in beverage samples without any pretreatments, the recoveries ranged from 98⁻107%, and the concentrations were from below the detection limit to 1.7 μM, indicating its potential prospect for routine analysis of BPA.

Mixing and Flow-field Characteristics of Strongly-forced Transitional / Turbulent Jets and Jet Flames

NASA Astrophysics Data System (ADS)

Lakshminarasimhan, Krishna

2005-11-01

Strong pulsations of the fuel flow rate have previously been shown to dramatically alter the flame length and luminosity of nonpremixed jet flames. The mechanisms responsible for such changes are explored experimentally in nonreacting and reacting strongly pulsed jets by using cinematographic PIV and acetone PLIF. The large amplitude forcing was obtained by pulsing the flow using a solenoid valve at the organ-pipe resonance frequency of the fuel delivery tube. The velocity fluctuations in the flow produced by the resonant pulsing of the jet can reach to about 8 times that of the mean flow. The jet characteristics were studied for Reynolds numbers based on mean flow velocity ranging between 800 and 2400. The PIV shows that with strong pulsations the jet exhibits significant reverse flow into the fuel delivery tube and an increase in turbulence in the near-field region. The acetone PLIF imaging was performed inside and outside the fuel tube in order to study the effects of pulsations on the mixing. These measurements showed significant in-tube partial premixing due to the reverse flow near the nozzle exit as well as enhanced mixing due to coherent vortical structures and increased turbulence.

Thermal Transport in Graphene Oxide – From Ballistic Extreme to Amorphous Limit

PubMed Central

Mu, Xin; Wu, Xufei; Zhang, Teng; Go, David B.; Luo, Tengfei

2014-01-01

Graphene oxide is being used in energy, optical, electronic and sensor devices due to its unique properties. However, unlike its counterpart – graphene – the thermal transport properties of graphene oxide remain unknown. In this work, we use large-scale molecular dynamics simulations with reactive potentials to systematically study the role of oxygen adatoms on the thermal transport in graphene oxide. For pristine graphene, highly ballistic thermal transport is observed. As the oxygen coverage increases, the thermal conductivity is significantly reduced. An oxygen coverage of 5% can reduce the graphene thermal conductivity by ~90% and a coverage of 20% lower it to ~8.8 W/mK. This value is even lower than the calculated amorphous limit (~11.6 W/mK for graphene), which is usually regarded as the minimal possible thermal conductivity of a solid. Analyses show that the large reduction in thermal conductivity is due to the significantly enhanced phonon scattering induced by the oxygen defects which introduce dramatic structural deformations. These results provide important insight to the thermal transport physics in graphene oxide and offer valuable information for the design of graphene oxide-based materials and devices. PMID:24468660

Sensitive, label-free protein assay using 1-ethyl-3-methylimidazolium tetrafluoroborate-supported microchip electrophoresis with laser-induced fluorescence detection.

PubMed

Xu, Yuanhong; Li, Jing; Wang, Erkang

2008-05-01

Based on the dimer-monomer equilibrium movement of the fluorescent dye Pyronin Y (PY), a rapid, simple, highly sensitive, label-free method for protein detection was developed by microchip electrophoresis with LIF detection. PY formed a nonfluorescent dimer induced by the premicellar aggregation of an anionic surfactant, SDS, however, the fluorescence intensity of the system increased dramatically when proteins such as BSA, bovine hemoglobin, cytochrome c, and trypsin were added to the solution due to the transition of dimer to fluorescent monomer. Furthermore, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) instead of PBS was applied as running buffers in microchip electrophoresis. Due to the excellent properties of EMImBF4, not only nonspecific protein adsorption was more efficiently suppressed, but also approximately ten-fold higher fluorescence intensity enhancement was obtained than that using PBS. Under the optimal conditions, detection limits for BSA, bovine hemoglobin, cytochrome c, and trypsin were 1.00x10(-6), 2x10(-6), 7x10(-7), and 5x10(-7) mg/mL, respectively. Thus, without covalent modification of the protein, a protein assay method with high sensitivity was achieved on microchips.

Dramatic secretion of recombinant protein expressed in tobacco cells with a designer glycopeptide tag is highly impacted by medium composition.

PubMed

Zhang, Ningning; Dolan, Maureen; Wu, Di; Phillips, Gregory C; Xu, Jianfeng

2016-12-01

Cell growth medium composition has profound impacts on the O -glycosylation of a "designer" arabinogalactan protein-based module; full glycosylation is essential in directing efficient extracellular secretion of the tagged recombinant protein. Expression of recombinant proteins in plant cells as fusion with a de novo designed hydroxyproline (Hyp)-O-glycosylated peptide (HypGP) tag, termed HypGP engineering technology, resulted in dramatically increased secreted protein yields. This is due to the function of the HypGP tag as a molecular carrier in promoting efficient transport of conjoined proteins into culture media. To optimize the cell culture to achieve the best secreted protein yields, the medium effects on the cell growth and protein secretion were investigated using as a model system the tobacco BY-2 cell expressing enhanced green fluorescence protein (EGFP) fused with a (SP) 32 tag (32 tandem repeats of "Ser-Pro" motif). The (SP) 32 tag was found to undergo two-stage Hyp-O-glycosylation in plant cells with the dramatic secretion of the conjoined EGFP correlating with the triggering of the second-stage glycosylation. The BY-2 cell culture in SH medium generated a high secreted protein yield (125 mg/L) with a low cell biomass accumulation (~7.5 gDW/L). In contrast, very low secreted protein yields (~1.5 mg/L) with a high cell biomass accumulation (13.5 gDW/L) were obtained in MS medium. The macronutrients, specifically, the nitrogen supply greatly impacted the glycosylation of the (SP) 32 tag and subsequent protein secretion. Modified MS medium with reduced nitrogen levels boosted the secreted EGFP yields to 168 mg/L. This study demonstrates the profound impacts of medium composition on the secreted yields of a HypGP-tagged protein, and provides a basis for medium design to achieve the highest productivity of the HypGP engineering technology.

Regional climate response collaboratives: Multi-institutional support for climate resilience

USDA-ARS?s Scientific Manuscript database

Federal investments by U.S. agencies to enhance climate resilience at regional scales have grown dramatically over the last five years. This leads to questions about how best to leverage existing agency-specific research, infrastructure, and capacity while avoiding redundancy. This article discusses...

The effect of organic amendments on microbial nitrogen cycling in orchard soils

USDA-ARS?s Scientific Manuscript database

Soil microorganisms have the potential to dramatically alter the nitrogen (N) availability in agricultural systems. It is unclear whether manipulation of microbes to enhance soil N availability and increase agricultural efficiency is possible. Ideally, a management strategy would maximize the amount...

Liquid-state carbon-13 hyperpolarization generated in an MRI system for fast imaging

PubMed Central

Schmidt, A. B.; Berner, S.; Schimpf, W.; Müller, C.; Lickert, T.; Schwaderlapp, N.; Knecht, S.; Skinner, J. G.; Dost, A.; Rovedo, P.; Hennig, J.; von Elverfeldt, D.; Hövener, J. -B.

2017-01-01

Hyperpolarized (HP) tracers dramatically increase the sensitivity of magnetic resonance imaging (MRI) to monitor metabolism non-invasively and in vivo. Their production, however, requires an extra polarizing device (polarizer) whose complexity, operation and cost can exceed that of an MRI system itself. Furthermore, the lifetime of HP tracers is short and some of the enhancement is lost during transfer to the application site. Here, we present the production of HP tracers in water without an external polarizer: by Synthesis Amid the Magnet Bore, A Dramatically Enhanced Nuclear Alignment (SAMBADENA) is achieved within seconds, corresponding to a hyperpolarization of ∼20%. As transfer of the tracer is no longer required, SAMBADENA may permit a higher polarization at the time of detection at a fraction of the cost and complexity of external polarizers. This development is particularly promising in light of the recently extended portfolio of biomedically relevant para-hydrogen-tracers and may lead to new diagnostic applications. PMID:28262691

Investigation on laser-plasma coupling in intense, ultrashort irradiation of a nanostructured silicon target

NASA Astrophysics Data System (ADS)

Cristoforetti, G.; Anzalone, A.; Baffigi, F.; Bussolino, G.; D'Arrigo, G.; Fulgentini, L.; Giulietti, A.; Koester, P.; Labate, L.; Tudisco, S.; Gizzi, L. A.

2014-09-01

One of the most interesting research fields in laser-matter interaction studies is the investigation of effects and mechanisms produced by nano- or micro-structured targets, mainly devoted to the enhancing of laser-target or laser-plasma coupling. In intense and ultra-intense laser interaction regimes, the observed enhancement of x-ray plasma emission and/or hot electron conversion efficiency is explained by a variety of mechanisms depending on the dimensions and shape of the structures irradiated. In the present work, the attention is mainly focused on the lowering of the plasma formation threshold which is induced by the larger absorptivity. Flat and nanostructured silicon targets were here irradiated with an ultrashort laser pulse, in the range 1 × 1017-2 × 1018 W µm2 cm-2. The effects of structures on laser-plasma coupling were investigated at different laser pulse polarizations, by utilizing x-ray yield and 3/2ω harmonics emission. While the measured enhancement of x-ray emission is negligible at intensities larger than 1018 W µm2 cm-2, due to the destruction of the structures by the amplified spontaneous emission (ASE) pre-pulse, a dramatic enhancement, strongly dependent on pulse polarization, was observed at intensities lower than ˜3.5 × 1017 W µm2 cm-2. Relying on the three-halves harmonic emission and on the non-isotropic character of the x-ray yield, induced by the two-plasmon decay instability, the results are explained by the significant lowering of the plasma threshold produced by the nanostructures. In this view, the strong x-ray enhancement obtained by s-polarized pulses is produced by the interaction of the laser pulse with the preplasma, resulting from the interaction of the ASE pedestal with the nanostructures.

A novel vesicular carrier, transethosome, for enhanced skin delivery of voriconazole: characterization and in vitro/in vivo evaluation.

PubMed

Song, Chung Kil; Balakrishnan, Prabagar; Shim, Chang-Koo; Chung, Suk-Jae; Chong, Saeho; Kim, Dae-Duk

2012-04-01

This study describes a novel carrier, transethosome, for enhanced skin delivery of voriconazole. Transethosomes (TELs) are composed of phospholipid, ethanol, water and edge activator (surfactants) or permeation enhancer (oleic acid). Characterization of the TELs was based on results from recovery, particle size, transmission electron microscopy (TEM), zeta potential and elasticity studies. In addition, skin permeation profile was obtained using static vertical diffusion Franz cells and hairless mouse skin treated with TELs containing 0.3% (w/w) voriconazole, and compared with those of ethosomes (ELs), deformable liposomes (DLs), conventional liposomes (CLs) and control (polyethylene glycol, PG) solutions. The recovery of the studied vesicles was above 90% in all vesicles, as all of them contained ethanol (7-30%). There was no significant difference in the particles size of all vesicles. The TEM study revealed that the TELs were in irregular spherical shape, implying higher fluidity due to perturbed lipid bilayer compared to that of other vesicles which were of spherical shape. The zeta potential of vesicles containing sodium taurocholate or oleic acid showed higher negative value compared to other vesicles. The elasticities of ELs and TELs were much higher than that of CLs and DLs. Moreover, TELs dramatically enhanced the skin permeation of voriconazole compared to the control and other vesicles (p<0.05). Moreover, the TELs enhanced both in vitro and in vivo skin deposition of voriconazole in the dermis/epidermis region compared to DLs, CLs and control. Therefore, based on the current study, the novel carrier TELs could serve as an effective dermal delivery for voriconazole. Copyright © 2011 Elsevier B.V. All rights reserved.

Plasmon resonance enhanced multicolour photodetection by graphene

PubMed Central

Liu, Yuan; Cheng, Rui; Liao, Lei; Zhou, Hailong; Bai, Jingwei; Liu, Gang; Liu, Lixin; Huang, Yu; Duan, Xiangfeng

2012-01-01

Graphene has the potential for high-speed, wide-band photodetection, but only with very low external quantum efficiency and no spectral selectivity. Here we report a dramatic enhancement of the overall quantum efficiency and spectral selectivity that enables multicolour photodetection, by coupling graphene with plasmonic nanostructures. We show that metallic plasmonic nanostructures can be integrated with graphene photodetectors to greatly enhance the photocurrent and external quantum efficiency by up to 1,500%. Plasmonic nanostructures of variable resonance frequencies selectively amplify the photoresponse of graphene to light of different wavelengths, enabling highly specific detection of multicolours. Being atomically thin, graphene photodetectors effectively exploit the local plasmonic enhancement effect to achieve a significant enhancement factor not normally possible with traditional planar semiconductor materials. PMID:22146398

Development of Press Hardening Steel with High Resistance to Hydrogen Embrittlement

NASA Astrophysics Data System (ADS)

Bian, Jian; Mohrbacher, Hardy; Lu, Hongzhou; Wang, Wenjun

Press hardening has become the state-of-art technology in the car body manufacturing to enhance safety standard and to reduce CO2 emission of new vehicles. However the delayed cracking due to hydrogen embrittlement remains to be a critical issue. Generally press hardening steel is susceptible to hydrogen embrittlement due to ultra-high strength and martensitic microstructure. The hydrogen charging tests clearly demonstrate that only a few ppm of diffusible hydrogen is sufficient to cause such embrittlement. Currently the hydrogen embrittlement cannot be detected in the press hardened components and the embitteled components could collapse in the crash situation with fatal consequences arisen through dramatic loss in both strength and ductility. This paper introduces a new metallurgical solution to increase the resistance to hydrogen embrittlement of conventional press hardening steel based on 22MnB5 by Nb microalloying. In the hydrogen embrittlement and permeation tests the impact of Nb microalloying on the hydrogen embrittlement behavior was investigated under different hydrogen charging conditions and constant load. The test results revealed that Nb addition increases the resistance to hydrogen embrittlement due to reduced hydrogen diffusivity. The focus of this paper is to investigate the precipitation behavior of microalloying elements by using TEM and STEM and to find out the mechanisms leading to higher performance against hydrogen embrittlement of Nb alloyed steels.

Erythrocyte membrane fluidity and indices of plasmatic oxidative damage after acute physical exercise in humans.

PubMed

Berzosa, C; Gómez-Trullén, E M; Piedrafita, E; Cebrián, I; Martínez-Ballarín, E; Miana-Mena, F J; Fuentes-Broto, L; García, J J

2011-06-01

Optimal levels of membrane fluidity are essential for numerous cell functions including cell growth, solute transport and signal transduction. Since exercise enhances free radical production, our aim was to evaluate in healthy male subjects the effects of an acute bout of maximal and submaximal exercise on the erythrocyte membrane fluidity and its possible relation to the oxidative damage overproduction due to exercise. Subjects (n = 34) performed three cycloergometric tests: a continuous progressive exercise, a strenuous exercise until exhaustion and an acute bout of exercise at an intensity corresponding to 70% of maximal work capacity for 30 min. Venous blood samples were collected before and immediately after these exercises. Erythrocyte membrane fluidity was assessed by fluorescence spectroscopy. Plasma malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA) concentrations and carbonyl content of plasmatic proteins were used as an index of lipid and protein oxidation, respectively. Exercise produced a dramatic drop in the erythrocyte membrane fluidity as compared to resting time, but this was not accompanied by significant changes in the plasmatic MDA and 4-HDA concentrations. The highest erythrocyte membrane rigidity was detected immediately after strenuous exercise until exhaustion was performed. Protein carbonyl levels were higher after exhaustive exercises than at rest. Continuous progressive and strenuous exercises until exhaustion, but not submaximal workload, resulted in a significant enhanced accumulation of carbonylated proteins in the plasma. These findings are consistent with the idea that exercise exaggerates oxidative damage, which may contribute, at least partially, to explain the rigidity in the membrane of the erythrocytes due to acute exercise.

ROTATIONAL SYNCHRONIZATION MAY ENHANCE HABITABILITY FOR CIRCUMBINARY PLANETS: KEPLER BINARY CASE STUDIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mason, Paul A.; Zuluaga, Jorge I.; Cuartas-Restrepo, Pablo A.

2013-09-10

We report a mechanism capable of reducing (or increasing) stellar activity in binary stars, thereby potentially enhancing (or destroying) circumbinary habitability. In single stars, stellar aggression toward planetary atmospheres causes mass-loss, which is especially detrimental for late-type stars, because habitable zones are very close and activity is long lasting. In binaries, tidal rotational breaking reduces magnetic activity, thus reducing harmful levels of X-ray and ultraviolet (XUV) radiation and stellar mass-loss that are able to erode planetary atmospheres. We study this mechanism for all confirmed circumbinary (p-type) planets. We find that main sequence twins provide minimal flux variation and in somemore » cases improved environments if the stars rotationally synchronize within the first Gyr. Solar-like twins, like Kepler 34 and Kepler 35, provide low habitable zone XUV fluxes and stellar wind pressures. These wide, moist, habitable zones may potentially support multiple habitable planets. Solar-type stars with lower mass companions, like Kepler 47, allow for protected planets over a wide range of secondary masses and binary periods. Kepler 38 and related binaries are marginal cases. Kepler 64 and analogs have dramatically reduced stellar aggression due to synchronization of the primary, but are limited by the short lifetime. Kepler 16 appears to be inhospitable to planets due to extreme XUV flux. These results have important implications for estimates of the number of stellar systems containing habitable planets in the Galaxy and allow for the selection of binaries suitable for follow-up searches for habitable planets.« less

ENHANCED FORMATION OF DIOXINS AND FURANS FROM COMBUSTION DEVICES BY ADDITION OF TRACE QUANTITIES OF BROMINE

EPA Science Inventory

Past pilot-scale experimental studies have shown a dramatic increase in the formation of certain chlorinated products of incomplete combustion (PICs) caused by the addition of trace amounts of bromine (Br). Emissions of trichloroethylene and tetrachloorethylene, generated as PICs...

Use of Technology Solutions to Improve CAD Instruction

ERIC Educational Resources Information Center

Ault, Holly K.; Fraser, Alister

2012-01-01

Engineering Graphics curricula have changed dramatically in the past three decades. In the past, students in nearly all engineering disciplines were instructed in manual drafting and descriptive geometry. Students spent many hours "on the board", and this training enhanced the students' graphics communication, design and visualization…

NRMRL'S NUTRIENT-RELATED RISK MANAGEMENT RESEARCH

EPA Science Inventory

Anthropogenic loadings of nutrients into our Nation's atmosphere, aquatic, and terrestrial ecosystems have increased dramatically within the past few decades. Environmental impairments associated with this over fertilization include aquatic habitat loss due to low dissolved oxyge...

Targeted, On-Demand Charge Conversional Nanotherapeutics for Advanced Prostate Cancer

DTIC Science & Technology

2014-09-01

remarkably enhanced cellular uptake of the nanomicelles upon reaching lesion sites, thus improving the drug efficacy as verified by the in vitro...cancer cells (MCF-7) were cultured in RPMI1640 containing 10% heat-inac- tivated fetal calf serum (FCS), 4 mM L-glutamine (Gibco), peni - cillin (100 U mL...restrain the complete binding of Pep-b-PEG-b- PTMC micelles to HA, they still displayed dramatically enhanced HA affinities over Pep-free MPEG-b-PTMC

[Resistance training is an underutilized therapy in obesity and advanced age].

PubMed

Sundell, Jan

2011-01-01

The prevalence and costs of obesity, type 2 diabetes and frailty syndrome will increase dramatically. Resistance training not only decreases fat mass and central obesity, but also enhances insulin sensitivity. Resistance training is probably the most effective measure to prevent and treat sarcopenia. Many studies have shown that resistance training can maintain or even increase bone mineral density. Optimal nutrition enhances the anabolic effect of resistance training. Resistance training should be a central component of public health promotion programs along with aerobic exercise.

Engineering Enhanced Vaccine Cell Lines To Eradicate Vaccine-Preventable Diseases: the Polio End Game

PubMed Central

van der Sanden, Sabine M. G.; Wu, Weilin; Dybdahl-Sissoko, Naomi; Weldon, William C.; Brooks, Paula; O'Donnell, Jason; Jones, Les P.; Brown, Cedric; Tompkins, S. Mark; Karpilow, Jon; Tripp, Ralph A.

2015-01-01

ABSTRACT Vaccine manufacturing costs prevent a significant portion of the world's population from accessing protection from vaccine-preventable diseases. To enhance vaccine production at reduced costs, a genome-wide RNA interference (RNAi) screen was performed to identify gene knockdown events that enhanced poliovirus replication. Primary screen hits were validated in a Vero vaccine manufacturing cell line using attenuated and wild-type poliovirus strains. Multiple single and dual gene silencing events increased poliovirus titers >20-fold and >50-fold, respectively. Host gene knockdown events did not affect virus antigenicity, and clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9-mediated knockout of the top candidates dramatically improved viral vaccine strain production. Interestingly, silencing of several genes that enhanced poliovirus replication also enhanced replication of enterovirus 71, a clinically relevant virus to which vaccines are being targeted. The discovery that host gene modulation can markedly increase virus vaccine production dramatically alters mammalian cell-based vaccine manufacturing possibilities and should facilitate polio eradication using the inactivated poliovirus vaccine. IMPORTANCE Using a genome-wide RNAi screen, a collection of host virus resistance genes was identified that, upon silencing, increased poliovirus and enterovirus 71 production by from 10-fold to >50-fold in a Vero vaccine manufacturing cell line. This report provides novel insights into enterovirus-host interactions and describes an approach to developing the next generation of vaccine manufacturing through engineered vaccine cell lines. The results show that specific gene silencing and knockout events can enhance viral titers of both attenuated (Sabin strain) and wild-type polioviruses, a finding that should greatly facilitate global implementation of inactivated polio vaccine as well as further reduce costs for live-attenuated oral polio vaccines. This work describes a platform-enabling technology applicable to most vaccine-preventable diseases. PMID:26581994

Social Media Use to Enhance Internal Communication: Course Design for Business Students

ERIC Educational Resources Information Center

Young, Amy M.; Hinesly, Mary D.

2014-01-01

Organizations are increasingly using social media to improve their internal communication. When successfully implemented, such initiatives can have a dramatic impact on internal efficiency, team collaboration, innovation, organizational alignment, and cultural transformation. This article describes a course offered by the Ross School of Business,…

Vegetable Soup: Parent-Teacher Guide.

ERIC Educational Resources Information Center

New York State Education Dept. , Albany. Bureau of Mass Communications.

The goal of Vegetable Soup, a television series for children, is to help counter the negative, destructive effects of racial prejudice and racial isolation and to reinforce and dramatize the positive, life enhancing value of human diversity in entertaining and affective presentations that children can understand and relate to. This teaching guide…

Improving the Value Chain of Biofuel Manufacturing Operations by Enhancing Coproduct Transportation and Logistics

USDA-ARS?s Scientific Manuscript database

Biofuels, including corn-based ethanol, can partially meet the increasing demand for transportation fuels. The production of ethanol in the U.S. has dramatically increased; so too has the quantity of manufacturing coproducts. These nonfermentable residues (i.e., proteins, fibers, oils) are sold as...

Quantitative Investigation of the Technologies That Support Cloud Computing

ERIC Educational Resources Information Center

Hu, Wenjin

2014-01-01

Cloud computing is dramatically shaping modern IT infrastructure. It virtualizes computing resources, provides elastic scalability, serves as a pay-as-you-use utility, simplifies the IT administrators' daily tasks, enhances the mobility and collaboration of data, and increases user productivity. We focus on providing generalized black-box…

Targeting consumer needs through marketing research.

PubMed

Inguanzo, J M

1986-11-01

The importance of marketing research in health care has increased dramatically in recent years as hospitals grapple to maintain a place in today's uncertain market. This article examines how marketing research can enhance the effectiveness of your hospital's internal and external communications by identifying programs and services considered most important by consumers.

Spotlight on Young Children and the Creative Arts

ERIC Educational Resources Information Center

Koralek, Derry

2005-01-01

The creative arts--including music, movement, dramatic play, puppetry, painting, sculpture, and drawing--are a crucial part of early childhood. Not only do the arts allow children to express themselves, but creative activity can enhance development of children's skills in literacy, science, math, social studies, and more. This engaging collection…

The Doubling Moment: Resurrecting Edgar Allan Poe

ERIC Educational Resources Information Center

Minnick, J. Bradley; Mergil, Fernando

2008-01-01

This article expands upon Jeffrey Wilhelm's and Brian Edmiston's (1998) concept of a doubling of viewpoints by encouraging middle level students to use dramatization to take on multiple perspectives, to pose interpretive questions, and to enhance critical inquiry from inside and outside of texts. The doubling moment is both the activation of…

How Can Neuroscience Enhance Gifted Education?

ERIC Educational Resources Information Center

Newman, Sharlene D.

2009-01-01

With the advent of imaging techniques like functional magnetic resonance imaging (fMRI) over the past couple of decades, the people's understanding of the brain has increased dramatically. One of the newer research frontiers is the discovery of neural underpinnings of individual differences in cognitive ability. This research has the potential to…

Enhanced Online Access Requires Redesigned Delivery Options and Cost Models

ERIC Educational Resources Information Center

Stern, David

2007-01-01

Rapidly developing online information technologies provide dramatically new capabilities and opportunities, and place new responsibilities on all involved to recreate networks for scholarly communication. Collaborations between all segments of the information network are made possible and necessary as we attempt to find a balanced and mutually…

"The City": The Rhetoric of Rhythm.

ERIC Educational Resources Information Center

Medhurst, Martin J.; Benson, Thomas W.

1981-01-01

Case study of Ralph Steiner and Willard Van Dyke's classic documentary, "The City," a work of cinematic art and a record of the problems confronting urban planners. Discusses how the film builds a rhythmic pattern through dramatic structure, image content and composition, editing, music, and narration to enhance its rhetorical appeal. (JMF)

China in the Year 2000: Modernization Global Power and the Strategic Balance,

DTIC Science & Technology

1981-03-16

productivity, the prospects for China’s modernization are dramatically enhanced. A comparatively high level of social cohesion is another factor in...resources, political skill, social cohesion and national will to eventually become a superpower, but it will take more time than the brief span of two

Uniform thin films of CdSe and CdSe(ZnS) core(shell) quantum dots by sol-gel assembly: enabling photoelectrochemical characterization and electronic applications.

PubMed

Korala, Lasantha; Wang, Zhijie; Liu, Yi; Maldonado, Stephen; Brock, Stephanie L

2013-02-26

Optoelectronic properties of quantum dot (QD) films are limited by (1) poor interfacial chemistry and (2) nonradiative recombination due to surface traps. To address these performance issues, sol-gel methods are applied to fabricate thin films of CdSe and core(shell) CdSe(ZnS) QDs. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) imaging with chemical analysis confirms that the surface of the QDs in the sol-gel thin films are chalcogen-rich, consistent with an oxidative-induced gelation mechanism in which connectivity is achieved by formation of dichalcogenide covalent linkages between particles. The ligand removal and assembly process is probed by thermogravimetric, spectroscopic, and microscopic studies. Further enhancement of interparticle coupling via mild thermal annealing, which removes residual ligands and reinforces QD connectivity, results in QD sol-gel thin films with superior charge transport properties, as shown by a dramatic enhancement of electrochemical photocurrent under white light illumination relative to thin films composed of ligand-capped QDs. A more than 2-fold enhancement in photocurrent, and a further increase in photovoltage can be achieved by passivation of surface defects via overcoating with a thin ZnS shell. The ability to tune interfacial and surface characteristics for the optimization of photophysical properties suggests that the sol-gel approach may enable formation of QD thin films suitable for a range of optoelectronic applications.

Mixed convection heat transfer enhancement in a cubic lid-driven cavity containing a rotating cylinder through the introduction of artificial roughness on the heated wall

NASA Astrophysics Data System (ADS)

Kareem, Ali Khaleel; Gao, Shian

2018-02-01

The aim of the present numerical investigation is to comprehensively analyse and understand the heat transfer enhancement process using a roughened, heated bottom wall with two artificial rib types (R-s and R-c) due to unsteady mixed convection heat transfer in a 3D moving top wall enclosure that has a central rotating cylinder, and to compare these cases with the smooth bottom wall case. These different cases (roughened and smooth bottom walls) are considered at various clockwise and anticlockwise rotational speeds, -5 ≤ Ω ≤ 5, and Reynolds numbers of 5000 and 10 000. The top and bottom walls of the lid-driven cavity are differentially heated, whilst the remaining cavity walls are assumed to be stationary and adiabatic. A standard k-ɛ model for the Unsteady Reynolds-Averaged Navier-Stokes equations is used to deal with the turbulent flow. The heat transfer improvement is carefully considered and analysed through the detailed examinations of the flow and thermal fields, the turbulent kinetic energy, the mean velocity profiles, the wall shear stresses, and the local and average Nusselt numbers. It has been concluded that artificial roughness can strongly affect the thermal fields and fluid flow patterns. Ultimately, the heat transfer rate has been dramatically increased by involving the introduced artificial rips. Increasing the cylinder rotational speed or Reynolds number can enhance the heat transfer process, especially when the wall roughness exists.

Activated carbon enhanced anaerobic digestion of food waste - Laboratory-scale and Pilot-scale operation.

PubMed

Zhang, Le; Zhang, Jingxin; Loh, Kai-Chee

2018-05-01

Effects of activated carbon (AC) supplementation on anaerobic digestion (AD) of food waste were elucidated in lab- and pilot-scales. Lab-scale AD was performed in 1 L and 8 L digesters, while pilot-scale AD was conducted in a 1000 L digester. Based on the optimal dose of 15 g AC per working volume derived from the 1 L digester, for the same AC dosage in the 8 L digester, an improved operation stability coupled with a higher methane yield was achieved even when digesters without AC supplementation failed after 59 days due to accumulation of substantial organic intermediates. At the same time, color removal from the liquid phase of the digestate was dramatically enhanced and the particle size of the digestate solids was increased by 53% through AC supplementation after running for 59 days. Pyrosequencing of 16S rRNA gene showed the abundance of predominant phyla Firmicutes, Elusimicrobia and Proteobacteria selectively enhanced by 1.7-fold, 2.9-fold and 2.1-fold, respectively. Pilot-scale digester without AC gave an average methane yield of 0.466 L⋅(gVS) -1 ⋅d -1 at a composition of 53-61% v/v methane. With AC augmentation, an increase of 41% in methane yield was achieved in the 1000 L digester under optimal organic loading rate (1.6 g VS FW ·L -1 ·d -1 ). Copyright © 2018 Elsevier Ltd. All rights reserved.

Ultrasensitive Raman sensor based on a highly scattering porous structure

NASA Astrophysics Data System (ADS)

Yakovlev, V. V.

2010-02-01

Analytical methods capable of in situ monitoring of water quality have been in high demand for environmental safety, the identification of minute impurities and fundamental understanding of potential risks of these molecular species. Raman spectroscopy, which provides 'fingerprint' information about molecular species in the excitation volume, is a powerful tool for in vivo diagnostics. However, due to a relatively weak Raman signal (~ 1 out of 1014 incident photons produces the useful signal) there is a need to significantly (by many orders of magnitude) enhance this signal, to raise the detection sensitivity of this technique. Traditionally, surface enhanced Raman spectroscopy is employed to dramatically increase the local field intensity and substantially improve the efficiency of Raman scattering. However, the above enhancement occurs only in "hot spots", which represent only a small percent of the total surface are of the substrate. Plasmonic nanostructures are also found to be hard to manufacture in large quantities with the desired degree of reproducibility and to be unable to handle high laser power. We propose and experimentally demonstrate a new type of approach for ultrasensitive Raman sensing. It is based on manufacturing a random porous structure of high-index material, such as GaP, and use the effect of light localization to help improving the detection sensitivity of such sensor. The desired structure was manufactured using electrochemical etching of GaP wafers. The observed Raman signal amplitudes are favorably compared to the best known plasmonic substrates.

Uniform Thin Films of CdSe and CdSe(ZnS) Core(shell) Quantum Dots by Sol-Gel Assembly: Enabling Photoelectrochemical Characterization and Electronic Applications

PubMed Central

Korala, Lasantha; Wang, Zhijie; Liu, Yi; Maldonado, Stephen; Brock, Stephanie L.

2013-01-01

Optoelectronic properties of quantum dot (QD) films are limited by (1) poor interfacial chemistry and (2) non-radiative recombination due to surface traps. To address these performance issues, sol-gel methods are applied to fabricate thin films of CdSe and core(shell) CdSe(ZnS) QDs. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) imaging with chemical analysis confirms that the surface of the QDs in the sol-gel thin films are chalcogen-rich, consistent with an oxidative-induced gelation mechanism in which connectivity is achieved by formation of dichalcogenide covalent linkages between particles. The ligand removal and assembly process is probed by thermogravimetric, spectroscopic and microscopic studies. Further enhancement of inter-particle coupling via mild thermal annealing, which removes residual ligands and reinforces QD connectivity, results in QD sol-gel thin films with superior charge transport properties, as shown by a dramatic enhancement of electrochemical photocurrent under white light illumination relative to thin films composed of ligand-capped QDs. A more than 2-fold enhancement in photocurrent, and a further increase in photovoltage can be achieved by passivation of surface defects via overcoating with a thin ZnS shell. The ability to tune interfacial and surface characteristics for the optimization of photophysical properties suggests that the sol-gel approach may enable formation of QD thin films suitable for a range of optoelectronic applications. PMID:23350924

Synthesis of mannosylinositol phosphorylceramides is involved in maintenance of cell integrity of yeast Saccharomyces cerevisiae.

PubMed

Morimoto, Yuji; Tani, Motohiro

2015-02-01

Complex sphingolipids play important roles in many physiologically important events in yeast Saccharomyces cerevisiae. In this study, we screened yeast mutant strains showing a synthetic lethal interaction with loss of mannosylinositol phosphorylceramide (MIPC) synthesis and found that a specific group of glycosyltransferases involved in the synthesis of mannan-type N-glycans is essential for the growth of cells lacking MIPC synthases (Sur1 and Csh1). The genetic interaction was also confirmed by repression of MNN2, which encodes alpha-1,2-mannosyltransferase that synthesizes mannan-type N-glycans, by a tetracycline-regulatable system. MNN2-repressed sur1Δ csh1Δ cells exhibited high sensitivity to zymolyase treatment, and caffeine and sodium dodecyl sulfate (SDS) strongly inhibited the growth of sur1Δ csh1Δ cells, suggesting impairment of cell integrity due to the loss of MIPC synthesis. The phosphorylated form of Slt2, a mitogen-activated protein (MAP) kinase activated by impaired cell integrity, increased in sur1Δ csh1Δ cells, and this increase was dramatically enhanced by the repression of Mnn2. Moreover, the growth defect of MNN2-repressed sur1Δ csh1Δ cells was enhanced by the deletion of SLT2 or RLM1 encoding a downstream target of Slt2. These results indicated that loss of MIPC synthesis causes impairment of cell integrity, and this effect is enhanced by impaired synthesis of mannan-type N-glycans. © 2014 John Wiley & Sons Ltd.

Simultaneous adsorption of Cd²⁺ and BPA on amphoteric surfactant activated montmorillonite.

PubMed

Liu, Chongmin; Wu, Pingxiao; Zhu, Yajie; Tran, Lytuong

2016-02-01

The study mainly investigated the simultaneous adsorption of bisphenol A (BPA) and Cd(2+) from aqueous solution on octadecane-betaine modified montmorillonite (BS-Mt). The characteristics of the obtained materials were analyzed by X-ray diffraction (XRD), Fourier-transform infrared (FTIR), Specific surface area (BET) and Scanning electron microscopy/Energy disperse spectroscopy (SEM/EDS), confirming that BS-18 was successfully introduced into Mt. Also, factors including initial solution pH, initial Cd(2+)/BPA concentration, contact time and adsorbent dosage on the adsorption processes were shown to be crucial for Cd(2+) adsorption, whereas had negligible effects on BPA adsorption. In this study, we found that pseudo-second-order model fitted well with the adsorption kinetic studies for both Cd(2+) and BPA with an equilibrium time of 24 h. The Cd(2+) and BPA adsorption isotherm could be well described by Freundlich model and Langmuir model, respectively. On the basis of kinetic models, the maximum adsorption capacity of Cd(2+) in aqueous solution was slightly enhanced after modification, indicating that Cd(2+) adsorption on BS-Mt was mainly attributed to direct electrostatic attraction and the chelate reaction, while the dramatic enhancement of maximum adsorption capacity for BPA was due to the hydrophobic interaction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nanoparticle-Formulated Curcumin Prevents Posttherapeutic Disease Reactivation and Reinfection with Mycobacterium tuberculosis following Isoniazid Therapy

PubMed Central

Tousif, Sultan; Singh, Dhiraj Kumar; Mukherjee, Sitabja; Ahmad, Shaheer; Arya, Rakesh; Nanda, Ranjan; Ranganathan, Anand; Bhattacharyya, Maitree; Van Kaer, Luc; Kar, Santosh K.; Das, Gobardhan

2017-01-01

Curcumin, the bioactive component of turmeric also known as “Indian Yellow Gold,” exhibits therapeutic efficacy against several chronic inflammatory and infectious diseases. Even though considered as a wonder drug pertaining to a myriad of reported benefits, the translational potential of curcumin is limited by its low systemic bioavailability due to its poor intestinal absorption, rapid metabolism, and rapid systemic elimination. Therefore, the translational potential of this compound is specifically challenged by bioavailability issues, and several laboratories are making efforts to improve its bioavailability. We developed a simple one-step process to generate curcumin nanoparticles of ~200 nm in size, which yielded a fivefold enhanced bioavailability in mice over regular curcumin. Curcumin nanoparticles drastically reduced hepatotoxicity induced by antitubercular antibiotics during treatment in mice. Most interestingly, co-treatment of nanoparticle-formulated curcumin along with antitubercular antibiotics dramatically reduced the risk for disease reactivation and reinfection, which is the major shortfall of current antibiotic treatment adopted by Directly Observed Treatment Short-course. Furthermore, nanoparticle-formulated curcumin significantly reduced the time needed for antibiotic therapy to obtain sterile immunity, thereby reducing the possibility of generating drug-resistant variants of the organisms. Therefore, adjunct therapy of nano-formulated curcumin with enhanced bioavailability may be beneficial to treatment of tuberculosis and possibly other diseases. PMID:28713372

Enhanced UV light detection using a p-terphenyl wavelength shifter

NASA Astrophysics Data System (ADS)

Joosten, S.; Kaczanowicz, E.; Ungaro, M.; Rehfuss, M.; Johnston, K.; Meziani, Z.-E.

2017-10-01

UV-glass photomultiplier tubes (PMTs) have poor photon detection efficiency for wavelengths below 300 nm due to the opaqueness of the window material. Costly quartz PMTs could be used to enhance the efficiency below 300 nm. A less expensive solution that dramatically improves this efficiency is the application of a thin film of a p-terphenyl (PT) wavelength shifter on UV-glass PMTs. This improvement was quantified for Photonis XP4500B PMTs for wavelengths between 200 nm and 400 nm. The gain factor ranges up to 5 . 4 ± 0 . 5 at a wavelength of 215 nm, with a material load of 110 ± 10 μg /cm2 (894 nm). The wavelength shifter was found to be fully transparent for wavelengths greater than 300 nm. The resulting gain in detection efficiency, when used in a typical C̆erenkov counter, was estimated to be of the order of 40%. Consistent coating quality was assured by a rapid gain testing procedure using narrow-band UV LEDs. Based on these results, 200 Photonis XP4500B PMTs were treated with PT for the upgraded low-threshold C̆erenkov counter (LTCC) to be used in the CEBAF Large Acceptance Spectrometer upgraded detector (CLAS12) at the Thomas Jefferson National Accelerator Facility.

HALO: a reconfigurable image enhancement and multisensor fusion system

NASA Astrophysics Data System (ADS)

Wu, F.; Hickman, D. L.; Parker, Steve J.

2014-06-01

Contemporary high definition (HD) cameras and affordable infrared (IR) imagers are set to dramatically improve the effectiveness of security, surveillance and military vision systems. However, the quality of imagery is often compromised by camera shake, or poor scene visibility due to inadequate illumination or bad atmospheric conditions. A versatile vision processing system called HALO™ is presented that can address these issues, by providing flexible image processing functionality on a low size, weight and power (SWaP) platform. Example processing functions include video distortion correction, stabilisation, multi-sensor fusion and image contrast enhancement (ICE). The system is based around an all-programmable system-on-a-chip (SoC), which combines the computational power of a field-programmable gate array (FPGA) with the flexibility of a CPU. The FPGA accelerates computationally intensive real-time processes, whereas the CPU provides management and decision making functions that can automatically reconfigure the platform based on user input and scene content. These capabilities enable a HALO™ equipped reconnaissance or surveillance system to operate in poor visibility, providing potentially critical operational advantages in visually complex and challenging usage scenarios. The choice of an FPGA based SoC is discussed, and the HALO™ architecture and its implementation are described. The capabilities of image distortion correction, stabilisation, fusion and ICE are illustrated using laboratory and trials data.

Enhanced superconductivity in the high pressure phase of SnAs studied from first principles

NASA Astrophysics Data System (ADS)

Sreenivasa Reddy, P. V.; Kanchana, V.; Millichamp, T. E.; Vaitheeswaran, G.; Dugdale, S. B.

2017-01-01

First principles calculations are performed using density functional theory and density functional perturbation theory for SnAs. Total energy calculations show the first order phase transition from an NaCl structure to a CsCl one at around 37 GPa, which is also confirmed from enthalpy calculations and agrees well with experimental work. Calculations of the phonon structure and hence the electron-phonon coupling, λep, and superconducting transition temperature, Tc, across the phase diagram are performed. These calculations give an ambient pressure Tc, in the NaCl structure, of 3.08 K, in good agreement with experiment whilst at the transition pressure, in the CsCl structure, a drastically increased value of Tc = 12.2 K is found. Calculations also show a dramatic increase in the electronic density of states at this pressure. The lowest energy acoustic phonon branch in each structure also demonstrates some softening effects. Electronic structure calculations of the Fermi surface in both phases are presented for the first time as well as further calculations of the generalised susceptibility with the inclusion of matrix elements. These calculations indicate that the softening is not derived from Fermi surface nesting and it is concluded to be due to a wavevector-dependent enhancement of the electron-phonon coupling.

Structure and activity of Bombyx PBAN.

PubMed

Nagasawa, H; Kuniyoshi, H; Arima, R; Kawano, T; Ando, T; Suzuki, A

1994-01-01

Two structurally related molecular species of pheromone biosynthesis activating neuropeptides (PBANs), PBAN-I and -II, were isolated from adult heads of the silkworm, Bombyx mori, and characterized. PBAN-I is a carboxyl-terminally amidated 33-residue peptide. Structure-activity relationship studies revealed that 1) its carboxyl-terminal pentapeptide is the smallest size showing activity, 2) the carboxyl-terminal amide is indispensable for activity, and 3) oxidation of three Met residues in PBAN-I to Met(O) (methionine sulfoxide) caused marked enhancement of activity, and the three Met(O) residues contribute equally to the enhancement of activity. Molecular design of PBAN analogs using a carboxyl-terminal hexapeptide showed that modification of the amino-terminal amino group brought about a dramatic increase in activity. This increase was presumed to be mainly due to the increased stability in hemolymph. PBANs share the common carboxyl-terminal sequence, -Phe-Xaa-Pro-Arg-Leu-NH2, with myotropic peptides isolated from locust and cockroach. Examination of cross-activity of these two groups of peptides revealed that PBAN and its analogs exhibited myotropic activity comparable to myotropic peptides, while myotropic peptides showed extremely high pheromonotropic activity. In B. mori, PBAN activates sex pheromone (bombykol) production presumably by promoting the reduction reaction from acyl to alcohol, which is the last step in the biosynthesis of bombykol.

Enhanced recovery after surgery: Current research insights and future direction

PubMed Central

Abeles, Aliza; Kwasnicki, Richard Mark; Darzi, Ara

2017-01-01

Since the concept of enhanced recovery after surgery (ERAS) was introduced in the late 1990s the idea of implementing specific interventions throughout the peri-operative period to improve patient recovery has been proven to be beneficial. Minimally invasive surgery is an integral component to ERAS and has dramatically improved post-operative outcomes. ERAS can be applicable to all surgical specialties with the core generic principles used together with added specialty specific interventions to allow for a comprehensive protocol, leading to improved clinical outcomes. Diffusion of ERAS into mainstream practice has been hindered due to minimal evidence to support individual facets and lack of method for monitoring and encouraging compliance. No single outcome measure fully captures recovery after surgery, rather multiple measures are necessary at each stage. More recently the pre-operative period has been the target of a number of strategies to improve clinical outcomes, described as prehabilitation. Innovation of technology in the surgical setting is also providing opportunities to overcome the challenges within ERAS, e.g., the use of wearable activity monitors to record information and provide feedback and motivation to patients peri-operatively. Both modernising ERAS and providing evidence for key strategies across specialties will ultimately lead to better, more reliable patient outcomes. PMID:28289508

NMR longitudinal relaxation enhancement in metal halides by heteronuclear polarization exchange during magic-angle spinning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shmyreva, Anna A.; Safdari, Majid; Furó, István

2016-06-14

Orders of magnitude decrease of {sup 207}Pb and {sup 199}Hg NMR longitudinal relaxation times T{sub 1} upon magic-angle-spinning (MAS) are observed and systematically investigated in solid lead and mercury halides MeX{sub 2} (Me = Pb, Hg and X = Cl, Br, I). In lead(II) halides, the most dramatic decrease of T{sub 1} relative to that in a static sample is in PbI{sub 2}, while it is smaller but still significant in PbBr{sub 2}, and not detectable in PbCl{sub 2}. The effect is magnetic-field dependent but independent of the spinning speed in the range 200–15 000 Hz. The observed relaxation enhancementmore » is explained by laboratory-frame heteronuclear polarization exchange due to crossing between energy levels of spin-1/2 metal nuclei and adjacent quadrupolar-spin halogen nuclei. The enhancement effect is also present in lead-containing organometal halide perovskites. Our results demonstrate that in affected samples, it is the relaxation data recorded under non-spinning conditions that characterize the local properties at the metal sites. A practical advantage of fast relaxation at slow MAS is that spectral shapes with orientational chemical shift anisotropy information well retained can be acquired within a shorter experimental time.« less

Nanoengineering of an Si/MnGe quantum dot superlattice for high Curie-temperature ferromagnetism.

PubMed

Nie, Tianxiao; Kou, Xufeng; Tang, Jianshi; Fan, Yabin; Lee, Shengwei; He, Qinglin; Chang, Li-Te; Murata, Koichi; Gen, Yin; Wang, Kang L

2017-03-02

The realization and application of spintronic devices would be dramatically advanced if room-temperature ferromagnetism could be integrated into semiconductor nanostructures, especially when compatible with mature silicon technology. Herein, we report the observation of such a system - an Si/MnGe superlattice with quantum dots well aligned in the vertical direction successfully grown by molecular beam epitaxy. Such a unique system could take full advantage of the type-II energy band structure of the Si/Ge heterostructure, which could trap the holes inside MnGe QDs, significantly enhancing the hole-mediated ferromagnetism. Magnetic measurements indeed found that the superlattice structure exhibited a Curie temperature of above 400 K. Furthermore, zero-field cooling and field cooling curves could confirm the absence of ferromagnetic compounds, such as Ge 8 Mn 11 (T c ∼ 270 K) and Ge 3 Mn 5 (T c ∼ 296 K) in our system. Magnetotransport measurement revealed a clear magnetoresistance transition from negative to positive and a pronounced anomalous Hall effect. Such a unique Si/MnGe superlattice sets a new stage for strengthening ferromagnetism due to the enhanced hole-mediation by quantum confinement, which can be exploited for realizing the room-temperature Ge-based spin field-effect transistors in the future.

Critical current enhancement driven by suppression of superconducting fluctuation in ion-gated ultrathin FeSe

NASA Astrophysics Data System (ADS)

Harada, T.; Shiogai, J.; Miyakawa, T.; Nojima, T.; Tsukazaki, A.

2018-05-01

The framework of phase transition, such as superconducting transition, occasionally depends on the dimensionality of materials. Superconductivity is often weakened in the experimental conditions of two-dimensional thin films due to the fragile superconducting state against defects and interfacial effects. In contrast to this general trend, superconductivity in the thin limit of FeSe exhibits an opposite trend, such as an increase in critical temperature (T c) and the superconducting gap exceeding the bulk values; however, the dominant mechanism is still under debate. Here, we measured thickness-dependent electrical transport properties of the ion-gated FeSe thin films to evaluate the superconducting critical current (I c) in the ultrathin FeSe. Upon systematically decreasing the FeSe thickness by the electrochemical etching technique in the Hall bar-shaped electric double-layer transistors, we observed a dramatic enhancement of I c reaching about 10 mA and corresponding to about 107 A cm‑2 in the thinnest condition. By analyzing the transition behavior, we clarify that the suppressed superconducting fluctuation is one of the origins of the large I c in the ion-gated ultrathin FeSe films. These results indicate the existence of a robust superconducting state possibly with dense Cooper pairs at the thin limit of FeSe.

Senescent intervertebral disc cells exhibit perturbed matrix homeostasis phenotype.

PubMed

Ngo, Kevin; Patil, Prashanti; McGowan, Sara J; Niedernhofer, Laura J; Robbins, Paul D; Kang, James; Sowa, Gwendolyn; Vo, Nam

2017-09-01

Aging greatly increases the risk for intervertebral disc degeneration (IDD) as a result of proteoglycan loss due to reduced synthesis and enhanced degradation of the disc matrix proteoglycan (PG). How disc matrix PG homeostasis becomes perturbed with age is not known. The goal of this study is to determine whether cellular senescence is a source of this perturbation. We demonstrated that disc cellular senescence is dramatically increased in the DNA repair-deficient Ercc1 -/Δ mouse model of human progeria. In these accelerated aging mice, increased disc cellular senescence is closely associated with the rapid loss of disc PG. We also directly examine PG homeostasis in oxidative damage-induced senescent human cells using an in vitro cell culture model system. Senescence of human disc cells treated with hydrogen peroxide was confirmed by growth arrest, senescence-associated β-galactosidase activity, γH2AX foci, and acquisition of senescence-associated secretory phenotype. Senescent human disc cells also exhibited perturbed matrix PG homeostasis as evidenced by their decreased capacity to synthesize new matrix PG and enhanced degradation of aggrecan, a major matrix PG. of the disc. Our in vivo and in vitro findings altogether suggest that disc cellular senescence is an important driver of PG matrix homeostatic perturbation and PG loss. Published by Elsevier B.V.

Dramatic reduction of void swelling by helium in ion-irradiated high purity α-iron

DOE PAGES

Bhattacharya, Arunodaya; Meslin, Estelle; Henry, Jean; ...

2018-04-11

Effect of helium on void swelling was studied in high-purity α-iron, irradiated using energetic self-ions to 157 displacements per atom (dpa) at 773 K, with and without helium co-implantation up to 17 atomic parts-per-million (appm) He/dpa. Helium is known to enhance cavity formation in metals in irradiation environments, leading to early void swelling onset. In this study, microstructure characterization by transmission electron microscopy revealed compelling evidence of dramatic swelling reduction by helium co-implantation, achieved primarily by cavity size reduction. In conclusion, a comprehensive understanding of helium induced cavity microstructure development is discussed using sink strength ratios of dislocations and cavities.

Transgenic upregulation of the condensed tannin pathway in poplar leads to a dramatic shift in leaf palatability for two tree-feeding Lepidoptera.

PubMed

Boeckler, G Andreas; Towns, Megan; Unsicker, Sybille B; Mellway, Robin D; Yip, Lynn; Hilke, Ines; Gershenzon, Jonathan; Constabel, C Peter

2014-02-01

Transgenic hybrid aspen (Populus tremula x tremuloides) overexpressing the MYB134 tannin regulatory gene show dramatically enhanced condensed tannin (proanthocyanidin) levels, as well as shifts in other phenolic metabolites. A series of insect bioassays with forest tent caterpillars (Malacosoma disstria) and gypsy moth (Lymantria dispar) caterpillars was carried out to determine how this metabolic shift affects food preference and performance of generalist tree-feeding lepidopterans. Both species showed a distinct preference for the high-tannin MYB134 overexpressor plants, and L. dispar performance was enhanced relative to controls. L. dispar reached greater pupal weight and showed reduced time to pupation when reared on the MYB134 overexpressing poplar. These results were unexpected since enhanced condensed tannin levels were predicted to act as feeding deterrents. However, the data may be explained by the observed decrease in the salicinoids (phenolic glycosides) salicortin and tremulacin that accompanied the upregulation of the condensed tannins in the transgenics. We conclude that for these two lepidopteran species, condensed tannin levels are unlikely to be a major determinant of caterpillar food preference or performance. However, our experiments show that overexpression of a single regulatory gene in transgenic aspen can have a significant impact on herbivorous insects.

Dramatic enhancement of enzymatic activity in organic solvents by lyoprotectants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dabulis, K.; Klibanov, A.M.

1993-03-05

When seven different hydrolytic enzymes (four proteases and three lipases) were lyophilized from aqueous solution containing a ligand, N-Ac-L-Phe-NH[sub 2], their catalytic activity in anhydrous solvents was far greater (one to two orders of magnitude) than that of the enzymes lyophilized without the ligand. This ligand-induced activation was expressed regardless of whether the substrate employed in organic solvents structurally resembled the ligand. Furthermore, nonligand lyoprotectants [sorbitol, other sugars, and poly(ethylene glycol)] also dramatically enhanced enzymatic activity in anhydrous solvents when present in enzyme aqueous solution prior to lyophilization. The effects of the ligand and of the lyoprotectants were nonadditive, suggestingmore » the same mechanism of action. Excipient-activated and nonactivated enzymes exhibited identical activities in water. Also, addition of the excipients directly to suspensions of nonactivated enzymes in organic solvents had no appreciable effect on catalytic activity. These observations indicate that the mechanism of the excipient-induced activation is based on the ability of the excipients to alleviate reversible denaturation of enzymes upon lyophilization. Activity enhancement induced by the excipients is displayed even after their removal by washing enzymes with anhydrous solvents. Subtilisin Carlsberg, lyophilized with sorbitol, was found to be a much more efficient practical catalyst than its regular' counterpart.« less

Localizer: fast, accurate, open-source, and modular software package for superresolution microscopy

PubMed Central

Duwé, Sam; Neely, Robert K.; Zhang, Jin

2012-01-01

Abstract. We present Localizer, a freely available and open source software package that implements the computational data processing inherent to several types of superresolution fluorescence imaging, such as localization (PALM/STORM/GSDIM) and fluctuation imaging (SOFI/pcSOFI). Localizer delivers high accuracy and performance and comes with a fully featured and easy-to-use graphical user interface but is also designed to be integrated in higher-level analysis environments. Due to its modular design, Localizer can be readily extended with new algorithms as they become available, while maintaining the same interface and performance. We provide front-ends for running Localizer from Igor Pro, Matlab, or as a stand-alone program. We show that Localizer performs favorably when compared with two existing superresolution packages, and to our knowledge is the only freely available implementation of SOFI/pcSOFI microscopy. By dramatically improving the analysis performance and ensuring the easy addition of current and future enhancements, Localizer strongly improves the usability of superresolution imaging in a variety of biomedical studies. PMID:23208219

Calcium-Responsive Liposomes via a Synthetic Lipid Switch.

PubMed

Lou, Jinchao; Carr, Adam J; Watson, Alexa J; Mattern-Schain, Samuel I; Best, Michael D

2018-03-07

Liposomal drug delivery would benefit from enhanced control over content release. Here, we report a novel avenue for triggering release driven by chemical composition using liposomes sensitized to calcium-a target chosen due to its key roles in biology and disease. To demonstrate this principle, we synthesized calcium-responsive lipid switch 1, designed to undergo conformational changes upon calcium binding. The conformational change perturbs membrane integrity, thereby promoting cargo release. This was shown through fluorescence-based release assays via dose-dependent response depending on the percentage of 1 in liposomes, with minimal background leakage in controls. DLS experiments indicated dramatic changes in particle size upon treatment of liposomes containing 1 with calcium. In a comparison of ten naturally occurring metal cations, calcium provided the greatest release. Finally, STEM images showed significant changes in liposome morphology upon treatment of liposomes containing 1 with calcium. These results showcase lipid switches driven by molecular recognition principles as an exciting avenue for controlling membrane properties. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zitterbewegung and symmetry switching in Klein’s four-group

NASA Astrophysics Data System (ADS)

Chotorlishvili, L.; Zięba, P.; Tralle, I.; Ugulava, A.

2018-01-01

Zitterbewegung is the exotic phenomenon associated either with relativistic electron-positron rapid oscillation or to electron-hole transitions in narrow gap semiconductors. In the present work, we enlarge the concept of Zitterbewegung and show that trembling motion may occur due to dramatic changes in the symmetry of the system. In particular, we exploit a paradigmatic model of quantum chaos, the quantum mathematical pendulum (universal Hamiltonian). The symmetry group of this system is Klein’s four-group that possesses three invariant subgroups. The energy spectrum of the system parametrically depends on the height of the potential barrier, and contains degenerate and non-degenerate areas, corresponding to the different symmetry subgroups. Change in the height of the potential barrier switches the symmetry subgroup and leads to trembling motion. We analyzed mean square fluctuations of the velocity operator and observed that trembling is enhanced in highly excited states. We observed a link between the phenomena of trembling motion and the uncertainty relations of noncommutative operators of the system.

Photoemission from buried interfaces in SrTiO3/LaTiO3 superlattices.

PubMed

Takizawa, M; Wadati, H; Tanaka, K; Hashimoto, M; Yoshida, T; Fujimori, A; Chikamatsu, A; Kumigashira, H; Oshima, M; Shibuya, K; Mihara, T; Ohnishi, T; Lippmaa, M; Kawasaki, M; Koinuma, H; Okamoto, S; Millis, A J

2006-08-04

We have measured photoemission spectra of SrTiO3/LaTiO3 superlattices with a topmost SrTiO3 layer of variable thickness. A finite coherent spectral weight with a clear Fermi cutoff was observed at chemically abrupt SrTiO3/LaTiO3 interfaces, indicating that an "electronic reconstruction" occurs at the interface between the Mott insulator LaTiO3 and the band insulator SrTiO3. For SrTiO3/LaTiO3 interfaces annealed at high temperatures (approximately 1000 degrees C), which leads to Sr/La atomic interdiffusion and hence to the formation of La(1-x)Sr(x)TiO3-like material, the intensity of the incoherent part was found to be dramatically reduced whereas the coherent part with a sharp Fermi cutoff was enhanced due to the spread of charge. These important experimental features are well reproduced by layer dynamical-mean-field-theory calculation.

Special quasiordered structures: Role of short-range order in the semiconductor alloy (GaN) 1 -x(ZnO) x

NASA Astrophysics Data System (ADS)

Liu, Jian; Fernández-Serra, Maria V.; Allen, Philip B.

2016-02-01

This paper studies short-range order (SRO) in the semiconductor alloy (GaN) 1 -x(ZnO) x. Monte Carlo simulations performed on a density functional theory (DFT)-based cluster expansion model show that the heterovalent alloys exhibit strong SRO because of the energetic preference for the valence-matched nearest-neighbor Ga-N and Zn-O pairs. To represent the SRO-related structural correlations, we introduce the concept of special quasiordered structure (SQoS). Subsequent DFT calculations reveal the dramatic influence of SRO on the atomic, electronic, and vibrational properties of the (GaN) 1 -x(ZnO) x alloy. Due to the enhanced statistical presence of the energetically unfavored Zn-N bonds with the strong Zn 3 d -N 2 p repulsion, the disordered alloys exhibit much larger lattice bowing and band-gap reduction than those of the short-range ordered alloys. Lattice vibrational entropy tilts the alloy toward less SRO.

Third order harmonic imaging for biological tissues using three phase-coded pulses.

PubMed

Ma, Qingyu; Gong, Xiufen; Zhang, Dong

2006-12-22

Compared to the fundamental and the second harmonic imaging, the third harmonic imaging shows significant improvements in image quality due to the better resolution, but it is degraded by the lower sound pressure and signal-to-noise ratio (SNR). In this study, a phase-coded pulse technique is proposed to selectively enhance the sound pressure of the third harmonic by 9.5 dB whereas the fundamental and the second harmonic components are efficiently suppressed and SNR is also increased by 4.7 dB. Based on the solution of the KZK nonlinear equation, the axial and lateral beam profiles of harmonics radiated from a planar piston transducer were theoretically simulated and experimentally examined. Finally, the third harmonic images using this technique were performed for several biological tissues and compared with the images obtained by the fundamental and the second harmonic imaging. Results demonstrate that the phase-coded pulse technique yields a dramatically cleaner and sharper contrast image.

Comparative Approaches to Understanding the Relation Between Aging and Physical Function

PubMed Central

Cesari, Matteo; Seals, Douglas R.; Shively, Carol A.; Carter, Christy S.

2016-01-01

Despite dedicated efforts to identify interventions to delay aging, most promising interventions yielding dramatic life-span extension in animal models of aging are often ineffective when translated to clinical trials. This may be due to differences in primary outcomes between species and difficulties in determining the optimal clinical trial paradigms for translation. Measures of physical function, including brief standardized testing batteries, are currently being proposed as biomarkers of aging in humans, are predictive of adverse health events, disability, and mortality, and are commonly used as functional outcomes for clinical trials. Motor outcomes are now being incorporated into preclinical testing, a positive step toward enhancing our ability to translate aging interventions to clinical trials. To further these efforts, we begin a discussion of physical function and disability assessment across species, with special emphasis on mice, rats, monkeys, and man. By understanding how physical function is assessed in humans, we can tailor measurements in animals to better model those outcomes to establish effective, standardized translational functional assessments with aging. PMID:25910845

Superconductivity in Weyl semimetal candidate MoTe2.

PubMed

Qi, Yanpeng; Naumov, Pavel G; Ali, Mazhar N; Rajamathi, Catherine R; Schnelle, Walter; Barkalov, Oleg; Hanfland, Michael; Wu, Shu-Chun; Shekhar, Chandra; Sun, Yan; Süß, Vicky; Schmidt, Marcus; Schwarz, Ulrich; Pippel, Eckhard; Werner, Peter; Hillebrand, Reinald; Förster, Tobias; Kampert, Erik; Parkin, Stuart; Cava, R J; Felser, Claudia; Yan, Binghai; Medvedev, Sergey A

2016-03-14

Transition metal dichalcogenides have attracted research interest over the last few decades due to their interesting structural chemistry, unusual electronic properties, rich intercalation chemistry and wide spectrum of potential applications. Despite the fact that the majority of related research focuses on semiconducting transition-metal dichalcogenides (for example, MoS2), recently discovered unexpected properties of WTe2 are provoking strong interest in semimetallic transition metal dichalcogenides featuring large magnetoresistance, pressure-driven superconductivity and Weyl semimetal states. We investigate the sister compound of WTe2, MoTe2, predicted to be a Weyl semimetal and a quantum spin Hall insulator in bulk and monolayer form, respectively. We find that bulk MoTe2 exhibits superconductivity with a transition temperature of 0.10 K. Application of external pressure dramatically enhances the transition temperature up to maximum value of 8.2 K at 11.7 GPa. The observed dome-shaped superconductivity phase diagram provides insights into the interplay between superconductivity and topological physics.

Superconductivity in Weyl semimetal candidate MoTe2

PubMed Central

Qi, Yanpeng; Naumov, Pavel G.; Ali, Mazhar N.; Rajamathi, Catherine R.; Schnelle, Walter; Barkalov, Oleg; Hanfland, Michael; Wu, Shu-Chun; Shekhar, Chandra; Sun, Yan; Süß, Vicky; Schmidt, Marcus; Schwarz, Ulrich; Pippel, Eckhard; Werner, Peter; Hillebrand, Reinald; Förster, Tobias; Kampert, Erik; Parkin, Stuart; Cava, R. J.; Felser, Claudia; Yan, Binghai; Medvedev, Sergey A.

2016-01-01

Transition metal dichalcogenides have attracted research interest over the last few decades due to their interesting structural chemistry, unusual electronic properties, rich intercalation chemistry and wide spectrum of potential applications. Despite the fact that the majority of related research focuses on semiconducting transition-metal dichalcogenides (for example, MoS2), recently discovered unexpected properties of WTe2 are provoking strong interest in semimetallic transition metal dichalcogenides featuring large magnetoresistance, pressure-driven superconductivity and Weyl semimetal states. We investigate the sister compound of WTe2, MoTe2, predicted to be a Weyl semimetal and a quantum spin Hall insulator in bulk and monolayer form, respectively. We find that bulk MoTe2 exhibits superconductivity with a transition temperature of 0.10 K. Application of external pressure dramatically enhances the transition temperature up to maximum value of 8.2 K at 11.7 GPa. The observed dome-shaped superconductivity phase diagram provides insights into the interplay between superconductivity and topological physics. PMID:26972450

Myomaker: A membrane activator of myoblast fusion and muscle formation

PubMed Central

Millay, Douglas P.; O’Rourke, Jason R.; Sutherland, Lillian B.; Bezprozvannaya, Svetlana; Shelton, John M.; Bassel-Duby, Rhonda; Olson, Eric N.

2013-01-01

Summary Fusion of myoblasts is essential for the formation of multi-nucleated muscle fibers. However, the identity of myogenic proteins that directly govern this fusion process has remained elusive. Here, we discovered a muscle-specific membrane protein, named Myomaker, that controls myoblast fusion. Myomaker is expressed on the cell surface of myoblasts during fusion and is down-regulated thereafter. Over-expression of Myomaker in myoblasts dramatically enhances fusion and genetic disruption of Myomaker in mice causes perinatal death due to an absence of multi-nucleated muscle fibers. Remarkably, forced expression of Myomaker in fibroblasts promotes fusion with myoblasts, demonstrating the direct participation of this protein in the fusion process. Pharmacologic perturbation of the actin cytoskeleton abolishes the activity of Myomaker, consistent with prior studies implicating actin dynamics in myoblast fusion. These findings reveal a long-sought myogenic fusion protein both necessary and sufficient for mammalian myoblast fusion and provide new insights into the molecular underpinnings of muscle formation. PMID:23868259

Nutrient enrichment enhances black band disease progression in corals

NASA Astrophysics Data System (ADS)

Voss, Joshua D.; Richardson, Laurie L.

2006-11-01

Infectious diseases are recognized as significant contributors to the dramatic loss of corals observed worldwide. However, the causes of increased coral disease prevalence and severity are not well understood. One potential factor is elevated nutrient concentration related to localized anthropogenic activities such as inadequate waste water treatment or terrestrial runoff. In this study the effect of nutrient enrichment on the progression of black band disease (BBD) was investigated using both in situ and laboratory experiments. Experimental increases in localized nutrient availability using commercial time release fertilizer in situ resulted in doubling of BBD progression and coral tissue loss in the common reef framework coral Siderastrea siderea. Laboratory experiments in which artificially infected S. siderea colonies were exposed to increased nitrate concentrations (up to 3 μM) demonstrated similar increases in BBD progression. These findings provide evidence that the impacts of this disease on coral populations are exacerbated by nutrient enrichment and that management to curtail excess nutrient loading may be important for reducing coral cover loss due to BBD.

Millimeter-wave MMIC technology for smart weapons

NASA Astrophysics Data System (ADS)

Seashore, Charles R.

1994-12-01

Millimeter wave MMIC component technology has made dramatic progress over the last ten years largely due to funding stimulation received under the ARPA Tri-Service MIMIC program. In several smart weapon systems, MMIC components are now specified as the baseline approach for millimeter wave radar transceiver hardware. Availability of this new frontier in microelectronics has also enabled realization of sensor fusion for multispectral capability to defeat many forms of known countermeasures. The current frequency range for these MMIC-based components is approximately 30 to 100 GHz. In several cases, it has been demonstrated that the MMIC component performance has exceeded that available from hybrid microstrip circuits using selected discrete devices. However, challenges still remain in chip producibility enhancement and cost reduction since many of the essential device structure candidates are themselves emerging technologies with a limited wafer fabrication history and accumulated test databases. It is concluded that smart weapons of the future will rely heavily on advanced microelectronics to satisfy performance requirements as well as meeting stringent packaging and power source constraints.

Poly(imide-siloxane) segmented copolymer structural adhesives prepared by bulk and solution thermal imidization

NASA Technical Reports Server (NTRS)

Bott, R. H.; Summers, J. D.; Arnold, C. A.; Blankenship, C. P., Jr.; Taylor, L. T.

1988-01-01

The improved properties that have been demonstrated through thermal solution imidization in the case of polyimides and poly(imide-siloxane) segmented copolymers suggests significant potential for application of these new materials. Specifically, the enhancement in solubility, moisture reduction, and processability observed through this solution technique is quite dramatic. Previous work has shown that the presence of low amounts of siloxane does not detract significantly from the lap shear strength of these materials to titanium in the case of bulk thermal imidization synthesis. In addition, the siloxane incorporation results in the added advantage of resistance to hot, wet environments. This added durability is presumably due to the hydrophobic siloxane segments preventing the uptake of water at the critical interphase between the adhesive and the adherend. This paper discusses the extension of this work to the solution imidization synthesis technique recently developed in our laboratory. Results dealing with the absolute bond strengths as well as durability and failure surface analysis will be presented.

Investigation of flameholding mechanisms in a kerosene-fueled scramjet combustor

NASA Astrophysics Data System (ADS)

Wang, Yu-hang; Song, Wen-yan; Shi, De-yong

2017-11-01

Laser-induced fluorescence and high-speed photography were employed to investigate the kerosene flame stabilization mechanism in a cavity-based scramjet combustor with an inlet condition corresponds to flight Mach number of 4. Pilot hydrogen was used to ignite the kerosene fuel. The PLIF results of kerosene distribution in the reacting cases showed that the mixing process was dramatically enhanced compared to the non-reacting cases. Sharp OH gradients were observed in the shear layer and the aft region of cavity, which indicated that the flame was located at these positions. A portion of hot products participated in the recirculation of the cavity and preheated the kerosene-air mixture in the leading edge. The heated mixture was ignited in the mid-cavity and the reaction zone spread into the mainstream flow. Due to the competition between the local flame speed and the local flow speed, the high-speed images showed that the spreading location was in fluctuation. This movement was observed to cause a low-frequency wall pressure fluctuation.

Geodesic acoustic mode driven by energetic particles with bump-on-tail distribution

NASA Astrophysics Data System (ADS)

Ren, Haijun; Wang, Hao

2018-04-01

Energetic-particle-driven geodesic acoustic mode (EGAM) is analytically investigated by adopting the bump-on-tail distribution for energetic particles (EPs), which is created by the fact that the charge exchange time (τcx ) is sufficiently shorter than the slowing down time (τsl ). The dispersion relation is derived in the use of gyro-kinetic equations. Due to the finite ratio of the critical energy and the initial energy of EPs, defined as τc , the dispersion relation is numerically evaluated and the effect of finite τc is examined. Following relative simulation and experimental work, we specifically considered two cases: τsl/τcx = 3.4 and τsl/τcx = 20.4 . The pitch angle is shown to significantly enhance the growth rate and meanwhile, the real frequency is dramatically decreased with increasing pitch angle. The excitation of high-frequency EGAM is found, and this is consistent with both the experiment and the simulation. The number density effect of energetic particles, represented by \

Periodically Ordered Nanoporous Perovskite Photoelectrode for Efficient Photoelectrochemical Water Splitting.

PubMed

Shi, Li; Zhou, Wei; Li, Zhao; Koul, Supriya; Kushima, Akihiro; Yang, Yang

2018-06-18

Nonmetallic materials with localized surface plasmon resonance (LSPR) have a great potential for solar energy harvesting applications. Exploring nonmetallic plasmonic materials is desirable yet challenging. Herein, an efficient nonmetallic plasmonic perovskite photoelectrode, namely, SrTiO 3 , with a periodically ordered nanoporous structure showing an intense LSPR in the visible light region is reported. The crystalline-core@amorphous-shell structure of the SrTiO 3 photoelectrode enables a strong LSPR due to the high charge carrier density induced by oxygen vacancies in the amorphous shell. The reversible tunability in LSPR of the SrTiO 3 photoelectrode was observed by oxidation/reduction treatment and incident angle adjusting. Such a nonmetallic plasmonic SrTiO 3 photoelectrode displays a dramatic plasmon-enhanced photoelectrochemical water splitting performance with a photocurrent density of 170.0 μA cm -2 under visible light illumination and a maximum incident photon-to-current-conversion efficiency of 4.0% in the visible light region, which are comparable to the state-of-the-art plasmonic noble metal sensitized photoelectrodes.

An investigation into the effective surface passivation of quantum dots by a photo-assisted chemical method

NASA Astrophysics Data System (ADS)

Joo, So-Yeong; Park, Hyun-Su; Kim, Do-yeon; Kim, Bum-Sung; Lee, Chan Gi; Kim, Woo-Byoung

2018-01-01

In this study, we have developed an effective amino passivation process for quantum dots (QDs) at room temperature and have investigated a passivation mechanism using a photo-assisted chemical method. As a result of the reverse reaction of the H2O molecules, the etching kinetics of the photo-assisted chemical method increased upon increasing the 3-amino-1-propanol (APOL)/H2O ratio of the etching solution. Photon-excited electron-hole pairs lead to strong bonding between the organic and surface atoms of the QDs, and results in an increase of the quantum yield (QY%). This passivation method is also applicable to CdSe/ZnSe core/shell structures of QDs, due to the passivation of mid-gap defects states at the interface. The QY% of the as-synthesized CdSe QDs is dramatically enhanced by the amino passivation from 37% to 75% and the QY% of the CdSe/ZnSe core/shell QDs is also improved by ˜28%.

Glucose 6-phosphate dehydrogenase deficiency enhances germ cell apoptosis and causes defective embryogenesis in Caenorhabditis elegans

PubMed Central

Yang, H-C; Chen, T-L; Wu, Y-H; Cheng, K-P; Lin, Y-H; Cheng, M-L; Ho, H-Y; Lo, S J; Chiu, D T-Y

2013-01-01

Glucose 6-phosphate dehydrogenase (G6PD) deficiency, known as favism, is classically manifested by hemolytic anemia in human. More recently, it has been shown that mild G6PD deficiency moderately affects cardiac function, whereas severe G6PD deficiency leads to embryonic lethality in mice. How G6PD deficiency affects organisms has not been fully elucidated due to the lack of a suitable animal model. In this study, G6PD-deficient Caenorhabditis elegans was established by RNA interference (RNAi) knockdown to delineate the role of G6PD in animal physiology. Upon G6PD RNAi knockdown, G6PD activity was significantly hampered in C. elegans in parallel with increased oxidative stress and DNA oxidative damage. Phenotypically, G6PD-knockdown enhanced germ cell apoptosis (2-fold increase), reduced egg production (65% of mock), and hatching (10% of mock). To determine whether oxidative stress is associated with G6PD knockdown-induced reproduction defects, C. elegans was challenged with a short-term hydrogen peroxide (H2O2). The early phase egg production of both mock and G6PD-knockdown C. elegans were significantly affected by H2O2. However, H2O2-induced germ cell apoptosis was more dramatic in mock than that in G6PD-deficient C. elegans. To investigate the signaling pathways involved in defective oogenesis and embryogenesis caused by G6PD knockdown, mutants of p53 and mitogen-activated protein kinase (MAPK) pathways were examined. Despite the upregulation of CEP-1 (p53), cep-1 mutation did not affect egg production and hatching in G6PD-deficient C. elegans. Neither pmk-1 nor mek-1 mutation significantly affected egg production, whereas sek-1 mutation further decreased egg production in G6PD-deficient C. elegans. Intriguingly, loss of function of sek-1 or mek-1 dramatically rescued defective hatching (8.3- and 9.6-fold increase, respectively) induced by G6PD knockdown. Taken together, these findings show that G6PD knockdown reduces egg production and hatching in C. elegans, which are possibly associated with enhanced oxidative stress and altered MAPK pathways, respectively. PMID:23640458

Functionalized graphene nanomaterials: new insight into direct exfoliation of graphite with supramolecular polymers

NASA Astrophysics Data System (ADS)

Cheng, Chih-Chia; Chang, Feng-Chih; Wang, Jui-Hsu; Chen, Jem-Kun; Yen, Ying-Chieh; Lee, Duu-Jong

2015-12-01

A novel urea-cytosine end-capped polypropylene glycol (UrCy-PPG) can self-assemble into a long-range ordered lamellar microstructure on the surface of graphene, due to the strong specific interactions between UrCy-PPG and graphene. In addition, the graphene composite produced exhibits a high conductivity (~1093 S m-1) with a dramatic thermo-responsive ON/OFF resistance-switching behavior (10 consecutive cycles).A novel urea-cytosine end-capped polypropylene glycol (UrCy-PPG) can self-assemble into a long-range ordered lamellar microstructure on the surface of graphene, due to the strong specific interactions between UrCy-PPG and graphene. In addition, the graphene composite produced exhibits a high conductivity (~1093 S m-1) with a dramatic thermo-responsive ON/OFF resistance-switching behavior (10 consecutive cycles). Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07076g

Dramatically accelerated growth and extraordinary gigantism of transgenic mud loach Misgurnus mizolepis.

PubMed

Nam, Y K; Noh, J K; Cho, Y S; Cho, H J; Cho, K N; Kim, C G; Kim, D S

2001-08-01

Transgenic mud loaches (Misgurnus mizolepis), in which the entire transgene originated from the same species, have been generated by microinjecting the mud loach growth hormone (mlGH) gene fused to the mud loach beta-actin promoter. Out of 4,100 eggs injected, 7.5% fish derived from the injected eggs showed dramatically accelerated growth, with a maximum of 35-fold faster growth than their non-transgenic siblings. Many fast-growing transgenic individuals showed extraordinary gigantism: their body weight and total length (largest fish attained to 413 g and 41.5 cm) were larger and longer than even those of 12-year-old normal broodstock (maximum size reached to 89 g and 28 cm). Of 46 transgenic founders tested, 30 individuals transmitted the transgene to next generation with a wide range of germ-line transmission frequencies ranging from 2% to 33%. The growth performance of the subsequent generation (F1) was also dramatically accelerated up to 35-fold, although the levels of enhanced growth were variable among transgenic lines. Three transgenic germ-lines up to F4 were established, showing the expected Mendelian inheritance of the transgene. Expression of GH mRNA in many tissues was detected by RT-PCR analyses. The time required to attain marketable size (10 g) in these transgenic lines was only 30-50 days after fertilization, while at least 6 months in non-transgenic fish. Besides growth enhancement, significantly improved feed-conversion efficiency up to 1.9-fold was also observed.

Organic light-emitting diodes with a spacer enhanced exciplex emission

NASA Astrophysics Data System (ADS)

Yan, Fei; Chen, Rui; Sun, Handong; Wei Sun, Xiao

2014-04-01

By introducing a spacer molecule into the blended exciplex emissive layer, the performance of the bulk heterojunction exciplex organic light-emitting diodes (OLEDs) was improved dramatically; the maximum luminous efficiency was enhanced by about 22% from 7.9 cd/A to 9.7 cd/A, and the luminous efficiency drop was reduced by 28% at 400 mA/cm2. Besides the suppressed annihilation of exciton, the time-resolved photoluminescence measurements indicated that the spacer enhanced the delayed fluorescence through increasing the backward intersystem crossing rate from the triplet to singlet exciplex state. This method is useful for developing high performance exciplex OLEDs.

Enhanced second-harmonic generation from resonant GaAs gratings.

PubMed

de Ceglia, D; D'Aguanno, G; Mattiucci, N; Vincenti, M A; Scalora, M

2011-03-01

We theoretically study second harmonic generation in nonlinear, GaAs gratings. We find large enhancement of conversion efficiency when the pump field excites the guided mode resonances of the grating. Under these circumstances the spectrum near the pump wavelength displays sharp resonances characterized by dramatic enhancements of local fields and favorable conditions for second-harmonic generation, even in regimes of strong linear absorption at the harmonic wavelength. In particular, in a GaAs grating pumped at 1064 nm, we predict second-harmonic conversion efficiencies approximately 5 orders of magnitude larger than conversion rates achievable in either bulk or etalon structures of the same material.

CO tip functionalization in subatomic resolution atomic force microscopy

NASA Astrophysics Data System (ADS)

Kim, Minjung; Chelikowsky, James R.

2015-10-01

Noncontact atomic force microscopy (nc-AFM) employing a CO-functionalized tip displays dramatically enhanced resolution wherein covalent bonds of polycyclic aromatic hydrocarbon can be imaged. Employing real-space pseudopotential first-principles calculations, we examine the role of CO in functionalizing the nc-AFM tip. Our calculations allow us to simulate full AFM images and ascertain the enhancement mechanism of the CO molecule. We consider two approaches: one with an explicit inclusion of the CO molecule and one without. By comparing our simulations to existing experimental images, we ascribe the enhanced resolution of the CO functionalized tip to the special orbital characteristics of the CO molecule.

CO tip functionalization in subatomic resolution atomic force microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Minjung; Chelikowsky, James R.

2015-10-19

Noncontact atomic force microscopy (nc-AFM) employing a CO-functionalized tip displays dramatically enhanced resolution wherein covalent bonds of polycyclic aromatic hydrocarbon can be imaged. Employing real-space pseudopotential first-principles calculations, we examine the role of CO in functionalizing the nc-AFM tip. Our calculations allow us to simulate full AFM images and ascertain the enhancement mechanism of the CO molecule. We consider two approaches: one with an explicit inclusion of the CO molecule and one without. By comparing our simulations to existing experimental images, we ascribe the enhanced resolution of the CO functionalized tip to the special orbital characteristics of the CO molecule.

Effects of morphology on the radiative properties of internally mixed light absorbing carbon aerosols with different aging status.

PubMed

Cheng, Tianhai; Wu, Yu; Chen, Hao

2014-06-30

Light absorbing carbon aerosols play a substantial role in climate change through radiative forcing, which is the dominant absorber of solar radiation. Radiative properties of light absorbing carbon aerosols are strongly dependent on the morphological factors and the mixing mechanism of black carbon with other aerosol components. This study focuses on the morphological effects on the optical properties of internally mixed light absorbing carbon aerosols using the numerically exact superposition T-matrix method. Three types aerosols with different aging status such as freshly emitted BC particles, thinly coated light absorbing carbon aerosols, heavily coated light absorbing carbon aerosols are studied. Our study showed that morphological factors change with the aging of internally mixed light absorbing carbon aerosols to result in a dramatic change in their optical properties. The absorption properties of light absorbing carbon aerosols can be enhanced approximately a factor of 2 at 0.67 um, and these enhancements depend on the morphological factors. A larger shell/core diameter ratio of volume-equivalent shell-core spheres (S/C), which indicates the degree of coating, leads to stronger absorption. The enhancement of absorption properties accompanies a greater enhancement of scattering properties, which is reflected in an increase in single scattering albedo (SSA). The enhancement of single scattering albedo due to the morphological effects can reach a factor of 3.75 at 0.67 μm. The asymmetry parameter has a similar yet smaller enhancement. Moreover, the corresponding optical properties of shell-and-core model determined by using Lorenz -Mie solutions are presented for comparison. We found that the optical properties of internally mixed light absorbing carbon aerosol can differ fundamentally from those calculated for the Mie theory shell-and-core model, particularly for thinly coated light absorbing carbon aerosols. Our studies indicate that the complex morphology of internally mixed light absorbing carbon aerosols must be explicitly considered in climate radiation balance.

Disrupting Aviation: An Exploratory Study of the Opportunities and Risks of Tablet Computers in Commercial Flight Operations

ERIC Educational Resources Information Center

Boyne, Matthew

2013-01-01

Commercial flight operational safety has dramatically improved in the last 30 years because of enhanced crew coordination, communication, leadership and team development. Technology insertion into cockpit operations, however, has been shown to create crew distractions, resulting in flight safety risks, limited use given policy limitations and…

Next Steps for "Big Data" in Education: Utilizing Data-Intensive Research

ERIC Educational Resources Information Center

Dede, Chris

2016-01-01

Data-informed instructional methods offer tremendous promise for increasing the effectiveness of teaching, learning, and schooling. Yet-to-be-developed data science approaches have the potential to dramatically advance instruction for every student and to enhance learning for people of all ages. Next steps that emerged from a recent National…

Aspects of a Theory of Simplification, Debugging, and Coaching.

ERIC Educational Resources Information Center

Fischer, Gerhard; And Others

This paper analyses new methods of teaching skiing in terms of a computational paradigm for learning called increasingly complex microworlds (ICM). Examining the factors that underlie the dramatic enhancement of the learning of skiing led to the focus on the processes of simplification, debugging, and coaching. These three processes are studied in…

The nurse advocate and care for the caregivers.

PubMed

Loomer, A H; Jacoby, J; Schader, J A

1993-02-01

Dramatic improvement in morale, increased retention and an enhanced atmosphere of optimism resulted from introduction of a Nurse Advocate role in an acute care hospital. Within the context of a collaborative governance model, the Nurse Advocate was able to empower individuals and groups to immediate successes. Use of registry nurses was reduced by 99 percent!

College Environment, Student Involvement, and Intellectual Development: Evidence in China

ERIC Educational Resources Information Center

Chi, Xianglan; Liu, Jinlan; Bai, Yin

2017-01-01

China's higher education system has been marked by dramatic growth since 1999. In response to calls for quality assurance, substantial efforts have been made to improve collegiate environments and enhance student learning. However, only limited empirical research has been conducted to investigate the effects of the college environment on student…

Early Bilingualism Enhances Mechanisms of False-Belief Reasoning

ERIC Educational Resources Information Center

Kovacs, Agnes Melinda

2009-01-01

In their first years, children's understanding of mental states seems to improve dramatically, but the mechanisms underlying these changes are still unclear. Such "theory of mind" (ToM) abilities may arise during development, or have an innate basis, developmental changes reflecting limitations of other abilities involved in ToM tasks (e.g.…

Does Sex (Female versus Male) Influence the Impact of Class Attendance on Examination Performance?

ERIC Educational Resources Information Center

Cortright, Ronald N.; Lujan, Heidi L.; Cox, Julie H.; DiCarlo, Stephen E.

2011-01-01

The "conventional wisdom" is that grades are related to class attendance, i.e., students who attend classes more frequently obtain better grades and class attendance dramatically contributes to enhanced learning. However, the influence of sex (female vs. male) on this relationship is understudied. Furthermore, there have been several studies…

An Interview Reflection on "Intelligent Tutoring Goes to School in the Big City"

ERIC Educational Resources Information Center

Koedinger, Kenneth R.; Aleven, Vincent

2016-01-01

Our 1997 article in "IJAIED" reported on a study that showed that a new algebra curriculum with an embedded intelligent tutoring system (the Algebra Cognitive Tutor) dramatically enhanced high-school students' learning. The main motivation for the study was to demonstrate that intelligent tutors that have cognitive science research…

Disrupted fat distribution and composition due to medium-chain triglycerides in mice with a β-oxidation defect.

PubMed

Tucci, Sara; Flögel, Ulrich; Sturm, Marga; Borsch, Elena; Spiekerkoetter, Ute

2011-08-01

Because of the enhanced recognition of inherited long-chain fatty acid oxidation disorders by worldwide newborn screening programs, an increasing number of asymptomatic patients receive medium-chain triglyceride (MCT) supplements to prevent the development of cardiomyopathy and myopathy. MCT supplementation has been recognized as a safe dietary intervention, but long-term observations into later adulthood are still not available. We investigated the consequences of a prolonged MCT diet on abdominal fat distribution and composition and on liver fat. Mice with very-long-chain acyl-coenzyme A dehydrogenase deficiency (VLCAD(-/-)) were supplemented for 1 y with a diet in which MCTs replaced long-chain triglycerides without increasing the total fat content. The dietary effects on abdominal fat accumulation and composition were analyzed by in vivo (1)H- and (13)C-magnetic resonance spectroscopy (9.4 Tesla). After 1 y of MCT supplementation, VLCAD(-/-) mice accumulated massive visceral fat and had a dramatic increase in the concentration of serum free fatty acids. Furthermore, we observed a profound shift in body triglyceride composition, ie, concentrations of physiologically important polyunsaturated fatty acids dramatically decreased. (1)H-Magnetic resonance spectroscopy analysis and histologic evaluation of the liver also showed pronounced fat accumulation and marked oxidative stress. Although the MCT-supplemented diet has been reported to prevent the development of cardiomyopathy and skeletal myopathy in fatty acid oxidation disorders, our data show that long-term MCT supplementation results in a severe clinical phenotype similar to that of nonalcoholic steatohepatitis and the metabolic syndrome.

Unconventional route to encapsulated ultrasmall gold nanoparticles for high-temperature catalysis.

PubMed

Zhang, Tingting; Zhao, Hongyu; He, Shengnan; Liu, Kai; Liu, Hongyang; Yin, Yadong; Gao, Chuanbo

2014-07-22

Ultrasmall gold nanoparticles (us-AuNPs, <3 nm) have been recently recognized as surprisingly active and extraordinarily effective green catalysts. Their stability against sintering during reactions, however, remains a serious issue for practical applications. Encapsulating such small nanoparticles in a layer of porous silica can dramatically enhance the stability, but it has been extremely difficult to achieve using conventional sol-gel coating methods due to the weak metal/oxide affinity. In this work, we address this challenge by developing an effective protocol for the synthesis of us-AuNP@SiO2 single-core/shell nanospheres. More specifically, we take an alternative route by starting with ultrasmall gold hydroxide nanoparticles, which have excellent affinity to silica, then carrying out controllable silica coating in reverse micelles, and finally converting gold hydroxide particles into well-protected us-AuNPs. With a single-core/shell configuration that prevents sintering of nearby us-AuNPs and amino group modification of the Au/SiO2 interface that provides additional coordinating interactions, the resulting us-AuNP@SiO2 nanospheres are highly stable at high temperatures and show high activity in catalytic CO oxidation reactions. A dramatic and continuous increase in the catalytic activity has been observed when the size of the us-AuNPs decreases from 2.3 to 1.5 nm, which reflects the intrinsic size effect of the Au nanoparticles on an inert support. The synthesis scheme described in this work is believed to be extendable to many other ultrasmall metal@oxide nanostructures for much broader catalytic applications.

Few-layer 1T‧ MoTe2 as gapless semimetal with thickness dependent carrier transport

NASA Astrophysics Data System (ADS)

Song, Peng; Hsu, Chuanghan; Zhao, Meng; Zhao, Xiaoxu; Chang, Tay-Rong; Teng, Jinghua; Lin, Hsin; Loh, Kian Ping

2018-07-01

Semimetal MoTe2 can be a type II Weyl semimetal in the bulk, but monolayer of this material is predicted to be quantum spin hall insulators. This dramatic change in electronic properties with number of layers is an excellent example of the dimensional effects of quantum transport. However, a detailed experimental study of the carrier transport and band structure of ultrathin semimetal MoTe2 is lacking so far. We performed magneto-transport measurements to study the conduction behavior and quantum phase coherence of 1T‧ MoTe2 as a function of its thickness. We show that due to a unique two-band transport mechanism (synergetic contribution from electron conduction and hole conduction), the conduction behavior of 1T‧ MoTe2 changes from metallic to p-type unipolar, and finally to ambipolar as the thickness decreases, suggesting that this effect can be used in devices by effectively controlling the thickness. Our transport studies, optical measurements and first-principles electronic structure calculations reveal that 1T‧ MoTe2 remains gapless down to a few (~2–3) layers. Despite being gapless, 1T‧ MoTe2 exhibits metal-insulator transition at 3-layer thickness, due to enhanced carrier localization effect.

A spatial focusing model for G protein signals. Regulator of G protein signaling (RGS) protien-mediated kinetic scaffolding.

PubMed

Zhong, Huailing; Wade, Susan M; Woolf, Peter J; Linderman, Jennifer J; Traynor, John R; Neubig, Richard R

2003-02-28

Regulators of G protein signaling (RGS) are GTPase-accelerating proteins (GAPs), which can inhibit heterotrimeric G protein pathways. In this study, we provide experimental and theoretical evidence that high concentrations of receptors (as at a synapse) can lead to saturation of GDP-GTP exchange making GTP hydrolysis rate-limiting. This results in local depletion of inactive heterotrimeric G-GDP, which is reversed by RGS GAP activity. Thus, RGS enhances receptor-mediated G protein activation even as it deactivates the G protein. Evidence supporting this model includes a GTP-dependent enhancement of guanosine 5'-3-O-(thio)triphosphate (GTPgammaS) binding to G(i) by RGS. The RGS domain of RGS4 is sufficient for this, not requiring the NH(2)- or COOH-terminal extensions. Furthermore, a kinetic model including only the GAP activity of RGS replicates the GTP-dependent enhancement of GTPgammaS binding observed experimentally. Finally in a Monte Carlo model, this mechanism results in a dramatic "spatial focusing" of active G protein. Near the receptor, G protein activity is maintained even with RGS due to the ability of RGS to reduce depletion of local Galpha-GDP levels permitting rapid recoupling to receptor and maintained G protein activation near the receptor. In contrast, distant signals are suppressed by the RGS, since Galpha-GDP is not depleted there. Thus, a novel RGS-mediated "kinetic scaffolding" mechanism is proposed which narrows the spatial range of active G protein around a cluster of receptors limiting the spill-over of G protein signals to more distant effector molecules, thus enhancing the specificity of G(i) protein signals.

ICT-Isomerization-Induced Turn-On Fluorescence Probe with a Large Emission Shift for Mercury Ion: Application in Combinational Molecular Logic.

PubMed

Bhatta, Sushil Ranjan; Mondal, Bijan; Vijaykumar, Gonela; Thakur, Arunabha

2017-10-02

A unique turn-on fluorescent device based on a ferrocene-aminonaphtholate derivative specific for Hg 2+ cation was developed. Upon binding with Hg 2+ ion, the probe shows a dramatic fluorescence enhancement (the fluorescence quantum yield increases 58-fold) along with a large red shift of 68 nm in the emission spectrum. The fluorescence enhancement with a red shift may be ascribed to the combinational effect of C═N isomerization and an extended intramolecular charge transfer (ICT) mechanism. The response was instantaneous with a detection limit of 2.7 × 10 -9 M. Upon Hg 2+ recognition, the ferrocene/ferrocenium redox peak was anodically shifted by ΔE 1/2 = 72 mV along with a "naked eye" color change from faint yellow to pale orange for this metal cation. Further, upon protonation of the imine nitrogen, the present probe displays a high fluorescence output due to suppression of the C═N isomerization process. Upon deprotonation using strong base, the fluorescence steadily decreases, which indicates that H + and OH - can be used to regulate the off-on-off fluorescence switching of the present probe. Density functional theory studies revealed that the addition of acid leads to protonation of the imine N (according to natural bond orbital analysis), and the resulting iminium proton forms a strong H-bond (2.307 Å) with one of the triazole N atoms to form a five-membered ring, which makes the molecule rigid; hence, enhancement of the ICT process takes place, thereby leading to a fluorescence enhancement with a red shift. The unprecedented combination of H + , OH - , and Hg 2+ ions has been used to generate a molecular system exhibiting the INHIBIT-OR combinational logic operation.

Raman scattering enhanced within the plasmonic gap between an isolated Ag triangular nanoplate and Ag film

NASA Astrophysics Data System (ADS)

Li, Kuanguo; Jiang, Kang; Zhang, Lan; Wang, Yong; Mao, Lei; Zeng, Jie; Lu, Yonghua; Wang, Pei

2016-04-01

Enhanced electromagnetic field in the tiny gaps between metallic nanostructures holds great promise in optical applications. Herein, we report novel out-of-plane nanogaps composed of micrometer-sized Ag triangular nanoplates (AgTN) on Ag films. Notably, the new coupled plasmonic structure can dramatically enhance the surface-enhanced Raman scattering (SERS) by visible laser excitation, although the micrometer-sized AgTN has localized plasmon resonance at infrared wavelength. This enhancement is derived from the gap plasmon polariton between the AgTN and Ag film, which is excited via the antenna effect of the corner and edge of the AgTN. Systematic SERS studies indicated that the plasmon enhancement was on the order of corner > edge > face. These results were further verified by theoretical simulations. Our device paves the way for rational design of sensitive SERS substrates by judiciously choosing appropriate nanoparticles and optimizing the gap distance.

Building a sustainable GIS framework for supporting a tribal transportation problem.

DOT National Transportation Integrated Search

2017-03-01

Due to the recent oil boom, the Fort Berthold Reservation has experienced a dramatic increase in highway and local traffic. To support energy transportation and provide safe roads, the reservation needs cost-efficient and effective transportation pla...

The rise of the mesopredator

USDA-ARS?s Scientific Manuscript database

Apex predators have experienced catastrophic declines throughout the world due to human persecution and habitat loss. These collapses in top predator populations are commonly associated with dramatic increases in the abundance of smaller predators. Known as ‘mesopredator release,’ this trophic inte...

Ordered polymer nanofibers enhance output brightness in bilayer light-emitting field-effect transistors.

PubMed

Hsu, Ben B Y; Seifter, Jason; Takacs, Christopher J; Zhong, Chengmei; Tseng, Hsin-Rong; Samuel, Ifor D W; Namdas, Ebinazar B; Bazan, Guillermo C; Huang, Fei; Cao, Yong; Heeger, Alan J

2013-03-26

Polymer light emitting field effect transistors are a class of light emitting devices that reveal interesting device physics. Device performance can be directly correlated to the most fundamental polymer science. Control over surface properties of the transistor dielectric can dramatically change the polymer morphology, introducing ordered phase. Electronic properties such as carrier mobility and injection efficiency on the interface can be promoted by ordered nanofibers in the polymer. Moreover, by controlling space charge in the polymer interface, the recombination zone can be spatially extended and thereby enhance the optical output.

Spine oncology: Daedalus, Theseus, and the Minotaur.

PubMed

Donthineni, Rakesh; Ofluoglu, Onder

2009-01-01

Over the past three decades, progress has been dramatic in the management of spine tumors. For example, advanced imaging technologies made available at manageable costs have lowered the threshold for scanning. CT, MRI, and PET imaging modalities have greatly enhanced the ability of the surgeon to accurately delineate the extension of the lesion within the bone, the soft tissue, and the spinal canal. Such enhancements have led to great leaps forward in preoperative planning and postoperative evaluation, including improved reconstruction options are resulting in improved outcomes. This article introduces the theme of this volume.

NOK mediates glycolysis and nuclear PDC associated histone acetylation.

PubMed

Shi, Wei-Ye; Yang, Xiao; Huang, Bo; Shen, Wen H; Liu, Li

2017-06-01

NOK is a potent oncogene that can transform normal cells to cancer cells. We hypothesized that NOK might impact cancer cell metabolism and histone acetylation. We show that NOK localizes in the mitochondria, and while it minimally impacts tricarboxylic acid (TCA) cycle, it markedly inhibits the process of electron transport and oxidative phosphorylation processes and dramatically enhances aerobic glycolysis in cancer cells. NOK promotes the mitochondrial-nuclear translocation of pyruvate dehydrogenase complex (PDC), and enhances histone acetylation in the nucleus. Together, these findings show that NOK mediates glycolysis and nuclear PDC associated histone acetylation.

Layers of 'Cape Verde' in 'Victoria Crater' (False Color)

NASA Technical Reports Server (NTRS)

2006-01-01

This view of Victoria crater is looking north from 'Duck Bay' towards the dramatic promontory called 'Cape Verde.' The dramatic cliff of layered rocks is about 50 meters (about 165 feet) away from the rover and is about 6 meters (about 20 feet) tall. The taller promontory beyond that is about 100 meters (about 325 feet) away, and the vista beyond that extends away for more than 400 meters (about 1300 feet) into the distance. This is an enhanced false color rendering of images taken by the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity during the rover's 952nd sol, or Martian day, (Sept. 28, 2006) using the camera's 750-nanometer, 530-nanometer and 430-nanometer filters.

A Dramatic Regime Shift in Rainfall Predictability Related to the Ningaloo Niño/Niña in the Late 1990s

NASA Astrophysics Data System (ADS)

Doi, T.; Behera, S. K.; Yamagata, T.

2014-12-01

The global warming and the Interdecadal Pacific Oscillation (IPO) started influencing the coastal ocean off Western Australia, leading to a dramatic change in the regional climate predictability.　The warmed ocean started driving rainfall regionally there after the late 1990s. Because of this, rainfall predictability off Western Australia on a seasonal time scale was drastically enhanced in the late 1990s; it is significantly predictable 5 months ahead after the late 1990s. The high prediction skill of the rainfall in recent decades encourages development of an early warning system of Ningaloo Niño/Niña events to mitigate possible societal as well as agricultural impacts in the granary.

Enhancement of IVR images by combining an ICA shrinkage filter with a multi-scale filter

NASA Astrophysics Data System (ADS)

Chen, Yen-Wei; Matsuo, Kiyotaka; Han, Xianhua; Shimizu, Atsumoto; Shibata, Koichi; Mishina, Yukio; Mukuta, Yoshihiro

2007-11-01

Interventional Radiology (IVR) is an important technique to visualize and diagnosis the vascular disease. In real medical application, a weak x-ray radiation source is used for imaging in order to reduce the radiation dose, resulting in a low contrast noisy image. It is important to develop a method to smooth out the noise while enhance the vascular structure. In this paper, we propose to combine an ICA Shrinkage filter with a multiscale filter for enhancement of IVR images. The ICA shrinkage filter is used for noise reduction and the multiscale filter is used for enhancement of vascular structure. Experimental results show that the quality of the image can be dramatically improved without any blurring in edge by the proposed method. Simultaneous noise reduction and vessel enhancement have been achieved.

Joint denoising, demosaicing, and chromatic aberration correction for UHD video

NASA Astrophysics Data System (ADS)

Jovanov, Ljubomir; Philips, Wilfried; Damstra, Klaas Jan; Ellenbroek, Frank

2017-09-01

High-resolution video capture is crucial for numerous applications such as surveillance, security, industrial inspection, medical imaging and digital entertainment. In the last two decades, we are witnessing a dramatic increase of the spatial resolution and the maximal frame rate of video capturing devices. In order to achieve further resolution increase, numerous challenges will be facing us. Due to the reduced size of the pixel, the amount of light also reduces, leading to the increased noise level. Moreover, the reduced pixel size makes the lens imprecisions more pronounced, which especially applies to chromatic aberrations. Even in the case when high quality lenses are used some chromatic aberration artefacts will remain. Next, noise level additionally increases due to the higher frame rates. To reduce the complexity and the price of the camera, one sensor captures all three colors, by relying on Color Filter Arrays. In order to obtain full resolution color image, missing color components have to be interpolated, i.e. demosaicked, which is more challenging than in the case of lower resolution, due to the increased noise and aberrations. In this paper, we propose a new method, which jointly performs chromatic aberration correction, denoising and demosaicking. By jointly performing the reduction of all artefacts, we are reducing the overall complexity of the system and the introduction of new artefacts. In order to reduce possible flicker we also perform temporal video enhancement. We evaluate the proposed method on a number of publicly available UHD sequences and on sequences recorded in our studio.

A young-onset frontal dementia with dramatic calcifications due to a novel CSF1R mutation.

PubMed

Gore, Ethan; Manley, Andrew; Dees, Daniel; Appleby, Brian S; Lerner, Alan J

2016-06-01

Neuroimaging and genomic analysis greatly aid in the identification of young-onset dementia antemortem. We present the case of a 33-year-old female with a 2-year rapid decline to dementia and immobility marked by personality change, executive deficits including compulsions, attention deficit, apraxia, Parkinsonism, and pyramidal signs. She had unique and dramatic calcifications and confluent white matter changes on imaging and was found to have a novel mutation in the colony stimulating factor 1 receptor gene causing adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP). Here, we review ALSP and briefly discuss differential diagnoses.

Transgenic plants with enhanced growth characteristics

DOEpatents

Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

2016-09-06

The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

Enhancement of capacitance benefit by drain offset structure in tunnel field-effect transistor circuit speed associated with tunneling probability increase

NASA Astrophysics Data System (ADS)

Asai, Hidehiro; Mori, Takahiro; Matsukawa, Takashi; Hattori, Junichi; Endo, Kazuhiko; Fukuda, Koichi

2018-04-01

The effect of a drain offset structure on the operation speed of a tunnel field-effect transistor (TFET) ring oscillator is investigated by technology computer-aided design (TCAD) simulation. We demonstrate that the reduction of gate-drain capacitance by the drain offset structure dramatically increases the operation speed of the ring oscillators. Interestingly, we find that this capacitance benefit to operation speed is enhanced by the increase in band-to-band tunneling probability. The “synergistic” speed enhancement by the drain offset structure and the tunneling rate increase will have promising application to the significant improvement of the operation speed of TFET circuits.

The effects of everolimus on tuberous sclerosis-associated lesions can be dramatic but may be impermanent.

PubMed

Miller, Joseph M; Wachsman, Ashley; Haker, Katherine; Majlessipour, Fataneh; Danielpour, Moise; Puliyanda, Dechu

2015-01-01

Tuberous sclerosis complex (TSC) predisposes to the development of benign lesions within multiple organ systems, including the brain, kidneys, heart, lungs, and skin. Disease mortality is due to space-occupying subependymal giant cell astrocytomas and hemorrhage-prone renal angiomyolipomas. The recent use of mTORC1 inhibitors, such as everolimus, has allowed for direct targeting of TSC-associated mass lesions without apparent effect on surrounding tissues. Because of the mechanism of these drugs, there is reason to believe that these effects are not durable and that there may be need for continued long-term maintenance therapy. We present a case of TSC-associated mass lesions that were ill-suited for definitive surgical therapy. The patient was started on everolimus, however due to a complex social situation treatment was discontinued and ultimately resumed many months later. Radiologic studies acquired before and after each period of therapeutic onset/cessation reveal the dramatic but impermanent effects of mTORC1 inhibition. While everolimus provides a non-invasive way to treat TSC-associated lesions, patients may require lifelong therapy. When termination of therapy is considered, the patient should be made aware of the expectation of potentially dramatic increases in lesion size. If consideration is to be given to definitive surgical therapy, it should be pursued while the patient is still on the medication, or at least soon after treatment is halted.

Plasma characteristics of direct current enhanced cylindrical inductively coupled plasma source

NASA Astrophysics Data System (ADS)

Yue, HUA; Jian, SONG; Zeyu, HAO; Chunsheng, REN

2018-06-01

Experimental results of a direct current enhanced inductively coupled plasma (DCE-ICP) source which consists of a typical cylindrical ICP source and a plate-to-grid DC electrode are reported. With the use of this new source, the plasma characteristic parameters, namely, electron density, electron temperature and plasma uniformity, are measured by Langmuir floating double probe. It is found that DC discharge enhances the electron density and decreases the electron temperature, dramatically. Moreover, the plasma uniformity is obviously improved with the operation of DC and radio frequency (RF) hybrid discharge. Furthermore, the nonlinear enhancement effect of electron density with DC + RF hybrid discharge is confirmed. The presented observation indicates that the DCE-ICP source provides an effective method to obtain high-density uniform plasma, which is desirable for practical industrial applications.

Improving the Student Experience: A Practical Guide for Universities and Colleges

ERIC Educational Resources Information Center

Morgan, Michelle, Ed.

2011-01-01

The landscape of higher education (HE) has dramatically altered in the past 30 years and it continues to evolve and change. More students are entering HE and attending university or college on a global scale than ever before. Supporting and enhancing the undergraduate student experience across the student lifecycle, from first contact through to…

The Engineer of 2020: Visions of Engineering in the New Century

ERIC Educational Resources Information Center

National Academies Press, 2004

2004-01-01

To enhance the nation's economic productivity and improve the quality of life worldwide, engineering education in the United States must anticipate and adapt to the dramatic changes of engineering practice. The Engineer of 2020 urges the engineering profession to recognize what engineers can build for the future through a wide range of leadership…

Moving in the Right Direction but at What Speed, and How Smoothly?

ERIC Educational Resources Information Center

Deshler, Donald D.

2015-01-01

In this article, I describe two of our field's most notable advancements for students with high-incidence disabilities. The first has been to enhance our knowledge of how to design effective instructional interactions between teachers and students (in both small and large groups) that lead to dramatic increases in student outcomes. The second area…

Anthropometric Evaluations of Body Composition of Undergraduate Students at the University of La Reunion

ERIC Educational Resources Information Center

Tarnus, Evelyne; Bourdon, Emmanuel

2006-01-01

A positive correlation is well established between obesity and the susceptibility to develop metabolic syndrome, a multifactorial disease dramatically associated with an enhanced mortality risk in the developed world. A high prevalence of obesity has recently been described at La Reunion Island, a French department in the Indian Ocean.…

Initial Results of a New Clinical Practice Model: Impact on Learners at Risk

ERIC Educational Resources Information Center

Wasburn-Moses, Leah; Noltemeyer, Amity L.; Schmitz, Kristin J.

2015-01-01

The last several years have seen a dramatic increase in interest surrounding the role of clinical experiences in enhancing the learning of teacher candidates. Further, pressure has intensified to demonstrate the impact of teacher candidates on P-12 learners. With these goals in mind, a model alternative school/university partnership was created,…

Responding to Changes in HIV Policy: Updating and Enhancing the "Families Matter!" Curriculum

ERIC Educational Resources Information Center

Miller, Kim S; Winskell, Kate; Berrier, Faith L

2016-01-01

Objectives: The past decade has seen changes in US HIV policy in sub-Saharan Africa in response to a new Administration and far-reaching technical, scientific and programmatic developments. These include dramatically increased access to life-saving anti-retroviral therapy (ART) and related services, the roll-out of voluntary medical male…

Exploring the Glycemic Response to Food Intake with Undergraduate Students at the University of La Reunion

ERIC Educational Resources Information Center

Tarnus, Evelyne; Bourdon, Emmanuel

2008-01-01

Diabetes constitutes an increasingly prevalent disease, dramatically associated with an enhanced mortality risk in the developed world. A high prevalence of diabetes has recently been described at Reunion Island, a French department located in the Indian Ocean. At the University of La Reunion, a laboratory course involving students was designed to…

Using Creative Dramatics to Foster Conceptual Learning in a Science Enrichment Program

ERIC Educational Resources Information Center

Hendrix, Rebecca Compton

2011-01-01

This study made analysis of how the integration of creative drama into a science enrichment program enhanced the learning of elementary school students' understanding of sound physics and solar energy. The study also sought to determine if student attitudes toward science could be improved with the inclusion of creative drama as an extension…

Enhanced inflammation and attenuated tumor suppressor pathways are associated with oncogene-induced lung tumors in aged mice

USDA-ARS?s Scientific Manuscript database

Aging is often accompanied by a dramatic increase in cancer susceptibility. To gain insights into how aging affects tumor susceptibility, we generated a conditional mouse model in which oncogenic KrasG12D was activated specifically in lungs of young (3-5 months) and old (19-24 months) mice. Activati...

Using the Story of Cinderella To Teach the Major Approaches to Treatment and Therapy.

ERIC Educational Resources Information Center

Kaminski, Patricia L.; Haynes, Sandra D.

2000-01-01

Describes a classroom activity to enhance understanding of how major theorists differ in their conceptualization and treatment of a client's problems. Participants either watched a dramatized play in which prominent clinicians discuss a case, or attended a comparable lecture. Results of a quiz indicate that students who watched the play…

Enhancing the Resilience of Young Single Mothers of Color: A Review of Programs and Services

ERIC Educational Resources Information Center

Romo, Laura F.; Segura, Denise A.

2010-01-01

Within the last decade, births to unmarried women in the United States have risen dramatically, presenting challenges for young women to complete high school and attend college. This article presents a review of programs and services designed to support single mothers in completing high school and accessing postsecondary education. We highlight…

Singlet oxygen generation of photosensitizers effectively activated by Nd3+-doped upconversion nanoparticles of luminescence intensity enhancing with shell thickness decreasing

NASA Astrophysics Data System (ADS)

Zou, Haixia; Jin, Fengmin; Song, Xiaoyan; Xing, Jinfeng

2017-04-01

The introduction of a thick shell structure has been widely used to enhance the emission intensity of upconversion nanoparticles (UCNPs). However, a thick shell could increase the distance between UCNPs and photosensitizers, which is not favourable to the generation of singlet oxygen (1O2) in photodynamic therapy (PDT) due to the low fluorescence resonance energy transfer (FRET) efficiency. In this study, we used a facile method to prepare UCNPs that the emission intensity could increase with the shell thickness decreasing, which facilitated the efficient FRET between UCNPs and photosensitizers. In detail, the Nd3+-doped UCNPs with different dopant concentration of Yb3+ were prepared and characterized firstly. The Ir/g (intensity of red luminescence to green luminescence) was tuned to increase largely by precisely controlling Yb3+ concentration in core-shell, which could make UCNPs effectively activate methylene blue (MB). Then, a unique procedure was used to prepare NaYF4:Yb/Er/Nd@NaYF4:Nd (Yb3+:30%) core-shell nanoparticles with different shell thickness by tuning the amount of the core. The upconversion luminescence (UCL) intensity of those UCNPs enhanced dramatically with the shell thickness decreasing. Furthermore, UCNPs and MB were encapsulated into SiO2 nanoparticles. FRET efficiency between UCNPs and MB largely increased with the shell thickness of UCNPs decreasing. Correspondingly, the efficiency of 1O2 generation obviously increased. We provided a new method to optimize the UCL intensity and FRET efficiency at the same time to produce 1O2 efficiently.

Precise Regulation of miR-210 Is Critical for the Cellular Homeostasis Maintenance and Transplantation Efficacy Enhancement of Mesenchymal Stem Cells in Acute Liver Failure Therapy.

PubMed

Liu, Yingxia; Xiong, Yongjia; Xing, Feiyue; Gao, Hao; Wang, Xiaogang; He, Liumin; Ren, Chaoran; Liu, Lei; So, Kwok-Fai; Xiao, Jia

2017-05-09

Stem cell transplantation is a promising clinical strategy to cure acute liver failure. However, a low cell survival ratio after transplantation significantly impairs its therapeutic efficacy. This is partly due to insufficient resistance of transplanted stem cells to severe oxidative and inflammatory stress at the injury sites. In the current study, we demonstrated that a small molecule zeaxanthin dipalmitate (ZD) could enhance the defensive abilities against adverse stresses of human adipose-derived mesenchymal stem cells (hADMSCs) in vitro and increase their therapeutic outcomes of acute liver failure after transplantation in vivo. Treatment with ZD dramatically improved cell survival and suppressed apoptosis, inflammation, and reactive oxygen species (ROS) production of hADMSCs through the PKC/Raf-1/MAPK/NF-κB pathway to maintain a reasonably high expression level of microRNA-210 (miR-210). The regulation loop between miR-210 and cellular/mitochondrial ROS production was found to be linked by the ROS inhibitor iron-sulfur cluster assembly proteins (ISCU). Pretreatment with ZD and stable knockdown of miR-210 significantly improved and impaired the stem cell transplantation efficacy through the alteration of hepatic cell expansion and injury amelioration, respectively. Vehicle treatment with ZD did not pose any adverse effect on cell homeostasis or healthy animal. In conclusion, elevating endogenous antioxidant level of hADMSCs with ZD significantly enhances their hepatic tissue-repairing capabilities. Maintenance of a physiological level of miR-210 is critical for hADMSC homeostasis.

Structural development of human brain white matter from mid-fetal to perinatal stage

NASA Astrophysics Data System (ADS)

Ouyang, Austin; Yu, Qiaowen; Mishra, Virendra; Chalak, Lina; Jeon, Tina; Sivarajan, Muraleedharan; Jackson, Greg; Rollins, Nancy; Liu, Shuwei; Huang, Hao

2015-03-01

The structures of developing human brain white matter (WM) tracts can be effectively quantified by DTI-derived metrics, including fractional anisotropy (FA), mean, axial and radial diffusivity (MD, AD and RD). However, dynamics of WM microstructure during very early developmental period from mid-fetal to perinatal stage is unknown. It is difficult to accurately measure microstructural properties of these WM tracts due to severe contamination from cerebrospinal fluid (CSF). In this study, high resolution DTI of fetal brains at mid-fetal stage (20 weeks of gestation or 20wg), 19 brains in the middle of 3rd trimester (35wg) and 17 brains around term (40wg) were acquired. We established first population-averaged DTI templates at these three time points and extracted WM skeleton. 16 major WM tracts in limbic, projection, commissural and association tract groups were traced with DTI tractography in native space. The WM skeleton in the template space was inversely transformed back to the native space for measuring core WM microstructures of each individual tract. Continuous microstructural enhancement and volumetric increase of WM tracts were found from 20wg to 40wg. The microstructural enhancement from FA measurement is decelerated in late 3rd trimester compared to mid-fetal to middle 3rd trimester, while volumetric increase of prefrontal WM tracts is accelerated. The microstructural enhancement from 35wg to 40wg is heterogeneous among different tract groups with microstructures of association tracts undergoing most dramatic change. Besides decreases of RD indicating active myelination, the decrease of AD for most WM tracts during late 3rd trimester suggests axonal packing process.

Causes and Prevention of Structural Materials Failures in Naval Environments.

DTIC Science & Technology

1984-01-01

atomic hydrogen as the first step; (iii) creation of elastic-plastic zones near the crack tip region due to movement of dislocations under applied...sodium tellurate is added to the charging solution. There is a dramatic drop in hydrogen permeation current due to the reduction of the tellurate ...effect of tellurium which has been deposited. Thus it has been shown that the tellurate ion, an electron acceptor, can delay the production of hydrogen

Bioengineered nisin derivatives with enhanced activity in complex matrices

PubMed Central

Rouse, Susan; Field, Des; Daly, Karen M.; O'Connor, Paula M.; Cotter, Paul D.; Hill, Colin; Ross, R. Paul

2012-01-01

Summary Nisin A is the best known and most extensively characterized lantibiotic. As it is ribosomally synthesized, bioengineering‐based strategies can be used to generate variants. We have previously demonstrated that bioengineering of the hinge region of nisin A can result in the generation of variants with enhanced anti‐microbial activity against Gram‐positive pathogens. Here we created a larger bank of hinge variant producers and screened for producers that exhibit enhanced bioactivity as assessed by agar‐based assays against a selection of target strains. Further analysis of 12 ‘lead’ variants reveals that in many cases enhanced bioactivity is not attributable to enhanced specific activity but is instead as a consequence of an enhanced ability to diffuse through complex polymers. In the case of two variants, which contain the residues SVA and NAK, respectively, within the hinge region, we demonstrate that this enhanced trait enables the peptides to dramatically outperform nisin A with respect to controlling Listeria monocytogenes in commercially produced chocolate milk that contains carrageenan as a stabilizer. PMID:22260415

Cannabis, Cannabinoids, and Cerebral Metabolism: Potential Applications in Stroke and Disorders of the Central Nervous System.

PubMed

Latorre, Julius Gene S; Schmidt, Elena B

2015-09-01

No compound has generated more attention in both the scientific and recently in the political arena as much as cannabinoids. These diverse groups of compounds referred collectively as cannabinoids have both been vilified due to its dramatic and potentially harmful psychotropic effects and glorified due to its equally dramatic and potential application in a number of acute and chronic neurological conditions. Previously illegal to possess, cannabis, the plant where natural form of cannabinoids are derived, is now accepted in a growing number of states for medicinal purpose, and some even for recreational use, increasing opportunities for more scientific experimentation. The purpose of this review is to summarize the growing body of literature on cannabinoids and to present an overview of our current state of knowledge of the human endocannabinoid system in the hope of defining the future of cannabinoids and its potential applications in disorders of the central nervous system, focusing on stroke.

Surface-enhanced Raman scattering from graphene covered gold nanocap arrays

NASA Astrophysics Data System (ADS)

Long, Kailin; Luo, Xiaoguang; Nan, Haiyan; Du, Deyang; Zhao, Weiwei; Ni, Zhenhua; Qiu, Teng

2013-11-01

This work reports an efficient method to fabricate large-area flexible substrates for surface enhanced Raman scattering (SERS) application. Our technique is based on a single-step direct imprint process via porous anodic alumina stamps. Periodic hexagonal arrangements of porous anodic alumina stamps are transferred to the polyethylene terephthalate substrates by mechanically printing process. Printed nanocaps will turn into "hot spots" for electromagnetic enhancement with a deposited gold film by high vacuum evaporation. The gaps between the nanocaps are controllable with a tight correspondence to the thickness of the deposited gold, which dramatically influence the enhancement factor. After covered with a single-layer graphene sheet, the gold nanocap substrate can be further optimized with an extra enhancement of Raman signals, and it is available for the trace detection of probe molecules. This convenient, simple, and low-cost method of making flexible SERS-active substrates potentially opens a way towards biochemical analysis and disease detection.

Enhanced magneto-optical Kerr effect at Fe/insulator interfaces

NASA Astrophysics Data System (ADS)

Gu, Bo; Takahashi, Saburo; Maekawa, Sadamichi

2017-12-01

Using density functional theory calculations, we have found an enhanced magneto-optical Kerr effect in Fe/insulator interfaces. The results of our study indicate that interfacial Fe atoms in the Fe films have a low-dimensional nature, which causes the following two effects: (i) The diagonal component σx x of the optical conductivity decreases dramatically because the hopping integral for electrons between Fe atoms is suppressed by the low dimensionality. (ii) The off-diagonal component σx y of the optical conductivity does not change at low photon energies, but it is enhanced at photon energies around 2 eV, where we obtain enhanced orbital magnetic moments and spin-orbit correlations for the interfacial Fe atoms. A large Kerr angle develops in proportion to the ratio σx y/σx x . Our findings indicate an efficient way to enhance the effect of spin-orbit coupling at metal/insulator interfaces without using heavy elements.

Highly sensitive surface-enhanced Raman scattering substrate made from superaligned carbon nanotubes.

PubMed

Sun, Yinghui; Liu, Kai; Miao, Jiao; Wang, Zheyao; Tian, Baozhong; Zhang, Lina; Li, Qunqing; Fan, Shoushan; Jiang, Kaili

2010-05-12

Surface-enhanced Raman scattering (SERS) has attracted wide attention because it can enhance normally weak Raman signal by several orders of magnitude and facilitate the sensitive detection of molecules. Conventional SERS substrates are constructed by placing metal nanoparticles on a planar surface. Here we show that, if the planar surface was substituted by a unique nanoporous surface, the enhancement effect can be dramatically improved. The nanoporous surface can be easily fabricated in batches and at low costs by cross stacking superaligned carbon nanotube films. The as-prepared transparent and freestanding SERS substrate is capable of detecting ambient trinitrotoluene vapor, showing much higher Raman enhancement than ordinary planar substrates because of the extremely large surface area and the unique zero-dimensional at one-dimensional nanostructure. These results not only provide a new approach to ultrasensitive SERS substrates, but also are helpful for improving the fundamental understanding of SERS phenomena.

Engineering Enhanced Vaccine Cell Lines To Eradicate Vaccine-Preventable Diseases: the Polio End Game.

PubMed

van der Sanden, Sabine M G; Wu, Weilin; Dybdahl-Sissoko, Naomi; Weldon, William C; Brooks, Paula; O'Donnell, Jason; Jones, Les P; Brown, Cedric; Tompkins, S Mark; Oberste, M Steven; Karpilow, Jon; Tripp, Ralph A

2016-02-15

Vaccine manufacturing costs prevent a significant portion of the world's population from accessing protection from vaccine-preventable diseases. To enhance vaccine production at reduced costs, a genome-wide RNA interference (RNAi) screen was performed to identify gene knockdown events that enhanced poliovirus replication. Primary screen hits were validated in a Vero vaccine manufacturing cell line using attenuated and wild-type poliovirus strains. Multiple single and dual gene silencing events increased poliovirus titers >20-fold and >50-fold, respectively. Host gene knockdown events did not affect virus antigenicity, and clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9-mediated knockout of the top candidates dramatically improved viral vaccine strain production. Interestingly, silencing of several genes that enhanced poliovirus replication also enhanced replication of enterovirus 71, a clinically relevant virus to which vaccines are being targeted. The discovery that host gene modulation can markedly increase virus vaccine production dramatically alters mammalian cell-based vaccine manufacturing possibilities and should facilitate polio eradication using the inactivated poliovirus vaccine. Using a genome-wide RNAi screen, a collection of host virus resistance genes was identified that, upon silencing, increased poliovirus and enterovirus 71 production by from 10-fold to >50-fold in a Vero vaccine manufacturing cell line. This report provides novel insights into enterovirus-host interactions and describes an approach to developing the next generation of vaccine manufacturing through engineered vaccine cell lines. The results show that specific gene silencing and knockout events can enhance viral titers of both attenuated (Sabin strain) and wild-type polioviruses, a finding that should greatly facilitate global implementation of inactivated polio vaccine as well as further reduce costs for live-attenuated oral polio vaccines. This work describes a platform-enabling technology applicable to most vaccine-preventable diseases. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Enhanced UV light detection using a p-terphenyl wavelength shifter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joosten, Sylvester J.; Kaczanowicz, Ed; Ungaro, Maurizio

Here, UV-glass photomultiplier tubes (PMTs) have poor photon detection efficiency for wavelengths belowmore » $$300\\,\\text{nm}$$ due to the opaqueness of the window material. Costly quartz PMTs could be used to enhance the efficiency below $$300\\,\\text{nm}$$. A less expensive solution that dramatically improves this efficiency is the application of a thin film of a p-terphenyl (PT) wavelength shifter on UV-glass PMTs. This improvement was quantified for Photonis XP4500B PMTs for wavelengths between $$200\\,\\text{nm}$$ and $$400\\,\\text{nm}$$. The gain factor ranges up to 5.4 $$\\pm$$ 0.5 at a wavelength of $$215\\,\\text{nm}$$, with a material load of $$110\\pm10\\,\\mu\\text{g}/\\text{cm}^2$$ ($$894\\,\\text{nm}$$). The wavelength shifter was found to be fully transparent for wavelengths greater than $$300\\,\\text{nm}$$. The resulting gain in detection efficiency, when used in a typical Cherenkov counter, was estimated to be of the order of 40%. Consistent coating quality was assured by a rapid gain testing procedure using narrow-band UV LEDs. Based on these results, 200 Photonis XP4500B PMTs were treated with PT for the upgraded low-threshold Cherenkov counter (LTCC) to be used in the CEBAF Large Acceptance Spectrometer upgraded detector (CLAS12) at the Thomas Jefferson National Accelerator Facility.« less

Advanced Li-Ion Hybrid Supercapacitors Based on 3D Graphene-Foam Composites.

PubMed

Liu, Wenwen; Li, Jingde; Feng, Kun; Sy, Abel; Liu, Yangshuai; Lim, Lucas; Lui, Gregory; Tjandra, Ricky; Rasenthiram, Lathankan; Chiu, Gordon; Yu, Aiping

2016-10-05

Li-ion hybrid supercapacitors (LIHSs) have recently attracted increasing attention as a new and promising energy storage device. However, it is still a great challenge to construct novel LIHSs with high-performance due to the majority of battery-type anodes retaining the sluggish kinetics of Li-ion storage and most capacitor-type cathodes with low specific capacitance. To solve this problem, 3D graphene-wrapped MoO 3 nanobelt foam with the unique porous network structure has been designed and prepared as anode material, which delivers high capacity, improved rate performance, and enhanced cycle stability. First-principles calculation reveals that the combination of graphene dramatically reduces the diffusion energy barrier of Li + adsorbed on the surface of MoO 3 nanobelt, thus improving its electrochemical performance. Furthermore, 3D graphene-wrapped polyaniline nanotube foam derived carbon is employed as a new type of capacitor-type cathode, demonstrating high specific capacitance, good rate performance, and long cycle stability. Benefiting from these two graphene foam-enhanced materials, the constructed LIHSs show a wide operating voltage range (3.8 V), a long stable cycle life (90% capacity retention after 3000 cycles), a high energy density (128.3 Wh·kg -1 ), and a high power density (13.5 kW·kg -1 ). These encouraging performances indicate that the obtained LIHSs may have promising prospect as next-generation energy-storage devices.

Enhanced thermoelectric performance driven by high-temperature phase transition in the phase change material Ge 4SbTe 5

DOE PAGES

Williams, Jared B.; Lara-Curzio, Edgar; Cakmak, Ercan; ...

2015-05-15

Phase change materials are identified for their ability to rapidly alternate between amorphous and crystalline phases and have large contrast in the optical/electrical properties of the respective phases. The materials are primarily used in memory storage applications, but recently they have also been identified as potential thermoelectric materials. Many of the phase change materials researched today can be found on the pseudo-binary (GeTe) 1-x(Sb 2Te 3) x tie-line. While many compounds on this tie-line have been recognized as thermoelectric materials, here we focus on Ge 4SbTe 5, a single phase compound just off of the (GeTe) 1-x(Sb 2Te 3) xmore » tie-line, that forms in a stable rocksalt crystal structure at room temperature. We find that stoichiometric and undoped Ge 4SbTe 5 exhibits a thermal conductivity of ~1.2 W/m-K at high temperature and a large Seebeck coefficient of ~250 μV/K. The resistivity decreases dramatically at 623 K due to a structural phase transition which lends to a large enhancement in both thermoelectric power factor and thermoelectric figure of merit at 823 K. In a more general sense the research presents evidence that phase change materials can potentially provide a new route to highly efficient thermoelectric materials for power generation at high temperature.« less

PANTHER version 11: expanded annotation data from Gene Ontology and Reactome pathways, and data analysis tool enhancements.

PubMed

Mi, Huaiyu; Huang, Xiaosong; Muruganujan, Anushya; Tang, Haiming; Mills, Caitlin; Kang, Diane; Thomas, Paul D

2017-01-04

The PANTHER database (Protein ANalysis THrough Evolutionary Relationships, http://pantherdb.org) contains comprehensive information on the evolution and function of protein-coding genes from 104 completely sequenced genomes. PANTHER software tools allow users to classify new protein sequences, and to analyze gene lists obtained from large-scale genomics experiments. In the past year, major improvements include a large expansion of classification information available in PANTHER, as well as significant enhancements to the analysis tools. Protein subfamily functional classifications have more than doubled due to progress of the Gene Ontology Phylogenetic Annotation Project. For human genes (as well as a few other organisms), PANTHER now also supports enrichment analysis using pathway classifications from the Reactome resource. The gene list enrichment tools include a new 'hierarchical view' of results, enabling users to leverage the structure of the classifications/ontologies; the tools also allow users to upload genetic variant data directly, rather than requiring prior conversion to a gene list. The updated coding single-nucleotide polymorphisms (SNP) scoring tool uses an improved algorithm. The hidden Markov model (HMM) search tools now use HMMER3, dramatically reducing search times and improving accuracy of E-value statistics. Finally, the PANTHER Tree-Attribute Viewer has been implemented in JavaScript, with new views for exploring protein sequence evolution. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Flame oxidation of stainless steel felt enhances anodic biofilm formation and current output in bioelectrochemical systems.

PubMed

Guo, Kun; Donose, Bogdan C; Soeriyadi, Alexander H; Prévoteau, Antonin; Patil, Sunil A; Freguia, Stefano; Gooding, J Justin; Rabaey, Korneel

2014-06-17

Stainless steel (SS) can be an attractive material to create large electrodes for microbial bioelectrochemical systems (BESs), due to its low cost and high conductivity. However, poor biocompatibility limits its successful application today. Here we report a simple and effective method to make SS electrodes biocompatible by means of flame oxidation. Physicochemical characterization of electrode surface indicated that iron oxide nanoparticles (IONPs) were generated in situ on an SS felt surface by flame oxidation. IONPs-coating dramatically enhanced the biocompatibility of SS felt and consequently resulted in a robust electroactive biofilm formation at its surface in BESs. The maximum current densities reached at IONPs-coated SS felt electrodes were 16.5 times and 4.8 times higher than the untreated SS felts and carbon felts, respectively. Furthermore, the maximum current density achieved with the IONPs-coated SS felt (1.92 mA/cm(2), 27.42 mA/cm(3)) is one of the highest current densities reported thus far. These results demonstrate for the first time that flame oxidized SS felts could be a good alternative to carbon-based electrodes for achieving high current densities in BESs. Most importantly, high conductivity, excellent mechanical strength, strong chemical stability, large specific surface area, and comparatively low cost of flame oxidized SS felts offer exciting opportunities for scaling-up of the anodes for BESs.

Hydroxypropyl cyclic β-(1 → 2)-D-glucans and epichlorohydrin β-cyclodextrin dimers as effective carbohydrate-solubilizers for polycyclic aromatic hydrocarbons.

PubMed

Choi, Jae Min; Jeong, Daham; Piao, Jinglan; Kim, Kyoungtea; Nguyen, Andrew Bao Loc; Kwon, Nak-Jung; Lee, Mi-Kyung; Lee, Im Soon; Yu, Jae-Hyuk; Jung, Seunho

2015-01-12

The removal of polycyclic aromatic hydrocarbons by soil washing using water is extremely difficult due to their intrinsic hydrophobic nature. In this study, the effective aqueous solubility enhancements of seven polycyclic aromatic hydrocarbons by chemically modified hydroxypropyl rhizobial cyclic β-(1 → 2)-D-glucans and epichlorohydrin β-cyclodextrin dimer have been investigated for the first time. In the presence of hydroxypropyl cyclic β-(1 → 2)-D-glucans, the solubility of benzo[a]pyrene is increased up to 38 fold of its native solubility. The solubility of pyrene and phenanthrene dramatically increased up to 160 and 359. Coronene, chrysene, perylene, and fluoranthene also show an increase of 11, 23, 23, and 97 fold, respectively, of enhanced solubility by complexation with synthetic epichlorohydrin β-cyclodextrin dimer. The physicochemical properties of the complex are characterized by Fourier-transform infrared spectra and differential scanning calorimetry. Utilizing a scanning electron microscopy, the morphological structures of native benzo[a]pyrene, pyrene, phenanthrene, coronene, chrysene, perylene, fluoranthene and their complex with novel carbohydrate-solubilizers are studied. These results elucidate that polycyclic aromatic hydrocarbons are able to form an efficient complex with hydroxypropyl cyclic β-(1 → 2)-D-glucans and β-cyclodextrin dimer, suggesting the potential usage of chemically modified novel carbohydrate-solubilizers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Unique visible-light-assisted field emission of tetrapod-shaped ZnO/reduced graphene-oxide core/coating nanocomposites

PubMed Central

Wu, Chaoxing; Kim, Tae Whan; Guo, Tailiang; Li, Fushan

2016-01-01

The electronic and the optoelectronic properties of graphene-based nanocomposites are controllable, making them promising for applications in diverse electronic devices. In this work, tetrapod-shaped zinc oxide (T-ZnO)/reduced graphene oxide (rGO) core/coating nanocomposites were synthesized by using a hydrothermal-assisted self-assemble method, and their optical, photoelectric, and field-emission properties were investigated. The ZnO, an ideal ultraviolet-light-sensitive semiconductor, was observed to have high sensitivity to visible light due to the rGO coating, and the mechanism of that sensitivity was investigated. We demonstrated for the first time that the field-emission properties of the T-ZnO/rGO core/coating nanocomposites could be dramatically enhanced under visible light by decreasing the turn-on field from 1.54 to 1.41 V/μm and by increasing the current density from 5 to 12 mA/cm2 at an electric field of 3.5 V/μm. The visible-light excitation induces an electron jump from oxygen vacancies on the surface of ZnO to the rGO layer, resulting in a decrease in the work function of the rGO and an increase in the emission current. Furthermore, a field-emission light-emitting diode with a self-enhanced effect was fabricated making full use of the photo-assisted field-emission process. PMID:27941822

MXene-Based Electrode with Enhanced Pseudocapacitance and Volumetric Capacity for Power-Type and Ultra-Long Life Lithium Storage.

PubMed

Niu, Shanshan; Wang, Zhiyu; Yu, Mingliang; Yu, Mengzhou; Xiu, Luyang; Wang, Song; Wu, Xianhong; Qiu, Jieshan

2018-04-24

Powerful yet thinner lithium-ion batteries (LIBs) are eagerly desired to meet the practical demands of electric vehicles and portable electronic devices. However, the use of soft carbon materials in current electrode design to improve the electrode conductivity and stability does not afford high volumetric capacity due to their low density and capacity for lithium storage. Herein, we report a strategy leveraging the MXene with superior conductivity and density to soft carbon as matrix and additive material for comprehensively enhancing the power capability, lifespan, and volumetric capacity of conversion-type anode. A kinetics favorable 2D nanohybrid with high conductivity, compact density, accumulated pseudocapacitance, and diffusion-controlled behavior is fabricated by coupling Ti 3 C 2 MXene with high-density molybdenum carbide for fast lithium storage over 300 cycles with high capacities. By replacing the carbonaceous conductive agent with Ti 3 C 2 MXene, the electrodes with better conductivity and dramatically reduced thickens could be further manufactured to achieve 37-40% improvement in capacity retention and ultra-long life of 5500 cycles with extremely slow capacity loss of 0.002% per cycle at high current rates. Ultrahigh volumetric capacity of 2460 mAh cm -3 could be attained by such MXene-based electrodes, highlighting the great promise of MXene in the development of high-performance LIBs.

Reprogramming metabolism by targeting sirtuin 6 attenuates retinal degeneration

PubMed Central

Zhang, Lijuan; Du, Jianhai; Justus, Sally; Hsu, Chun-Wei; Bonet-Ponce, Luis; Wu, Wen-Hsuan; Tsai, Yi-Ting; Wu, Wei-Pu; Jia, Yading; Duong, Jimmy K.; Mahajan, Vinit B.; Lin, Chyuan-Sheng; Wang, Shuang; Hurley, James B.

2016-01-01

Retinitis pigmentosa (RP) encompasses a diverse group of Mendelian disorders leading to progressive degeneration of rods and then cones. For reasons that remain unclear, diseased RP photoreceptors begin to deteriorate, eventually leading to cell death and, consequently, loss of vision. Here, we have hypothesized that RP associated with mutations in phosphodiesterase-6 (PDE6) provokes a metabolic aberration in rod cells that promotes the pathological consequences of elevated cGMP and Ca2+, which are induced by the Pde6 mutation. Inhibition of sirtuin 6 (SIRT6), a histone deacetylase repressor of glycolytic flux, reprogrammed rods into perpetual glycolysis, thereby driving the accumulation of biosynthetic intermediates, improving outer segment (OS) length, enhancing photoreceptor survival, and preserving vision. In mouse retinae lacking Sirt6, effectors of glycolytic flux were dramatically increased, leading to upregulation of key intermediates in glycolysis, TCA cycle, and glutaminolysis. Both transgenic and AAV2/8 gene therapy–mediated ablation of Sirt6 in rods provided electrophysiological and anatomic rescue of both rod and cone photoreceptors in a preclinical model of RP. Due to the extensive network of downstream effectors of Sirt6, this study motivates further research into the role that these pathways play in retinal degeneration. Because reprogramming metabolism by enhancing glycolysis is not gene specific, this strategy may be applicable to a wide range of neurodegenerative disorders. PMID:27841758

A novel strategy to improve protein secretion via overexpression of the SppA signal peptide peptidase in Bacillus licheniformis.

PubMed

Cai, Dongbo; Wang, Hao; He, Penghui; Zhu, Chengjun; Wang, Qin; Wei, Xuetuan; Nomura, Christopher T; Chen, Shouwen

2017-04-24

Signal peptide peptidases play an important role in the removal of remnant signal peptides in the cell membrane, a critical step for extracellular protein production. Although these proteins are likely a central component for extracellular protein production, there has been a lack of research on whether protein secretion could be enhanced via overexpression of signal peptide peptidases. In this study, both nattokinase and α-amylase were employed as prototypical secreted target proteins to evaluate the function of putative signal peptide peptidases (SppA and TepA) in Bacillus licheniformis. We observed dramatic decreases in the concentrations of both target proteins (45 and 49%, respectively) in a sppA deficient strain, while the extracellular protein yields of nattokinase and α-amylase were increased by 30 and 67% respectively in a strain overexpressing SppA. In addition, biomass, specific enzyme activities and the relative gene transcriptional levels were also enhanced due to the overexpression of sppA, while altering the expression levels of tepA had no effect on the concentrations of the secreted target proteins. Our results confirm that SppA, but not TepA, plays an important functional role for protein secretion in B. licheniformis. Our results indicate that the sppA overexpression strain, B. licheniformis BL10GS, could be used as a promising host strain for the industrial production of heterologous secreted proteins.

Hydrogen Peroxide Activated Quinone Methide Precursors with Enhanced DNA Cross-Linking Capability and Cytotoxicity towards Cancer Cells

PubMed Central

Wang, Yibin; Fan, Heli; Balakrishnan, Kumudha; Lin, Zechao; Cao, Sheng; Chen, Wenbing; Fan, Yukai; Guthrie, Quibria A.; Sun, Huabing; Teske, Kelly A.; Gandhi, Varsha; Arnold, Leggy A.; Peng, Xiaohua

2017-01-01

Quinone methide (QM) formation induced by endogenously generated H2O2 is attractive for biological and biomedical applications. To overcome current limitations due to low biological activity of H2O2-activated QM precursors, we are introducing herein several new arylboronates with electron donating substituents at different positions of benzene ring and/or different neutral leaving groups. The reaction rate of the arylboronate esters with H2O2 and subsequent bisquinone methides formation and DNA cross-linking was accelerated with the application of Br as a leaving group instead of acetoxy groups. Additionally, a donating group placed meta to the nascent exo-methylene group of the quinone methide greatly improves H2O2-induced DNA interstrand cross-link formation as well as enhances the cellular activity. Multiple donating groups decrease the stability and DNA cross-linking capability, which lead to low cellular activity. A cell-based screen demonstrated that compounds 2a and 5a with a OMe or OH group dramatically inhibited the growth of various tissue-derived cancer cells while normal cells were less affected. Induction of H2AX phosphorylation by these compounds in CLL lymphocytes provide evidence for a correlation between cell death and DNA damage. The compounds presented herein showed potent anticancer activities and selectivity, which represent a novel scaffold for anticancer drug development. PMID:28388522

Measurement of photoemission and secondary emission from laboratory dust grains

NASA Technical Reports Server (NTRS)

Hazelton, Robert C.; Yadlowsky, Edward J.; Settersten, Thomas B.; Spanjers, Gregory G.; Moschella, John J.

1995-01-01

The overall goal of this project is experimentally determine the emission properties of dust grains in order to provide theorists and modelers with an accurate data base to use in codes that predict the charging of grains in various plasma environments encountered in the magnetospheres of the planets. In general these modelers use values which have been measured on planar, bulk samples of the materials in question. The large enhancements expected due to the small size of grains can have a dramatic impact upon the predictions and the ultimate utility of these predictions. The first experimental measurement of energy resolved profiles of the secondary electron emission coefficient, 6, of sub-micron diameter particles has been accomplished. Bismuth particles in the size range of .022 to .165 micrometers were generated in a moderate pressure vacuum oven (average size is a function of oven temperature and pressure) and introduced into a high vacuum chamber where they interacted with a high energy electron beam (0.4 to 20 keV). Large enhancements in emission were observed with a peak value, delta(sub max) = 4. 5 measured for the ensemble of particles with a mean size of .022 micrometers. This is in contrast to the published value, delta(sub max) = 1.2, for bulk bismuth. The observed profiles are in general agreement with recent theoretical predictions made by Chow et al. at UCSD.

Enhanced UV light detection using a p-terphenyl wavelength shifter

DOE PAGES

Joosten, Sylvester J.; Kaczanowicz, Ed; Ungaro, Maurizio; ...

2017-07-25

Here, UV-glass photomultiplier tubes (PMTs) have poor photon detection efficiency for wavelengths belowmore » $$300\\,\\text{nm}$$ due to the opaqueness of the window material. Costly quartz PMTs could be used to enhance the efficiency below $$300\\,\\text{nm}$$. A less expensive solution that dramatically improves this efficiency is the application of a thin film of a p-terphenyl (PT) wavelength shifter on UV-glass PMTs. This improvement was quantified for Photonis XP4500B PMTs for wavelengths between $$200\\,\\text{nm}$$ and $$400\\,\\text{nm}$$. The gain factor ranges up to 5.4 $$\\pm$$ 0.5 at a wavelength of $$215\\,\\text{nm}$$, with a material load of $$110\\pm10\\,\\mu\\text{g}/\\text{cm}^2$$ ($$894\\,\\text{nm}$$). The wavelength shifter was found to be fully transparent for wavelengths greater than $$300\\,\\text{nm}$$. The resulting gain in detection efficiency, when used in a typical Cherenkov counter, was estimated to be of the order of 40%. Consistent coating quality was assured by a rapid gain testing procedure using narrow-band UV LEDs. Based on these results, 200 Photonis XP4500B PMTs were treated with PT for the upgraded low-threshold Cherenkov counter (LTCC) to be used in the CEBAF Large Acceptance Spectrometer upgraded detector (CLAS12) at the Thomas Jefferson National Accelerator Facility.« less

Significant Enhancement of MgZnO Metal-Semiconductor-Metal Photodetectors via Coupling with Pt Nanoparticle Surface Plasmons

NASA Astrophysics Data System (ADS)

Guo, Zexuan; Jiang, Dayong; Hu, Nan; Yang, Xiaojiang; Zhang, Wei; Duan, Yuhan; Gao, Shang; Liang, Qingcheng; Zheng, Tao; Lv, Jingwen

2018-06-01

We proposed and demonstrated MgZnO metal-semiconductor-metal (MSM) ultraviolet photodetectors (UV) assisted with surface plasmons (SPs) prepared by the radio frequency magnetron sputtering deposition method. After the decoration of their surface with Pt nanoparticles (NPs), the responsivity of all the electrode spacing (3, 5, and 8 μm) photodetectors were enhanced dramatically; to our surprise, comparing with them the responsivity of larger spacing sample, more SPs were gathered which are smaller than others in turn. A physical mechanism focused on SPs and depletion width is given to explain the above results.

Folk Musics and Increasing Diversity in American Music Education, 1900-1916.

ERIC Educational Resources Information Center

Volk, Terese M.

1994-01-01

States that, from 1900-1916, U.S. demographic make-up changed dramatically due to the influx of people from southern and eastern Europe. Also asserts that some of the musics of African Americans and Native Americans were introduced into the music curriculum. (CFR)

Effects of calcium magnesium acetate, a road deicer, on the lentic environment in interior Alaska, interim report

DOT National Transportation Integrated Search

1985-03-01

The application of chloride deicing salts to roadways has increased dramatically in recent years due to public demand for safer winter driving conditions. Unfortunately, these salts create adverse effects such as corrosion of vehicles and bridge stru...

Taking lentils out of their comfort zone

USDA-ARS?s Scientific Manuscript database

Lentil is grown in many parts of the world where the photoperiod and temperature prior to flowering differ dramatically. Cultivars from one region struggle to perform well in other regions due to problems related to phenology. This makes breeders reluctant to use un-adapted material in their crosse...

On quantifying active soil carbon using mid-infrared spectroscopy

EPA Science Inventory

Soil organic matter (SOM) is derived from plant or animal residues deposited to soil and is in various stages of decomposition and mineralization. Total SOM is a common measure of soil quality, although due to its heterogeneous composition SOM can vary dramatically in terms of i...

Handedness Patterns in Autism Suggest Subtypes.

ERIC Educational Resources Information Center

Soper, Henry V.; And Others

1986-01-01

Preliminary data from two samples of autistic children and adults and an assessment procedure appropriate for lower-functioning autistic Ss revealed a dramatic shift away from right-handedness in both autistic samples, due to a raised incidence of two phenotypes: manifest left-handedness and ambiguous handedness. (Author/CL)

Freight transportation : short sea shipping option shows importance of systematic approach to public investment decisions : report to the Senate Committee on Commerce, Science, and Transportation and the House Committee on Transportation Infrastructure

DOT National Transportation Integrated Search

2005-07-01

A dramatic increase in freight moving on the nation's highways and rail lines, coupled with growing congestion and infrastructure limitations, has prompted DOT to explore new mobility-enhancing options like short sea shipping (SSS)--transporting frei...

Infrared imaging enhances retinal crystals in Bietti's crystalline dystrophy.

PubMed

Brar, Vikram S; Benson, William H

2015-01-01

Infrared imaging dramatically increased the number of crystalline deposits visualized compared with clinical examination, standard color fundus photography, and red free imaging in patients with Bietti's crystalline dystrophy. We believe that this imaging modality significantly improves the sensitivity with which these lesions are detected, facilitating earlier diagnosis and may potentially serve as a prognostic indicator when examined over time.

Influence of Problem-Based Learning Strategy on Enhancing Student's Industrial Oriented Competences Learned: An Action Research on Learning Weblog Analysis

ERIC Educational Resources Information Center

Chung, Pansy; Yeh, Ron Chuen; Chen, Yi-Cheng

2016-01-01

In order to respond to the ever-changing global economic environment, the technological and vocational education system in Taiwan needs to be dramatically reformed to the changing needs of the domestic industrial structure. Integrating practical talents with practical industrial experiences and competences can help avoid discrepancy and close the…

Education, Key to Economic Growth. Recent Major Education Initiatives in Support of Economic Development in New York State.

ERIC Educational Resources Information Center

New York State Education Dept., Albany.

This report describes new major education initiatives to enhance economic development in New York State. The 1970-1987 period has seen dramatic change in the labor profile impelled by technological and market forces transforming the economy. Apart from some fairly stable sectors, the state economy is characterized by a shift from manaufacturing to…

OpenCourseWare and Open Educational Resources: The Next Big Thing in Technology-Enhanced Education?

ERIC Educational Resources Information Center

Caudill, Jason G.

2012-01-01

OpenCourseWare (OCW) and Open Educational Resources (OER) are two new and closely related educational technologies. Both provide open access to learning materials for students and instructors via the Internet. These are for the moment still very young technologies. While they have grown dramatically in just ten years there is still relatively…

Conductive micropatterned polyurethane films as tissue engineering scaffolds for Schwann cells and PC12 cells.

PubMed

Wu, Yaobin; Wang, Ling; Hu, Tianli; Ma, Peter X; Guo, Baolin

2018-05-15

Controlling cellular alignment and elongation has been demonstrated as an important parameter for developing nerve tissue engineering scaffolds. Many approaches have been developed to guide cellular orientation for nerve regeneration such as micropatterning techniques. However, most of materials used for developing micropatterning scaffolds lack of bioactivity and biofunctionability. Here we present a functional conductive micropatterned scaffold based on bioactive conductive biodegradable polyurethane prepared using a micro-molding technique. These conductive micropatterned scaffolds are able to not only induce the Schwann cells (SCs) alignment and elongation by the micropatterned surface but also enhance the nerve growth factor (NGF) gene expression of SCs by the bioactivity of these materials. Additionally, the combined effect of the bioactivity of such conductive materials and the micropatterned structure also dramatically promotes the neurite extension and elongation of PC12 cells in a highly aligned direction. These data suggest that these conductive micropatterned scaffolds that easily control cellular orientation and organization, and dramatically enhance NGF gene expression and significantly induce the neurite extension of PC12 cells, have a great potential for nerve regeneration applications. Copyright © 2018 Elsevier Inc. All rights reserved.

Platinum and Palladium Overlayers Dramatically Enhance the Activity of Ruthenium Nanotubes for Alkaline Hydrogen Oxidation

DOE PAGES

St. John, Samuel; Atkinson, Robert W.; Unocic, Kinga A.; ...

2015-10-18

Templated vapor synthesis and thermal annealing were used to synthesize unsupported metallic Ru nanotubes with Pt or Pd overlayers. By controlling the elemental composition and thickness of these overlayers, we obtain nanostructures with very high alkaline hydrogen oxidation activity. For nanotubes with a nominal atomic composition of Ru 0.90Pt 0.10 display a surface-specific activity (2.4 mA/cm 2) that is 35 times greater than that of pure Ru nanotubes at a 50 mV overpotential and 2.5 times greater than that of pure Pt nanotubes (0.98 mA/cm 2). The surface-segregated structure also confers dramatically increased Pt utilization efficiency. We find a platinum-mass-specificmore » activity of 1240 A/gPt for the optimized nanotube versus 280 A/gPt for carbon-supported Pt nanoparticles and 109 A/gPt for monometallic Pt nanotubes. Here, we attribute the enhancement of both area- and platinum-mass-specific activity to the atomic-scale homeomorphism of the nanotube form factor with adlayer-modified polycrystals. Subsurface ligand and bifunctional effects previously observed on segregated, adlayer-modified polycrystals are translated to nanoscale catalysts.« less

Hybrid boron nitride-natural fiber composites for enhanced thermal conductivity.

PubMed

Xia, Changlei; Garcia, Andres C; Shi, Sheldon Q; Qiu, Ying; Warner, Nathaniel; Wu, Yingji; Cai, Liping; Rizvi, Hussain R; D'Souza, Nandika A; Nie, Xu

2016-10-05

Thermal conductivity was dramatically increased after adding natural fiber into hexagonal boron nitride (hBN)/epoxy composites. Although natural fiber does not show high-thermal conductivity itself, this study found that the synergy of natural fiber with hBN could significantly improve thermal conductivity, compared with that solely using hBN. A design of mixtures approach using constant fibers with increasing volume fractions of hBN was examined and compared. The thermal conductivity of the composite containing 43.6% hBN, 26.3% kenaf fiber and 30.1% epoxy reached 6.418 W m -1 K -1 , which was 72.3% higher than that (3.600 W m -1 K -1 ) of the 69.0% hBN and 31.0% epoxy composite. Using the scanning electron microscope (SEM) and micro computed tomography (micro-CT), it was observed that the hBN powders were well distributed and ordered on the fiber surfaces enhancing the ceramic filler's interconnection, which may be the reason for the increase in thermal conductivity. Additionally, the results from mechanical and dynamic mechanical tests showed that performances dramatically improved after adding kenaf fibers into the hBN/epoxy composite, potentially benefiting the composite's use as an engineered material.

Hybrid boron nitride-natural fiber composites for enhanced thermal conductivity

NASA Astrophysics Data System (ADS)

Xia, Changlei; Garcia, Andres C.; Shi, Sheldon Q.; Qiu, Ying; Warner, Nathaniel; Wu, Yingji; Cai, Liping; Rizvi, Hussain R.; D'Souza, Nandika A.; Nie, Xu

2016-10-01

Thermal conductivity was dramatically increased after adding natural fiber into hexagonal boron nitride (hBN)/epoxy composites. Although natural fiber does not show high-thermal conductivity itself, this study found that the synergy of natural fiber with hBN could significantly improve thermal conductivity, compared with that solely using hBN. A design of mixtures approach using constant fibers with increasing volume fractions of hBN was examined and compared. The thermal conductivity of the composite containing 43.6% hBN, 26.3% kenaf fiber and 30.1% epoxy reached 6.418 W m-1 K-1, which was 72.3% higher than that (3.600 W m-1 K-1) of the 69.0% hBN and 31.0% epoxy composite. Using the scanning electron microscope (SEM) and micro computed tomography (micro-CT), it was observed that the hBN powders were well distributed and ordered on the fiber surfaces enhancing the ceramic filler’s interconnection, which may be the reason for the increase in thermal conductivity. Additionally, the results from mechanical and dynamic mechanical tests showed that performances dramatically improved after adding kenaf fibers into the hBN/epoxy composite, potentially benefiting the composite’s use as an engineered material.

Redirecting intracellular trafficking and the secretion pattern of FSH dramatically enhances ovarian function in mice.

PubMed

Wang, Huizhen; Larson, Melissa; Jablonka-Shariff, Albina; Pearl, Christopher A; Miller, William L; Conn, P Michael; Boime, Irving; Kumar, T Rajendra

2014-04-15

FSH and luteinizing hormone (LH) are secreted constitutively or in pulses, respectively, from pituitary gonadotropes in many vertebrates, and regulate ovarian function. The molecular basis for this evolutionarily conserved gonadotropin-specific secretion pattern is not understood. Here, we show that the carboxyterminal heptapeptide in LH is a gonadotropin-sorting determinant in vivo that directs pulsatile secretion. FSH containing this heptapeptide enters the regulated pathway in gonadotropes of transgenic mice, and is released in response to gonadotropin-releasing hormone, similar to LH. FSH released from the LH secretory pathway rescued ovarian defects in Fshb-null mice as efficiently as constitutively secreted FSH. Interestingly, the rerouted FSH enhanced ovarian follicle survival, caused a dramatic increase in number of ovulations, and prolonged female reproductive lifespan. Furthermore, the rerouted FSH vastly improved the in vivo fertilization competency of eggs, their subsequent development in vitro and when transplanted, the ability to produce offspring. Our study demonstrates the feasibility to fine-tune the target tissue responses by modifying the intracellular trafficking and secretory fate of a pituitary trophic hormone. The approach to interconvert the secretory fate of proteins in vivo has pathophysiological significance, and could explain the etiology of several hormone hyperstimulation and resistance syndromes.

Hubble's Slice of Sagittarius

NASA Image and Video Library

2017-12-08

This stunning image, captured by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys (ACS), shows part of the sky in the constellation of Sagittarius (The Archer). The region is rendered in exquisite detail — deep red and bright blue stars are scattered across the frame, set against a background of thousands of more distant stars and galaxies. Two features are particularly striking: the colors of the stars, and the dramatic crosses that burst from the centers of the brightest bodies. While some of the colors in this frame have been enhanced and tweaked during the process of creating the image from the observational data, different stars do indeed glow in different colors. Stars differ in color according to their surface temperature: very hot stars are blue or white, while cooler stars are redder. They may be cooler because they are smaller, or because they are very old and have entered the red giant phase, when an old star expands and cools dramatically as its core collapses. The crosses are nothing to do with the stars themselves, and, because Hubble orbits above Earth’s atmosphere, nor are they due to any kind of atmospheric disturbance. They are actually known as diffraction spikes, and are caused by the structure of the telescope itself. Like all big modern telescopes, Hubble uses mirrors to capture light and form images. Its secondary mirror is supported by struts, called telescope spiders, arranged in a cross formation, and they diffract the incoming light. Diffraction is the slight bending of light as it passes near the edge of an object. Every cross in this image is due to a single set of struts within Hubble itself! Whilst the spikes are technically an inaccuracy, many astrophotographers choose to emphasize and celebrate them as a beautiful feature of their images. Image credit: ESA/Hubble & NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Intravenous immunoglobulin therapy leading to dramatic improvement in a patient with systemic juvenile idiopathic arthritis and severe pericarditis resistant to steroid pulse therapy.

PubMed

Aizawa-Yashiro, Tomomi; Oki, Eishin; Tsuruga, Kazushi; Nakahata, Tohru; Ito, Etsuro; Tanaka, Hiroshi

2012-05-01

A 7-year-old Japanese boy with a 4-month history of systemic juvenile idiopathic arthritis (s-JIA) experienced disease flare with spiking fever, exanthema and arthralgia. He then developed progressive dyspnea due to severe pericarditis, and proinflammatory hypercytokinemia was suspected. Methylprednisolone pulse therapy was ineffective and echocardiography showed massive pericardial effusion had persisted. Alternatively, subsequent intravenous immunoglobulin (IVIG) therapy resulted in dramatic resolution of the pericardial effusion, and his general condition significantly improved within a few days. This case report may lend further support the use of IVIG for selected patients with s-JIA and severe pericarditis.

Giant Enhancement in Radiative Heat Transfer in Sub-30 nm Gaps of Plane Parallel Surfaces.

PubMed

Fiorino, Anthony; Thompson, Dakotah; Zhu, Linxiao; Song, Bai; Reddy, Pramod; Meyhofer, Edgar

2018-06-13

Radiative heat transfer rates that exceed the blackbody limit by several orders of magnitude are expected when the gap size between plane parallel surfaces is reduced to the nanoscale. To date, experiments have only realized enhancements of ∼100 fold as the smallest gap sizes in radiative heat transfer studies have been limited to ∼50 nm by device curvature and particle contamination. Here, we report a 1,200-fold enhancement with respect to the far-field value in the radiative heat flux between parallel planar silica surfaces separated by gaps as small as ∼25 nm. Achieving such small gap sizes and the resultant dramatic enhancement in near-field energy flux is critical to achieve a number of novel near-field based nanoscale energy conversion systems that have been theoretically predicted but remain experimentally unverified.

Enhanced photon-phonon cross-Kerr nonlinearity with two-photon driving.

PubMed

Yin, Tai-Shuang; Lü, Xin-You; Wan, Liang-Liang; Bin, Shang-Wu; Wu, Ying

2018-05-01

We propose a scheme to significantly enhance the cross-Kerr (CK) nonlinearity between photons and phonons in a quadratically coupled optomechanical system (OMS) with two-photon driving. This CK nonlinear enhancement originates from the parametric-driving-induced squeezing and the underlying nonlinear optomechanical interaction. Moreover, the noise of the squeezed mode can be suppressed completely by introducing a squeezed vacuum reservoir. As a result of this dramatic nonlinear enhancement and the suppressed noise, we demonstrate the feasibility of the quantum nondemolition measurement of the phonon number in an originally weak coupled OMS. In addition, the photon-phonon blockade phenomenon is also investigated in this regime, which allows for performing manipulations between photons and phonons. This Letter offers a promising route towards the potential application for the OMS in quantum information processing and quantum networks.

Yonsei Evolutionary Population Synthesis (YEPS). II. Spectro-photometric Evolution of Helium-enhanced Stellar Populations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, Chul; Yoon, Suk-Jin; Lee, Young-Wook, E-mail: chulchung@yonsei.ac.kr, E-mail: sjyoon0691@yonsei.ac.kr

The discovery of multiple stellar populations in Milky Way globular clusters (GCs) has stimulated various follow-up studies on helium-enhanced stellar populations. Here we present the evolutionary population synthesis models for the spectro-photometric evolution of simple stellar populations (SSPs) with varying initial helium abundance ( Y {sub ini}). We show that Y {sub ini} brings about dramatic changes in spectro-photometric properties of SSPs. Like the normal-helium SSPs, the integrated spectro-photometric evolution of helium-enhanced SSPs is also dependent on metallicity and age for a given Y {sub ini}. We discuss the implications and prospects for the helium-enhanced populations in relation to themore » second-generation populations found in the Milky Way GCs. All of the models are available at http://web.yonsei.ac.kr/cosmic/data/YEPS.htm.« less

Toward evaluating the effect of climate change on investments in the water resources sector: insights from the forecast and analysis of hydrological indicators in developing countries

NASA Astrophysics Data System (ADS)

Strzepek, Kenneth; Jacobsen, Michael; Boehlert, Brent; Neumann, James

2013-12-01

The World Bank has recently developed a method to evaluate the effects of climate change on six hydrological indicators across 8951 basins of the world. The indicators are designed for decision-makers and stakeholders to consider climate risk when planning water resources and related infrastructure investments. Analysis of these hydrological indicators shows that, on average, mean annual runoff will decline in southern Europe; most of Africa; and in southern North America and most of Central and South America. Mean reference crop water deficit, on the other hand, combines temperature and precipitation and is anticipated to increase in nearly all locations globally due to rising global temperatures, with the most dramatic increases projected to occur in southern Europe, southeastern Asia, and parts of South America. These results suggest overall guidance on which regions to focus water infrastructure solutions that could address future runoff flow uncertainty. Most important, we find that uncertainty in projections of mean annual runoff and high runoff events is higher in poorer countries, and increases over time. Uncertainty increases over time for all income categories, but basins in the lower and lower-middle income categories are forecast to experience dramatically higher increases in uncertainty relative to those in the upper-middle and upper income categories. The enhanced understanding of the uncertainty of climate projections for the water sector that this work provides strongly support the adoption of rigorous approaches to infrastructure design under uncertainty, as well as design that incorporates a high degree of flexibility, in response to both risk of damage and opportunity to exploit water supply ‘windfalls’ that might result, but would require smart infrastructure investments to manage to the greatest benefit.

OGLE-2017-BLG-0329L: A Microlensing Binary Characterized with Dramatically Enhanced Precision Using Data from Space-based Observations

NASA Astrophysics Data System (ADS)

Han, C.; Calchi Novati, S.; Udalski, A.; Lee, C.-U.; Gould, A.; Bozza, V.; Mróz, P.; Pietrukowicz, P.; Skowron, J.; Szymański, M. K.; Poleski, R.; Soszyński, I.; Kozłowski, S.; Ulaczyk, K.; Pawlak, M.; Rybicki, K.; Iwanek, P.; The OGLE Collaboration; Albrow, M. D.; Chung, S.-J.; Hwang, K.-H.; Jung, Y. K.; Ryu, Y.-H.; Shin, I.-G.; Shvartzvald, Y.; Yee, J. C.; Zang, W.; Zhu, W.; Cha, S.-M.; Kim, D.-J.; Kim, H.-W.; Kim, S.-L.; Lee, D.-J.; Lee, Y.; Park, B.-G.; Pogge, R. W.; Kim, W.-T.; The KMTNet Collaboration; Beichman, C.; Bryden, G.; Carey, S.; Gaudi, B. S.; Henderson, C. B.; The Spitzer Team; Dominik, M.; Helling, C.; Hundertmark, M.; Jørgensen, U. G.; Longa-Peña, P.; Lowry, S.; Sajadian, S.; Burgdorf, M. J.; Campbell-White, J.; Ciceri, S.; Evans, D. F.; Haikala, L. K.; Hinse, T. C.; Rahvar, S.; Rabus, M.; Snodgrass, C.; The MiNDSTEp Collaboration

2018-06-01

Mass measurements of gravitational microlenses require one to determine the microlens parallax π E, but precise π E measurement, in many cases, is hampered due to the subtlety of the microlens-parallax signal combined with the difficulty of distinguishing the signal from those induced by other higher-order effects. In this work, we present the analysis of the binary-lens event OGLE-2017-BLG-0329, for which π E is measured with a dramatically improved precision using additional data from space-based Spitzer observations. We find that while the parallax model based on the ground-based data cannot be distinguished from a zero-π E model at the 2σ level, the addition of the Spitzer data enables us to identify two classes of solutions, each composed of a pair of solutions according to the well-known ecliptic degeneracy. It is found that the space-based data reduce the measurement uncertainties of the north and east components of the microlens-parallax vector {{\\boldsymbol{π }}}{{E}} by factors ∼18 and ∼4, respectively. With the measured microlens parallax combined with the angular Einstein radius measured from the resolved caustic crossings, we find that the lens is composed of a binary with component masses of either (M 1, M 2) ∼ (1.1, 0.8) M ⊙ or ∼(0.4, 0.3) M ⊙ according to the two solution classes. The first solution is significantly favored but the second cannot be securely ruled out based on the microlensing data alone. However, the degeneracy can be resolved from adaptive optics observations taken ∼10 years after the event.

Ti-Sb-Te alloy: a candidate for fast and long-life phase-change memory.

PubMed

Xia, Mengjiao; Zhu, Min; Wang, Yuchan; Song, Zhitang; Rao, Feng; Wu, Liangcai; Cheng, Yan; Song, Sannian

2015-04-15

Phase-change memory (PCM) has great potential for numerous attractive applications on the premise of its high-device performances, which still need to be improved by employing a material with good overall phase-change properties. In respect to fast speed and high endurance, the Ti-Sb-Te alloy seems to be a promising candidate. Here, Ti-doped Sb2Te3 (TST) materials with different Ti concentrations have been systematically studied with the goal of finding the most suitable composition for PCM applications. The thermal stability of TST is improved dramatically with increasing Ti content. The small density change of T0.32Sb2Te3 (2.24%), further reduced to 1.37% for T0.56Sb2Te3, would greatly avoid the voids generated at phase-change layer/electrode interface in a PCM device. Meanwhile, the exponentially diminished grain size (from ∼200 nm to ∼12 nm), resulting from doping more and more Ti, enhances the adhesion between phase-change film and substrate. Tests of TST-based PCM cells have demonstrated a fast switching rate of ∼10 ns. Furthermore, because of the lower thermal conductivities of TST materials, compared with Sb2Te3-based PCM cells, T0.32Sb2Te3-based ones exhibit lower required pulse voltages for Reset operation, which largely decreases by ∼50% for T0.43Sb2Te3-based ones. Nevertheless, the operation voltages for T0.56Sb2Te3-based cells dramatically increase, which may be due to the phase separation after doping excessive Ti. Finally, considering the decreased resistance ratio, TixSb2Te3 alloy with x around 0.43 is proved to be a highly promising candidate for fast and long-life PCM applications.

Protective Effect of Lactobacillus casei Strain Shirota on Shiga Toxin-Producing Escherichia coli O157:H7 Infection in Infant Rabbits

PubMed Central

Ogawa, Michinaga; Shimizu, Kensuke; Nomoto, Koji; Takahashi, Masatoshi; Watanuki, Masaaki; Tanaka, Ryuichiro; Tanaka, Tetsuya; Hamabata, Takashi; Yamasaki, Shinji; Takeda, Yoshifumi

2001-01-01

We examined colonization patterns of Shiga toxin-producing Escherichia coli (STEC), concentrations of Shiga toxins (Stxs) and specific immunoglobulin A (lgA) against Stxs and STEC bacterial cell surface antigen in various portions of the gastrointestinal tract in an infant rabbit infection model. After inoculation of 3-day-old infant rabbits with STEC strain 89020087 at low doses (∼103 CFU/body), numbers of colonizing STEC bacteria and concentrations of Stxs in the intestine increased dramatically and the animals developed diarrhea within a couple of days after infection. Daily administration of Lactobacillus casei from the day of birth dramatically decreased the severity of diarrhea and lowered STEC colonization levels in the gastrointestinal tract 100-fold day 7 after infection. Both Stx1 and Stx2 concentrations in the intestines and histological damage to the intestinal mucus induced by STEC infection were decreased by the administration of L. casei. Examination of the concentrations of volatile fatty acids and pH of the intestinal contents revealed that the protective effect of L. casei administration against STEC infection was not due to fermented products such as lactic acid in the gastrointestinal tract. Administration of L. casei increased levels of lgAs against Stx1, Stx2, and formalin-killed STEC cells in the colon approximately two-, four-, and threefold, respectively, compared with those of the untreated controls by day 7 after infection. These results suggest that administration of L. casei strain Shirota enhances the local immune responses to STEC cells and Stxs and leads to elimination of STEC and thus decreases Stx concentrations in the intestines. PMID:11160007

Leveraging data to systematically improve care: coronary artery disease management at Geisinger.

PubMed

Graf, Thomas; Erskine, Alistair; Steele, Glenn D

2014-01-01

Coronary artery disease is complex chronic disease best managed by a team empowered by actionable data and a comprehensive approach, the ability to improve intermediate outcomes was dramatically enhanced after Geisinger created a system of care to do so. Continuous measurement of critical data elements of process and intermediate outcome measures allows the delivery of actionable information to the most appropriate team member, including the patients and family as team members. Continuous monitoring of the overall program looking for trends and opportunities across sites and regions allows for program enhancements. The comprehensive "all-or-none" bundled approach to care, which has already realized a 300% improvement, will be further enhanced by incorporating additional "Big Data" flows.

Transgenic plants with enhanced growth characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of themore » double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.« less

Proximity-driven enhanced magnetic order at ferromagnetic-insulator-magnetic-topological-insulator interface

DOE PAGES

Li, Mingda; Zhu, Yimei; Chang, Cui -Zu; ...

2015-08-17

Magnetic exchange driven proximity effect at a magnetic-insulator–topological-insulator (MI-TI) interface provides a rich playground for novel phenomena as well as a way to realize low energy dissipation quantum devices. In this study, we report a dramatic enhancement of proximity exchange coupling in the MI/magnetic-TI EuS/Sb 2–xV xTe 3 hybrid heterostructure, where V doping is used to drive the TI (Sb 2Te 3) magnetic. We observe an artificial antiferromagneticlike structure near the MI-TI interface, which may account for the enhanced proximity coupling. The interplay between the proximity effect and doping in a hybrid heterostructure provides insights into the engineering of magneticmore » ordering.« less

The Misfortunes of Moral Enhancement.

PubMed

Azevedo, Marco Antonio

2016-10-01

In Unfit for the Future, Ingmar Persson and Julian Savulescu present a sophisticated argument in defense of the imperative of moral enhancement. They claim that without moral enhancement, the future of humanity is seriously compromised. The possibility of ultimate harm, caused by a dreadful terrorist attack or by a final unpreventable escalation of the present environmental crisis aggravated by the availability of cognitive enhancement, makes moral enhancement a top priority. It may be considered optimistic to think that our present moral capabilities can be successfully improved by means of moral education, moral persuasion, and fear of punishment. So, without moral enhancement, drastic restrictions on human freedom would become the only alternative to prevent those dramatic potential outcomes. In this article, I will try to show that we still have reason to be less pessimistic and that Persson & Savulescu's arguments are fortunately unconvincing. © The Author 2016. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Direct imaging and spectroscopy of terrestrial planets with JWST and a starsahde

NASA Astrophysics Data System (ADS)

Soummer, R.; Valenti, J.; Brown, R. A.; Seager, S.; Tumlinson, J.; Cash, W.; Jordan, I.; Postman, M.; Mountain, M.; Glassman, T.; Pueyo, L.; Roberge, A.; NWP Team

2010-10-01

We present a study for using a starshade with the James Webb Space Telescope (JWST). This concept would enable imaging and spectroscopy of a planet similar to the Earth, the study of its habitability, and the search for signs of alien life. JWST was not specifically designed to observe with a starshade, but its instrumentation and its great sensitivity make it capable of achieving major results in the study of terrestrial-mass exoplanets. However, there are some challenges for the starshade designs mainly due to the very large wavelength sensitivity of the HgCdTe detectors. We discuss the combination of a starshade with internal filters in NIRCam and NIRSpec to optimize both science return and starshade performance. We discuss a possible filter upgrade to enable feasible observations of Earth-like planets and in particular spectroscopic characterization in the near infrared. The new filter would not affect NIRSpec's scientific performance nor its operations, but it would dramatically reduce the risk of adding a starshade to JWST in the future and enhance the performance of any starshade that is built.

Assessing hazards along our Nation's coasts

USGS Publications Warehouse

Hapke, Cheryl J.; Brenner, Owen; Henderson, Rachel E.; Reynolds, B.J.

2013-01-01

Coastal areas are essential to the economic, cultural, and environmental health of the Nation, yet by nature coastal areas are constantly changing due to a variety of events and processes. Extreme storms can cause dramatic changes to our shorelines in a matter of hours, while sea-level rise can profoundly alter coastal environments over decades. These changes can have a devastating impact on coastal communities, such as the loss of homes built on retreating sea cliffs or protective dunes eroded by storm waves. Sometimes, however, the changes can be positive, such as new habitat created by storm deposits. The U.S. Geological Survey (USGS) is meeting the need for scientific understanding of how our coasts respond to different hazards with continued assessments of current and future changes along U.S. coastlines. Through the National Assessment of Coastal Change Hazards (NACCH), the USGS carries out the unique task of quantifying coastal change hazards along open-ocean coasts in the United States and its territories. Residents of coastal communities, emergency managers, and other stakeholders can use science-based data, tools, models, and other products to improve planning and enhance resilience.

Research on intercultural effectiveness and its relevance to multicultural crews in space.

PubMed

Kealey, Daniel J

2004-07-01

The planning for and managing of missions in space is changing dramatically due to, among other things, the involvement of more and more national cultures. In light of the need to better understand the influence and management of cultural differences among the crewmembers who will live and work in space in the future, the aim of this paper is threefold. First, some of the key research findings on intercultural effectiveness on Earth are presented and their relevance to the functioning of multicultural crews in space is discussed. Second, issues that will need to be addressed in order to maximize the effective functioning of multicultural teams in space are identified. These include improving the procedures for the screening and selection, intercultural training, monitoring and support, and debriefing and re-entry of astronauts and their families. Finally, the paper concludes with the presentation and discussion of some of the key activities that will need to be undertaken to address these issues and, thereby, enhance the overall functioning of multicultural teams living and working in space.

Decreased bone formation and increased osteoclastogenesis cause bone loss in mucolipidosis II

PubMed Central

Kollmann, Katrin; Pestka, Jan Malte; Kühn, Sonja Christin; Schöne, Elisabeth; Schweizer, Michaela; Karkmann, Kathrin; Otomo, Takanobu; Catala-Lehnen, Philip; Failla, Antonio Virgilio; Marshall, Robert Percy; Krause, Matthias; Santer, Rene; Amling, Michael; Braulke, Thomas; Schinke, Thorsten

2013-01-01

Mucolipidosis type II (MLII) is a severe multi-systemic genetic disorder caused by missorting of lysosomal proteins and the subsequent lysosomal storage of undegraded macromolecules. Although affected children develop disabling skeletal abnormalities, their pathogenesis is not understood. Here we report that MLII knock-in mice, recapitulating the human storage disease, are runted with accompanying growth plate widening, low trabecular bone mass and cortical porosity. Intralysosomal deficiency of numerous acid hydrolases results in accumulation of storage material in chondrocytes and osteoblasts, and impaired bone formation. In osteoclasts, no morphological or functional abnormalities are detected whereas osteoclastogenesis is dramatically increased in MLII mice. The high number of osteoclasts in MLII is associated with enhanced osteoblastic expression of the pro-osteoclastogenic cytokine interleukin-6, and pharmacological inhibition of bone resorption prevented the osteoporotic phenotype of MLII mice. Our findings show that progressive bone loss in MLII is due to the presence of dysfunctional osteoblasts combined with excessive osteoclastogenesis. They further underscore the importance of a deep skeletal phenotyping approach for other lysosomal diseases in which bone loss is a prominent feature. PMID:24127423

Reactive Oxygen Species-Mediated Cellular Stress Response and Lipid Accumulation in Oleaginous Microorganisms: The State of the Art and Future Perspectives

PubMed Central

Shi, Kun; Gao, Zhen; Shi, Tian-Qiong; Song, Ping; Ren, Lu-Jing; Huang, He; Ji, Xiao-Jun

2017-01-01

Microbial oils, which are mainly extracted from yeasts, molds, and algae, have been of considerable interest as food additives and biofuel resources due to their high lipid content. While these oleaginous microorganisms generally produce only small amounts of lipids under optimal growth conditions, their lipid accumulation machinery can be induced by environmental stresses, such as nutrient limitation and an inhospitable physical environmental. As common second messengers of many stress factors, reactive oxygen species (ROS) may act as a regulator of cellular responses to extracellular environmental signaling. Furthermore, increasing evidence indicates that ROS may act as a mediator of lipid accumulation, which is associated with dramatic changes in the transcriptome, proteome, and metabolome. However, the specific mechanisms of ROS involvement in the crosstalk between extracellular stress signaling and intracellular lipid synthesis require further investigation. Here, we summarize current knowledge on stress-induced lipid biosynthesis and the putative role of ROS in the control of lipid accumulation in oleaginous microorganisms. Understanding such links may provide guidance for the development of stress-based strategies to enhance microbial lipid production. PMID:28507542

Effects of local structure of Ce3+ ions on luminescent properties of Y3Al5O12:Ce nanoparticles

PubMed Central

He, Xiaowu; Liu, Xiaofang; Li, Rongfeng; Yang, Bai; Yu, Kaili; Zeng, Min; Yu, Ronghai

2016-01-01

Ce3+-doped yttrium aluminum garnet (YAG:Ce) nanocrystals were successfully synthesized via a facile sol-gel method. Multiple characterization techniques were employed to study the structure, morphology, composition and photoluminescence properties of YAG:Ce nanophosphors. The YAG:Ce0.0055 sintered at 1030 °C exhibited a typical 5d1-4f1 emission band with the maximum peak located at 525 nm, and owned a short fluorescence lifetime τ1 (~28 ns) and a long fluorescence lifetime τ2 (~94 ns). Calcination temperature and Ce3+ doping concentration have significant effects on the photoluminescence properties of the YAG:Ce nanophosphors. The emission intensity was enhanced as the calcination temperature increased from 830 to 1030 °C, but decreased dramatically with the increase of Ce3+ doping concentration from 0.55 to 5.50 at.% due to the concentration quenching. By optimizing the synthesized condition, the strongest photoluminescence emission intensity was achieved at 1030 °C with Ce3+ concentration of 0.55 at.%. PMID:26935980

EFFECT OF MECHANICAL STIMULI ON SKELETAL REGENERATION AROUND IMPLANTS

PubMed Central

Leucht, Philipp; Kim, Jae-Beom; Wazen, Rima; Currey, Jennifer A.; Nanci, Antonio; Brunski, John B.; Helms, Jill A.

2007-01-01

Due to the aging population and the increasing need for total joint replacements, osseointegration is of a great interest for various clinical disciplines. Our objective was to investigate the molecular and cellular foundation that underlies this process. Here, we used an in vivo mouse model to study the cellular and molecular response in three distinct areas of unloaded implants: the periosteum, the gap between implant and cortical bone, and the marrow space. Our analyses began with the early phases of healing, and continued until the implants were completely osseointegrated. We investigated aspects of osseointegration ranging from vascularization, cell proliferation, differentiation, and bone remodeling. In doing so, we gained an understanding of the healing mechanisms of different skeletal tissues during unloaded implant osseointegration. To continue our analysis, we used a micromotion device to apply a defined physical stimulus to the implants, and in doing so, we dramatically enhanced bone formation in the peri-implant tissue. By comparing strain measurements with cellular and molecular analyses, we developed an understanding of the correlation between strain magnitudes and fate decisions of cells shaping the skeletal regenerate. PMID:17175211

Measles Elimination Activities in the Western Pacific Region: Experience from the Republic of Korea

PubMed Central

Choe, Young June; Jee, Youngmee; Oh, Myoung-don

2015-01-01

We describe the global status of measles control and elimination, including surveillance and vaccination coverage data provided by the World Health Organization (WHO). Since 2000, two doses of measles vaccine (MCV2) became recommended globally and the achievement of high vaccination coverage has led to dramatic decrease in the measles incidence. Our finding indicates that, in the Western Pacific Region (WPR), substantial progress has been made to control measles transmission in some countries; however, the measles virus continues to circulate, causing outbreaks. The Republic of Korea (ROK) experienced a series of resurgence of measles due to the importation and healthcare-associated transmission in infants, however overall incidence and surveillance indicators met the WHO criteria for measles elimination. The ROK was verified to be measles-free along with Australia, Mongolia, and Macau, China in 2014. One of the effective elimination activities was the establishment of solid keep-up vaccination system in school settings. The lessons learnt from the measles elimination activities in Korea may contribute to enhancing the surveillance schemes and strengthening of vaccination programs in member countries and areas of WPR. PMID:26617443

Altered UV absorbance and cytotoxicity of chlorinated sunscreen agents.

PubMed

Sherwood, Vaughn F; Kennedy, Steven; Zhang, Hualin; Purser, Gordon H; Sheaff, Robert J

2012-12-01

Sunscreens are widely utilized due to the adverse effects of ultraviolet (UV) radiation on human health. The safety of their active ingredients as well as that of any modified versions generated during use is thus of concern. Chlorine is used as a chemical disinfectant in swimming pools. Its reactivity suggests sunscreen components might be chlorinated, altering their absorptive and/or cytotoxic properties. To test this hypothesis, the UV-filters oxybenzone, dioxybenzone, and sulisobenzone were reacted with chlorinating agents and their UV spectra analyzed. In all cases, a decrease in UV absorbance was observed. Given that chlorinated compounds can be cytotoxic, the effect of modified UV-filters on cell viability was examined. Chlorinated oxybenzone and dioxybenzone caused significantly more cell death than unchlorinated controls. In contrast, chlorination of sulisobenzone actually reduced cytotoxicity of the parent compound. Exposing a commercially available sunscreen product to chlorine also resulted in decreased UV absorbance, loss of UV protection, and enhanced cytotoxicity. These observations show chlorination of sunscreen active ingredients can dramatically decrease UV absorption and generate derivatives with altered biological properties.

A water-processable organic electron-selective layer for solution-processed inverted organic solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Dongcheng; Zhou, Hu; Cai, Ping

2014-02-03

A triazine- and pyridinium-containing water-soluble material of 1,1′,1″-(4,4′,4″-(1,3,5-triazine-2,4,6-triyl)tris(benzene-4,1-diyl)) tris(methylene)tripyridinium bromide (TzPyBr) was developed as an organic electron-selective layer in solution-processed inverted organic solar cells due to its strong anti-erosion capacity against non-polar organic solvents commonly used for the active layer. Ohmic-like contact with the adjacent active materials like fullerene derivatives is speculated to be formed, as confirmed by the work-function measurements with scanning Kelvin probe and ultraviolet photoelectron spectroscopy techniques. Besides, considering the deep highest occupied molecular orbital energy level of TzPyBr, excellent hole-blocking property of the electron-selective layer is also anticipated. The inverted organic photovoltaic devices based on themore » TzPyBr/ITO (indium tin oxide) bilayer cathode exhibit dramatically enhanced performance compared to the control devices with bare ITO as the cathode and even higher efficiency than the conventional type devices with ITO and Al as the electrodes.« less

Measles Elimination Activities in the Western Pacific Region: Experience from the Republic of Korea.

PubMed

Choe, Young June; Jee, Youngmee; Oh, Myoung-don; Lee, Jong-Koo

2015-11-01

We describe the global status of measles control and elimination, including surveillance and vaccination coverage data provided by the World Health Organization (WHO). Since 2000, two doses of measles vaccine (MCV2) became recommended globally and the achievement of high vaccination coverage has led to dramatic decrease in the measles incidence. Our finding indicates that, in the Western Pacific Region (WPR), substantial progress has been made to control measles transmission in some countries; however, the measles virus continues to circulate, causing outbreaks. The Republic of Korea (ROK) experienced a series of resurgence of measles due to the importation and healthcare-associated transmission in infants, however overall incidence and surveillance indicators met the WHO criteria for measles elimination. The ROK was verified to be measles-free along with Australia, Mongolia, and Macau, China in 2014. One of the effective elimination activities was the establishment of solid keep-up vaccination system in school settings. The lessons learnt from the measles elimination activities in Korea may contribute to enhancing the surveillance schemes and strengthening of vaccination programs in member countries and areas of WPR.

Regional 3-D Modeling of Ground Geoelectric Field for the Northeast United States due to Realistic Geomagnetic Disturbances

NASA Astrophysics Data System (ADS)

Ivannikova, E.; Kruglyakov, M.; Kuvshinov, A. V.; Rastaetter, L.; Pulkkinen, A. A.; Ngwira, C. M.

2017-12-01

During extreme space weather events electric currents in the Earth's magnetosphere and ionosphere experience large variations, which leads to dramatic intensification of the fluctuating magnetic field at the surface of the Earth. According to Faraday's law of induction, the fluctuating geomagnetic field in turn induces electric field that generates harmful currents (so-called "geomagnetically induced currents"; GICs) in grounded technological systems. Understanding (via modeling) of the spatio-temporal evolution of the geoelectric field during enhanced geomagnetic activity is a key consideration in estimating the hazard to technological systems from space weather. We present the results of ground geoelectric field modeling for the Northeast United States, which is performed with the use of our novel numerical tool based on integral equation approach. The tool exploits realistic regional three-dimensional (3-D) models of the Earth's electrical conductivity and realistic global models of the spatio-temporal evolution of the magnetospheric and ionospheric current systems responsible for geomagnetic disturbances. We also explore in detail the manifestation of the coastal effect (anomalous intensification of the geoelectric field near the coasts) in this region.

D-Glucosamine Conjugation Accelerates the Labeling Efficiency of Quantum Dots in Osteoblastic Cells

PubMed Central

Xie, Ming-Fang

2014-01-01

Quantum dots (QDs) are useful imaging tools in the medical and biological fields due to their optical properties, such as a high fluorescence intensity, remarkable resistance to photobleaching, broad absorption spectra, and narrow emission spectra. This is the first study to investigate the uptake of carboxylated QDs conjugated with D-glucosamine (core size: approximately 3 nm, final modified size: 20–30 nm) into cultured osteoblastic cells. The QDs attached to the cell surface and were transported into the cytoplasm within approximately three hours of culture, whose process was clearly demonstrated using specific fluorescent staining of the cell membrane. Although the intranuclear distribution was not observed, a dramatic decrease in the transfer of quantum dots into the cytoplasm was recognized after approximately seven days of culture. Other interesting phenomena include the escape of the quantum dots from lysosomes in the cytoplasm, as confirmed by the merging of both QD fluorescence and specific fluorescent staining of lysosomes in the cytoplasm. These findings suggest that D-glucosamine conjugation enhances proton absorption in acid organelles and promotes the lysosomal escape of QDs. PMID:24818156

Theory of the magnetic skyrmion glass

NASA Astrophysics Data System (ADS)

Hoshino, Shintaro; Nagaosa, Naoto

2018-01-01

Skyrmions and skyrmion crystal (SkX) discovered in chiral magnets show unique physical properties due to their nontrivial topology such as the stability against the annihilation and the motion driven by the ultralow current density, which can be advantageous for the device applications such as magnetic memories. Especially, the chiral dynamics, i.e., the velocity perpendicular to the force acting on a skyrmion, is a key to avoid the impurity potential and enhances its mobility. However, the collective pinning of SkX occurs by the disorder, which is crucial for its low energy properties. Here we study theoretically the low energy dynamics of SkX in the presence of disorder effects in terms of replica field theory, and reveal nonreciprocal collective modes and their electromagnetic responses along the direction of the external magnetic field. The physical quantities such as the relaxation rate of μ SR /NMR and the pinning frequency show a dramatic change associated with the topological phase transition from the helical state to SkX. These results provide a firm basis to explore the glassy state of SkX.

Spinterface between tris(8-hydroxyquinoline)metal(III) molecules and magnetic surfaces: a first-principles study

NASA Astrophysics Data System (ADS)

Jiang, W.; Wang, Jingying; Dougherty, Daniel; Liu, Feng; Feng Liu Team; Daniel Dougherty Team

Using first-principles calculations, we have systematically investigated the hybridization between tris(8-hydroxyquinoline)metal(III) (Mq3, M = Fe, Cr, Al) molecules and magnetic substrates (Co and Cr). Mq3 with different central metal elements but the same organic framework has dramatically different interaction with different magnetic substrates, which affect the interface state significantly. AFM coupling was observed between magnetic Mq3 molecules and ferromagnetic (Co) as well as antiferromagnetic (Cr) substrate, manifested with a superexchange and direct exchange interaction, respectively. Such strong magnetic interfacial coupling may open a gap around the Fermi level and significantly change interface transport properties. Nonmagnetic Alq3 molecule was found to enhance the interface spin polarization due to hybridization between the lowest unoccupied molecular orbitals (LUMO) of Alq3 and metallic surface state. These findings will help better understand spinterface and shed new light on future application of Mq3 molecules in spintronics devices. This work was support by NSF-MRSEC (DMR-1121252) and DOE-BES (DE-FG02-04ER46148).

Probing localized strain in solution-derived YB a2C u3O7 -δ nanocomposite thin films

NASA Astrophysics Data System (ADS)

Guzman, Roger; Gazquez, Jaume; Mundet, Bernat; Coll, Mariona; Obradors, Xavier; Puig, Teresa

2017-07-01

Enhanced pinning due to nanoscale strain is unique to the high-Tc cuprates, where pairing may be modified with lattice distortion. Therefore a comprehensive understanding of the defect landscape is required for a broad range of applications. However, determining the type and distribution of defects and their associated strain constitutes a critical task, and for this aim, real-space techniques for atomic resolution characterization are necessary. Here, we use scanning transmission electron microscopy (STEM) to study the atomic structure of individual defects of solution-derived YB a2C u3O7 (YBCO) nanocomposites, where the inclusion of incoherent secondary phase nanoparticles within the YBCO matrix dramatically increases the density of Y1B a2C u4O8 (Y124) intergrowths, the commonest defect in YBCO thin films. The formation of the Y124 is found to trigger a concatenation of strain-derived interactions with other defects and the concomitant nucleation of intrinsic defects, which weave a web of randomly distributed nanostrained regions that profoundly transform the vortex-pinning landscape of the YBCO nanocomposite thin films.

Pore-scale Modeling of CO2 Local Trapping in Heterogeneous Porous Media with Inter-granular Cements

NASA Astrophysics Data System (ADS)

Wang, D.; Li, Y.

2017-12-01

Based on pore-scale modeling of CO2/brine multiphase flow in heterogeneous porous media with inter-granular cements, we numerically analyze the effects of cement-modified pore structure on CO2 local trapping. Results indicate: 1) small pore throat is the main reason for causing CO2 local trapping in front of low-porosity layers (namely dense layers) formed by inter-granular cements; 2) in the case of the same pore throat size, the smaller particle size can increase the number of flow paths for CO2 plume and equivalently enhances local permeability, which may counteract the impediment of high capillary pressure on CO2 migration to some extent and consequently disables CO2 local capillary trapping; 3) the isolated pores by inter-granular cements can lead to dramatic reduction of CO2 saturation inside the dense layers, whereas the change of connectivity of some pores due to the cements can increase CO2 accumulation in front of the dense layers by lowering the displacement area of CO2 plume.

Long-term affects of experimental flows on riverine biota below a reservoir

NASA Astrophysics Data System (ADS)

Robinson, Chris; Ortlepp, Johannes

2010-05-01

Large dams have altered the flow regime of most rivers on the globe with consequent effects on riverine biota. Experimental flows (multiple floods per year) have been used on the regulated Spöl River below Livigno Reservoir for over 9 years to enhance the ecological condition of the river. The flow program has improved the brown trout fishery in the river as indicated by an increased number of redds. Floods have reset periphyton assemblages from a moss-dominated streambed to one dominated by diatoms and patches of filamentous algae. Zoobenthic assemblages have shown dramatic shifts in benthic structure in line with predictions from altered state models. Ecosystem regime shifts have been characterized with increases in parameter variances followed by periods of stable states. The system appears to be entering a second zoobenthic regime shift after year 8, perhaps in response to biotic interactions due to changes in the fishery. The response patterns clearly show that a long-term perspective must be in place when assessing biotic responses to changes in physical habitat properties resulting from flow experiments.

Simulation of Ultra-Small MOSFETs Using a 2-D Quantum-Corrected Drift-Diffusion Model

NASA Technical Reports Server (NTRS)

Biegel, Bryan A.; Rafferty, Conor S.; Yu, Zhiping; Dutton, Robert W.; Ancona, Mario G.; Saini, Subhash (Technical Monitor)

1998-01-01

We describe an electronic transport model and an implementation approach that respond to the challenges of device modeling for gigascale integration. We use the density-gradient (DG) transport model, which adds tunneling and quantum smoothing of carrier density profiles to the drift-diffusion model. We present the current implementation of the DG model in PROPHET, a partial differential equation solver developed by Lucent Technologies. This implementation approach permits rapid development and enhancement of models, as well as run-time modifications and model switching. We show that even in typical bulk transport devices such as P-N diodes and BJTs, DG quantum effects can significantly modify the I-V characteristics. Quantum effects are shown to be even more significant in small, surface transport devices, such as sub-0.1 micron MOSFETs. In thin-oxide MOS capacitors, we find that quantum effects may reduce gate capacitance by 25% or more. The inclusion of quantum effects in simulations dramatically improves the match between C-V simulations and measurements. Significant quantum corrections also occur in the I-V characteristics of short-channel MOSFETs due to the gate capacitance correction.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, Seung-Min; Oh, Pilgun; Kim, Sang-Ok

A low-cost sodium-ion full cell with a O3-type layered Na[Cu 0.2(Fe 1/3Mn2/3) 0.8]O 2 cathode and an alloy-type P-TiP2-C anode is presented. The cathode is synthesized by an oxalate coprecipitation method and optimized cathodes shows a high specific capacity of 135 mAh g -1 at 0.1C rate with a high rate capability of 90 mAh g-1 at 1C rate and 70 mAh g -1 at 2C rate with good cyclability. The full cell exhibits better capacity retention than the half cell with the cathode due to the elimination of the degradation caused by sodium-metal anode. The dramatically enhanced electrochemical performancemore » of the Na[Cu 0.2(Fe 1/3Mn 2/3) 0.8]O 2 / P-TiP 2-C full cell compared to that of the sample with no Cu is attributed to the structural stabilization imparted by Cu by suppressing the phase change from the O3 structure to the P3 structure during cycling.« less

Simulating chemical reactions in ionic liquids using QM/MM methodology.

PubMed

Acevedo, Orlando

2014-12-18

The use of ionic liquids as a reaction medium for chemical reactions has dramatically increased in recent years due in large part to the numerous reported advances in catalysis and organic synthesis. In some extreme cases, ionic liquids have been shown to induce mechanistic changes relative to conventional solvents. Despite the large interest in the solvents, a clear understanding of the molecular factors behind their chemical impact is largely unknown. This feature article reviews our efforts developing and applying mixed quantum and molecular mechanical (QM/MM) methodology to elucidate the microscopic details of how these solvents operate to enhance rates and alter mechanisms for industrially and academically important reactions, e.g., Diels-Alder, Kemp eliminations, nucleophilic aromatic substitutions, and β-eliminations. Explicit solvent representation provided the medium dependence of the activation barriers and atomic-level characterization of the solute-solvent interactions responsible for the experimentally observed "ionic liquid effects". Technical advances are also discussed, including a linear-scaling pairwise electrostatic interaction alternative to Ewald sums, an efficient polynomial fitting method for modeling proton transfers, and the development of a custom ionic liquid OPLS-AA force field.

Sensitized phosphorescence of benzil-doped ladder-type methyl-poly(para-phenylene)

NASA Astrophysics Data System (ADS)

Bagnich, S. A.; Bässler, H.; Neher, D.

2004-11-01

The delayed luminescence and phosphorescence of ladder-type methyl-poly(para-phenylene) (MeLPPP) doped with benzil at a concentration of 20% by weight has been measured. The introduction of benzil leads to a dramatic reduction of the polymer singlet emission. At the same time, a new band with maximum at 611 nm appears, corresponding to the phosphorescence of MeLPPP. The phosphorescence decay on the short time scale is close to an exponential law with a time decay of 15 ms. This indicates that benzil can efficiently sensitize the phosphorescence of the polymer. In addition, a broad and featureless emission is observed in the delayed luminescence spectra of benzil-doped MeLPPP, which is attributed to an exciplex formed between the polymer host and the dopant. We further observe that the delayed fluorescence is enhanced by the addition of benzil. It is concluded that the delayed fluorescence of benzil-doped MeLPPP is mainly due to the annihilation of triplet excitons on the polymer. Finally, efficient triplet-triplet energy transfer from the benzil-doped polymer to the red-emitting phosphorescent dye Pt(II)octaethylporphyrin is established.

Changes in Arctic vegetation amplify high-latitude warming through the greenhouse effect.

PubMed

Swann, Abigail L; Fung, Inez Y; Levis, Samuel; Bonan, Gordon B; Doney, Scott C

2010-01-26

Arctic climate is projected to change dramatically in the next 100 years and increases in temperature will likely lead to changes in the distribution and makeup of the Arctic biosphere. A largely deciduous ecosystem has been suggested as a possible landscape for future Arctic vegetation and is seen in paleo-records of warm times in the past. Here we use a global climate model with an interactive terrestrial biosphere to investigate the effects of adding deciduous trees on bare ground at high northern latitudes. We find that the top-of-atmosphere radiative imbalance from enhanced transpiration (associated with the expanded forest cover) is up to 1.5 times larger than the forcing due to albedo change from the forest. Furthermore, the greenhouse warming by additional water vapor melts sea-ice and triggers a positive feedback through changes in ocean albedo and evaporation. Land surface albedo change is considered to be the dominant mechanism by which trees directly modify climate at high-latitudes, but our findings suggest an additional mechanism through transpiration of water vapor and feedbacks from the ocean and sea-ice.

Top-Contact Self-Aligned Printing for High-Performance Carbon Nanotube Thin-Film Transistors with Sub-Micron Channel Length.

PubMed

Cao, Xuan; Wu, Fanqi; Lau, Christian; Liu, Yihang; Liu, Qingzhou; Zhou, Chongwu

2017-02-28

Semiconducting single-wall carbon nanotubes are ideal semiconductors for printed thin-film transistors due to their excellent electrical performance and intrinsic printability with solution-based deposition. However, limited by resolution and registration accuracy of current printing techniques, previously reported fully printed nanotube transistors had rather long channel lengths (>20 μm) and consequently low current-drive capabilities (<0.2 μA/μm). Here we report fully inkjet printed nanotube transistors with dramatically enhanced on-state current density of ∼4.5 μA/μm by downscaling the devices to a sub-micron channel length with top-contact self-aligned printing and employing high-capacitance ion gel as the gate dielectric. Also, the printed transistors exhibited a high on/off ratio of ∼10 5 , low-voltage operation, and good mobility of ∼15.03 cm 2 V -1 s -1 . These advantageous features of our printed transistors are very promising for future high-definition printed displays and sensing systems, low-power consumer electronics, and large-scale integration of printed electronics.

Chitosan-catechol: a writable bioink under serum culture media.

PubMed

Lee, Daiheon; Park, Joseph P; Koh, Mi-Young; Kim, Pureum; Lee, Junhee; Shin, Mikyung; Lee, Haeshin

2018-05-01

Mussel-inspired adhesive coatings on biomedical devices have attracted significant interest due to their unique properties such as substrate independency and high efficiency. The key molecules for mussel-inspired adhesive coatings are catechol and amine groups. Along with the understanding of catechol chemistry, chitosan-catechol has also been developed as a representative mussel-inpired adhesive polymer that contains catechol and amine groups for adhesiveness. Herein, we demonstrated the direct writability of chitosan-catechol as a bioink for 3D printing, one of the additive techniques. The use of chitosan-catechol bioink results in the formation of 3D constructs in normal culture media via rapid complexation of this bioink with serum proteins; in addition, the metal/catechol combination containing tiny amounts of vanadyl ions, in which the ratio of metal to catechol is 0.0005, dramatically enhances the mechanical strength and printability of the cell-encapsulated inks, showing a cell viability of approximately 90%. These findings for mussel-inspired bioinks will be a promising way to design a biocompatible 3D bioink cross-linked without any external stimuli.

Increasing Full Child Immunization Rates by Government Using an Innovative Computerized Immunization Due List in Rural India

PubMed Central

Gupta, Rahul; Reddy, R. Purushotham; Balasubramanian, K.; Reddy, P. S.

2018-01-01

Increasing child vaccination coverage to 85% or more in rural India from the current level of 50% holds great promise for reducing infant and child mortality and improving health of children. We have tested a novel strategy called Rural Effective Affordable Comprehensive Health Care (REACH) in a rural population of more than 300 000 in Rajasthan and succeeded in achieving full immunization coverage of 88.7% among children aged 12 to 23 months in a short span of less than 2 years. The REACH strategy was first developed and successfully implemented in a demonstration project by SHARE INDIA in Medchal region of Andhra Pradesh, and was then replicated in Rajgarh block of Rajasthan in cooperation with Bhoruka Charitable Trust (private partners of Integrated Child Development Services and National Rural Health Mission health workers in Rajgarh). The success of the REACH strategy in both Andhra Pradesh and Rajasthan suggests that it could be successfully adopted as a model to enhance vaccination coverage dramatically in other areas of rural India. PMID:29359630

Establishing the behavioural limits for countershaded camouflage.

PubMed

Penacchio, Olivier; Harris, Julie M; Lovell, P George

2017-10-20

Countershading is a ubiquitous patterning of animals whereby the side that typically faces the highest illumination is darker. When tuned to specific lighting conditions and body orientation with respect to the light field, countershading minimizes the gradient of light the body reflects by counterbalancing shadowing due to illumination, and has therefore classically been thought of as an adaptation for visual camouflage. However, whether and how crypsis degrades when body orientation with respect to the light field is non-optimal has never been studied. We tested the behavioural limits on body orientation for countershading to deliver effective visual camouflage. We asked human participants to detect a countershaded target in a simulated three-dimensional environment. The target was optimally coloured for crypsis in a reference orientation and was displayed at different orientations. Search performance dramatically improved for deviations beyond 15 degrees. Detection time was significantly shorter and accuracy significantly higher than when the target orientation matched the countershading pattern. This work demonstrates the importance of maintaining body orientation appropriate for the displayed camouflage pattern, suggesting a possible selective pressure for animals to orient themselves appropriately to enhance crypsis.

State-Of-The-Science Review: Everything NanoSilver and More

EPA Science Inventory

Silver has been known to be a potent antibacterial, antifungal and antiviral agent, but in recent years, the use of silver as a biocide in solution, suspension, and especially in nano-particulate form has experienced a dramatic revival. Due to the properties of silver at the nano...

Vector-borne viruses of pulse crops, with a particular emphasis on North American cropping systems

USDA-ARS?s Scientific Manuscript database

Pulse crop production in the USA has increased dramatically over the past decade, in part due to their nutritional value and ability to form symbiotic associations with rhizobacteria that fix atmospheric nitrogen. There are several insect-transmitted viruses that are prevalent and periodically quite...

Athletics and Students with Disabilities: What Principals Should Know

ERIC Educational Resources Information Center

Losinski, Mickey; Katsiyannis, Antonis; Yell, Mitchell L.

2014-01-01

Public concern over the general health of children in the United States has risen during recent years due to dramatic decreases in physical activity levels and increases in obesity and other health-related issues. This article examines the participation of students with disabilities in extracurricular activities, particularly athletic activities,…

DEVELOPMENT OF AN EPA METHOD FOR PERFLUOROCALKYL COMPOUNDS IN DRINKING WATER

EPA Science Inventory

Perfluoroalkyl compounds (PFCs) have been manufactured for over 50 years and their use has dramatically increased over the years. Due to their unique properties of repelling both water and oil, PFCs have been used in a wide variety of applications. In 2001, identification of or...

Reactive Attachment Disorder: Implications for School Readiness and School Functioning

ERIC Educational Resources Information Center

Schwartz, Eric; Davis, Andrew S.

2006-01-01

School readiness and functioning in children diagnosed with Reactive Attachment Disorder (RAD) are important issues due to the dramatic impact RAD has on multiple areas of development. The negative impact of impaired or disrupted early relationships, characterized by extreme neglect, abuse, parental mental illness, domestic violence, and repeated…

On quantifying active soil carbon using mid-infrared spectroscopy

USDA-ARS?s Scientific Manuscript database

Soil organic matter (SOM) is derived from plant or animal residues deposited on or in soil and is in various stages of decomposition and mineralization. Total SOM is a common measure of soil quality, although due to its heterogeneous composition SOM can vary dramatically in terms of its biochemical...

Assessing transportation infrastructure impacts on rangelands: Test of a standard rangeland assessment protocol

USDA-ARS?s Scientific Manuscript database

Linear disturbances associated with on and off-road vehicle use on rangelands has increased dramatically throughout the world in recent decades. This increase is due to a variety of factors including increased availability of all-terrain vehicles, infrastructure development (oil, gas, renewable ene...

Stratification of soil chemical and microbial properties under no-till management after lime amendment

USDA-ARS?s Scientific Manuscript database

Adoption of no-till (NT) technology in the dryland cropping region of the inland Pacific Northwest (iPNW) has dramatically reduced soil erosion compared to conventional tillage. Soils under continuous NT, however, often produce stratified soil acidification compared with conventional tillage due to ...

Soil carbon in natural, cultivated, and restored depressional wetlands in the Mid-Atlantic Coastal Plain

USDA-ARS?s Scientific Manuscript database

Aerial extent of wetland ecosystems have decreased dramatically since precolonial times due to the conversion of these areas for human use. Wetlands provide various ecosystem services, and conservation efforts are being made to restore wetlands and their functions, including soil carbon storage. Thi...

Autonomous measurements of bridge pier and abutment scour using motion-sensing radio transmitters : technical transfer summary.

DOT National Transportation Integrated Search

2010-01-01

Scour around the foundations (piers and abutments) of a bridge due to river flow is often referred to as bridge scour. Bridge scour is a problem of national scope that has dramatic impacts on economics and safety of the traveling public. Bridge...

Nutritional impacts on gene expression in the surface mucosa of blue catfish (Ictalurus furcatus)

USDA-ARS?s Scientific Manuscript database

Short-term feed deprivation is a common occurrence in both wild and farmed fish species, due to reproductive processes, seasonal variations in temperature, or in response to a disease outbreak. Fasting can have dramatic physiological and biological onsequences for fish, including impacts on mucosal ...

Health effects of Vaccinium myrtillus L.: evaluation of efficacy and technological strategies for preservation of active ingredients.

PubMed

Smeriglio, Antonella; Monteleone, Domenico; Trombetta, Domenico

2014-01-01

Bilberries are a rich dietary source of various phytonutrients, including anthocyanins which contribute greatly to their antioxidant capacity and have demonstrated a broad spectrum of biomedical functions. These include protection against cardiovascular disorders, age-induced oxidative stress, inflammatory responses and several degenerative diseases. Berry anthocyanins also improve neuronal and cognitive brain functions, ocular health as well as protecting genomic DNA integrity. In recent years, sales of many dietary supplements/pharmaceutical products containing anthocyanins in various dosages and formulations have been made by advertising their wide range of beneficial effects. However, there is a heightened risk of distributing deteriorated formulations to consumers due to lax regulations, in particular those applicable to phytochemical characterization and extract standardization, and in terms of quality regarding the stability of anthocyanins. Anthocyanin pigments readily degrade during industrial processing and this can have a dramatic impact on color quality and may also affect nutritional/pharmaceutical properties. This review aims to summarize the main health effects of bilberry extract used in several food supplements/pharmaceutical formulations focusing on some important aspects of anthocyanin degradation during processing and storage. It will also describe the main technological strategies which can give active ingredients greater stability, solubility and dispersibility in order to enhance formulation quality which is of great interest to the consumer and industry due to its direct and indirect impact on consumer health.

Synergistic foaming and surface properties of a weakly interacting mixture of soy glycinin and biosurfactant stevioside.

PubMed

Wan, Zhi-Li; Wang, Li-Ying; Wang, Jin-Mei; Yuan, Yang; Yang, Xiao-Quan

2014-07-16

The adsorption of the mixtures of soy glycinin (11S) with a biosurfactant stevioside (STE) at the air-water interface was studied to understand its relation with foaming properties. A combination of several techniques such as dynamic surface tension, dilatational rheology, fluorescence spectroscopy, and isothermal titration calorimetry (ITC) was used. In the presence of intermediate STE concentrations (0.25-0.5%), the weak binding of STE with 11S in bulk occurred by hydrophobic interactions, which could induce conformational changes of 11S, as evidenced by fluorescence and ITC. Accordingly, the strong synergy in reducing surface tension and the plateau in surface elasticity for mixed 11S-STE layers formed from the weakly interacting mixtures were clearly observed. This effect could be explained by the complexation with STE, which might facilitate the partial dissociation and further unfolding of 11S upon adsorption, thus enhancing the protein-protein and protein-STE interfacial interactions. These surface properties were positively reflected in foams produced by the weakly interacting system, which exhibited good foaming capacity and considerable stability probably due to better response to external stresses. However, at high STE concentrations (1-2%), as a consequence of the interface dominated by STE due to the preferential adsorption of STE molecules, the surface elasticity of layers dramatically decreased, and the resultant foams became less stable.

Optimized Lentiviral Vector Design Improves Titer and Transgene Expression of Vectors Containing the Chicken β-Globin Locus HS4 Insulator Element

PubMed Central

Hanawa, Hideki; Yamamoto, Motoko; Zhao, Huifen; Shimada, Takashi; Persons, Derek A

2009-01-01

Hematopoietic cell gene therapy using retroviral vectors has achieved success in clinical trials. However, safety issues regarding vector insertional mutagenesis have emerged. In two different trials, vector insertion resulted in the transcriptional activation of proto-oncogenes. One strategy for potentially diminishing vector insertional mutagenesis is through the use of self-inactivating lentiviral vectors containing the 1.2-kb insulator element derived from the chicken β-globin locus. However, use of this element can dramatically decrease both vector titer and transgene expression, thereby compromising its practical use. Here, we studied lentiviral vectors containing either the full-length 1.2-kb insulator or the smaller 0.25-kb core element in both orientations in the partially deleted long-terminal repeat. We show that use of the 0.25-kb core insulator rescued vector titer by alleviating a postentry block to reverse transcription associated with the 1.2-kb element. In addition, in an orientation-dependent manner, the 0.25-kb core element significantly increased transgene expression from an internal promoter due to improved transcriptional termination. This element also demonstrated barrier activity, reducing variability of expression due to position effects. As it is known that the 0.25-kb core insulator has enhancer-blocking activity, this particular insulated lentiviral vector design may be useful for clinical application. PMID:19223867

Chlorobenzene degeradation by non-thermal plasma combined with EG-TiO2/ZnO as a photocatalyst: Effect of photocatalyst on CO2 selectivity and byproducts reduction.

PubMed

Ghorbani Shahna, Farshid; Bahrami, Abdulrahman; Alimohammadi, Iraj; Yarahmadi, Rassuol; Jaleh, Babak; Gandomi, Mastaneh; Ebrahimi, Hossein; Ad-Din Abedi, Kamal

2017-02-15

The non-thermal plasma (NTP) technique, which suffers from low selectivity in complete oxidation of volatile organic compounds to CO 2 and H 2 O, creates unwanted and harmful byproducts. NTP in concert with photocatalyst can resolve this limitation due to additional oxidation. TiO 2 and ZnO nanoparticles were coated on the surface of the expanded graphite and placed downstream of the NTP reactor under UV light. In this study, to compare the performance of NTP and the combined system, chlorobenzene removal, selectivity of CO 2 and byproducts formation were investigated. The results showed that the combined system enhanced both the removal efficiency and CO 2 selectivity. The output gas of the NTP reactor contained chlorobenzene, phosgene, O 3 , NO, NO 2 , CO, CO 2 , HCL and CL. The bulk of these byproducts was oxidized on the surface of the nanocomposite; as a result, the content of the byproducts in the output gas of the combined system decreased dramatically. The removal efficiency and CO 2 selectivity increased by rising the applied voltage and residence time because the collision between active species and pollutant molecules increases. Based on these results, the combined system is preferred due to a higher performance and lower formation of harmful byproducts. Copyright © 2016 Elsevier B.V. All rights reserved.

Surface Deformation Observed by InSAR due to Fluid Injection: a Test Study in the Central U.S.

NASA Astrophysics Data System (ADS)

Deng, F.; Dixon, T. H.

2017-12-01

The central and eastern U.S. has undergone a dramatic increase in seismicity over the past few years. Many of these recent earthquakes were likely induced by human activities, with underground fluid injection for oil and gas extraction being one of the main contributors. Surface deformation caused by fluid injection has been captured by GPS and InSAR observations in several areas. For example, surface uplift of up to 10 cm due to CO2 injection between 2007 and 2011 was measured by InSAR at an enhanced oil recovery site in west Texas. We are using Texas and Oklahoma as test areas to analyze the potential relationship between surface deformation, underground fluid injection and induced earthquakes. C-band SAR data from ENVISAT and Sentinel-1, and L-band SAR data from ALOS and ALOS-2 are used to form decade-long time series. Based on the surface deformation derived from the time series InSAR data, subsurface volume change and volumetric strain in an elastic half space are estimated. Seismic data provided by the USGS are used to analyze the spatial and temporal distribution pattern of earthquakes, and the potential link between surface deformation and induced earthquakes. The trigger mechanism will be combined with forward modeling to predict seismicity and assess related hazard for future study.

Effect of various gases and chemical catalysts on phenol degradation pathways by pulsed electrical discharges.

PubMed

Shen, Yongjun; Lei, Lecheng; Zhang, Xingwang; Zhou, Minghua; Zhang, Yi

2008-02-11

The processes of phenol degradation by pulsed electrical discharges were investigated under several kinds of discharge atmospheres (oxygen, argon, nitrogen and ozone) and chemical catalysts (ferrous ion and hydrogen peroxide). The temporal variations of the concentrations of phenol and the intermediate products were monitored by HPLC and GC-MS, respectively. It has been found that the effect of various gases bubbling on phenol degradation rate ranked in the following order: oxygen-containing ozone>oxygen>argon>nitrogen. The high gas bubbling flow rate was beneficial to the removal of phenol. It was found that the degradation proceeded differently when in the presence and absence of catalysts. The phenol removal rate was increased when ferrous ion was added. This considerable enhancement may be due to the Fenton's reaction. What's more, putting the chemical additives hydrogen peroxide into the reactor led to a dramatic increase in phenol degradation rate. The mechanism was due to the direct or indirect photolysis and pyrolysis destruction in plasma channel. Furthermore, the intermediate products were monitored by GC-MS under three degradation conditions. More THBs were generated under degradation conditions without gases bubbling or adding any catalyst, and more DHBs under the condition of adding ferrous ion, and more carboxylic acids under the condition of oxygen-containing ozone gas bubbling. Consequently, three distinct degradation pathways based on different conditions were proposed.

Revealing giant internal magnetic fields due to spin fluctuations in magnetically doped colloidal nanocrystals

DOE PAGES

Rice, William D.; Liu, Wenyong; Baker, Thomas A.; ...

2015-11-23

Strong quantum confinement in semiconductors can compress the wavefunctions of band electrons and holes to nanometre-scale volumes, significantly enhancing interactions between themselves and individual dopants. In magnetically doped semiconductors, where paramagnetic dopants (such as Mn 2+, Co 2+ and so on) couple to band carriers via strong sp–d spin exchange, giant magneto-optical effects can therefore be realized in confined geometries using few or even single impurity spins. Importantly, however, thermodynamic spin fluctuations become increasingly relevant in this few-spin limit. In nanoscale volumes, the statistical √N fluctuations of N spins are expected to generate giant effective magnetic fields B eff, whichmore » should dramatically impact carrier spin dynamics, even in the absence of any applied field. In this paper, we directly and unambiguously reveal the large B eff that exist in Mn 2+-doped CdSe colloidal nanocrystals using ultrafast optical spectroscopy. At zero applied magnetic field, extremely rapid (300–600 GHz) spin precession of photoinjected electrons is observed, indicating B eff ~ 15-30 T for electrons. Precession frequencies exceed 2 THz in applied magnetic fields. Finally, these signals arise from electron precession about the random fields due to statistically incomplete cancellation of the embedded Mn 2+ moments, thereby revealing the initial coherent dynamics of magnetic polaron formation, and highlighting the importance of magnetization fluctuations on carrier spin dynamics in nanomaterials.« less

g-C{sub 3}N{sub 4}/NaTaO{sub 3} organic–inorganic hybrid nanocomposite: High-performance and recyclable visible light driven photocatalyst

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Santosh; Kumar, Bharat; Surendar, T.

2014-01-01

Graphical abstract: High-performance and recyclable visible-light driven g-C{sub 3}N{sub 4}/NaTaO{sub 3} hybrid nanocomposite photocatalysts have been prepared by a facile ultrasonic dispersion method. The hybrid nanocomposite photocatalyst can be promising photocatalytic material for practical application in water splitting and environmental remediation. - Highlights: • Novel g-C{sub 3}N{sub 4}/NaTaO{sub 3} nanocomposites as a high performance and recyclable photocatalysts. • These catalysts exhibited significantly enhanced photocatalytic activity under UV–visible light irradiation. • More attractively, dramatic activity is generated under visible light irradiation due to the g-C{sub 3}N{sub 4} loaded. • Interestingly, the as-prepared hybrid nanocomposites possess high reusability. - Abstract: Novel g-C{submore » 3}N{sub 4}/NaTaO{sub 3} hybrid nanocomposites have been prepared by a facile ultrasonic dispersion method. Our results clearly show the formation of interface between NaTaO{sub 3} and g-C{sub 3}N{sub 4} and further loading of g-C{sub 3}N{sub 4} did not affect the crystal structure and morphology of NaTaO{sub 3}. The g-C{sub 3}N{sub 4}/NaTaO{sub 3} nanocomposites exhibited enhanced photocatalytic performance for the degradation of Rhodamine B under UV–visible and visible light irradiation compared to pure NaTaO{sub 3} and Degussa P25. Interestingly, the visible light photocatalytic activity is generated due to the loading of g-C{sub 3}N{sub 4}. A mechanism is proposed to discuss the enhanced photocatalytic activity based on trapping experiments of photoinduced radicals and holes. Under visible light irradiation, electron excited from the valance band (VB) to conduction band (CB) of g-C{sub 3}N{sub 4} could directly inject into the CB of NaTaO{sub 3}, making g-C{sub 3}N{sub 4}/NaTaO{sub 3} visible light driven photocatalyst. Since the as-prepared hybrid nanocomposites possess high reusability therefore it can be promising photocatalyst for environmental applications.« less

3.0-T functional brain imaging: a 5-year experience.

PubMed

Scarabino, T; Giannatempo, G M; Popolizio, T; Tosetti, M; d'Alesio, V; Esposito, F; Di Salle, F; Di Costanzo, A; Bertolino, A; Maggialetti, A; Salvolini, U

2007-02-01

The aim of this paper is to illustrate the technical, methodological and diagnostic features of functional imaging (comprising spectroscopy, diffusion, perfusion and cortical activation techniques) and its principal neuroradiological applications on the basis of the experience gained by the authors in the 5 years since the installation of a high-field magnetic resonance (MR) magnet. These MR techniques are particularly effective at 3.0 Tesla (T) owing to their high signal, resolution and sensitivity, reduced scanning times and overall improved diagnostic ability. In particular, the high-field strength enhances spectroscopic analysis due to a greater signal-to-noise ratio (SNR) and improved spectral, space and time resolution, resulting in the ability to obtain high-resolution spectroscopic studies not only of the more common metabolites, but also--and especially--of those which, due to their smaller concentrations, are difficult to detect using 1.5-T systems. All of these advantages can be obtained with reduced acquisition times. In diffusion studies, the high-field strength results in greater SNR, because 3.0-T magnets enable increased spatial resolution, which enhances accuracy. They also allow exploration in greater detail of more complex phenomena (such as diffusion tensor and tractography), which are not clearly depicted on 1.5-T systems. The most common perfusion study (with intravenous injection of a contrast agent) benefits from the greater SNR and higher magnetic susceptibility by achieving dramatically improved signal changes, and thus greater reliability, using smaller doses of contrast agent. Functional MR imaging (fMRI) is without doubt the modality in which high-field strength has had the greatest impact. Images acquired with the blood-oxygen-level-dependent (BOLD) technique benefit from the greater SNR afforded by 3.0-T magnets and from their stronger magnetic susceptibility effects, providing higher signal and spatial resolution. This enhances reliability of the localisation of brain functions, making it possible to map additional areas, even in the millimetre and submillimetre scale. The data presented and results obtained to date show that 3.0-T morphofunctional imaging can become the standard for high-resolution investigation of brain disease.

Yeast adapt to near-freezing temperatures by STRE/Msn2,4-dependent induction of trehalose synthesis and certain molecular chaperones.

PubMed

Kandror, Olga; Bretschneider, Nancy; Kreydin, Evgeniy; Cavalieri, Duccio; Goldberg, Alfred L

2004-03-26

Virtually nothing is known about the biochemical adaptations in eukaryotic cells that may enhance survival at low temperatures or upon freezing. Here we demonstrate an adaptive response in yeast that is activated below 10 degrees C and increases tolerance to low temperatures and freezing. This response involves a dramatic accumulation of the chemical chaperone trehalose and induction of trehalose-synthesizing enzymes (Tps1, Tps2) and certain heat shock proteins (Hsp104, Hsp42, Hsp12, Ssa4). mRNAs for these proteins increase dramatically below 10 degrees C and even at 0 degrees C. Their expression requires Msn2,4 transcription factors but also involves marked mRNA stabilization. Upon return to 30 degrees C, TPS1, TPS2, and HSP104 mRNAs, trehalose levels and tolerance to freezing fall dramatically within minutes. Mutants lacking trehalose or Msn2,4 die more rapidly at 0 degrees C and upon freezing. Thus, below 10 degrees C, yeast show an adaptive response that sustains viability at low or freezing temperatures, which are commonly encountered in natural environments and laboratory refrigerators.

Dramatic Influence of an Anionic Donor on the Oxygen-Atom Transfer Reactivity of a MnV–Oxo Complex

PubMed Central

Neu, Heather M; Quesne, Matthew G; Yang, Tzuhsiung; Prokop-Prigge, Katharine A; Lancaster, Kyle M; Donohoe, James; DeBeer, Serena; de Visser, Sam P; Goldberg, David P

2014-01-01

Addition of an anionic donor to an MnV(O) porphyrinoid complex causes a dramatic increase in 2-electron oxygen-atom-transfer (OAT) chemistry. The 6-coordinate [MnV(O)(TBP8Cz)(CN)]− was generated from addition of Bu4N+CN− to the 5-coordinate MnV(O) precursor. The cyanide-ligated complex was characterized for the first time by Mn K-edge X-ray absorption spectroscopy (XAS) and gives Mn–O=1.53 Å, Mn–CN=2.21 Å. In combination with computational studies these distances were shown to correlate with a singlet ground state. Reaction of the CN− complex with thioethers results in OAT to give the corresponding sulfoxide and a 2e−-reduced MnIII(CN)− complex. Kinetic measurements reveal a dramatic rate enhancement for OAT of approximately 24 000-fold versus the same reaction for the parent 5-coordinate complex. An Eyring analysis gives ΔH≠=14 kcal mol−1, ΔS≠=−10 cal mol−1 K−1. Computational studies fully support the structures, spin states, and relative reactivity of the 5- and 6-coordinate MnV(O) complexes. PMID:25256417

Pumped shot noise in adiabatically modulated graphene-based double-barrier structures.

PubMed

Zhu, Rui; Lai, Maoli

2011-11-16

Quantum pumping processes are accompanied by considerable quantum noise. Based on the scattering approach, we investigated the pumped shot noise properties in adiabatically modulated graphene-based double-barrier structures. It is found that compared with the Poisson processes, the pumped shot noise is dramatically enhanced where the dc pumped current changes flow direction, which demonstrates the effect of the Klein paradox.

Pumped shot noise in adiabatically modulated graphene-based double-barrier structures

NASA Astrophysics Data System (ADS)

Zhu, Rui; Lai, Maoli

2011-11-01

Quantum pumping processes are accompanied by considerable quantum noise. Based on the scattering approach, we investigated the pumped shot noise properties in adiabatically modulated graphene-based double-barrier structures. It is found that compared with the Poisson processes, the pumped shot noise is dramatically enhanced where the dc pumped current changes flow direction, which demonstrates the effect of the Klein paradox.

Activation of beta2-Adrenoceptor Enhances Synaptic Potentiation and Behavioral Memory via cAMP-PKA Signaling in the Medial Prefrontal Cortex of Rats

ERIC Educational Resources Information Center

Zhou, Hou-Cheng; Sun, Yan-Yan; Cai, Wei; He, Xiao-Ting; Yi, Feng; Li, Bao-Ming; Zhang, Xue-Han

2013-01-01

The prefrontal cortex (PFC) plays a critical role in cognitive functions, including working memory, attention regulation, behavioral inhibition, as well as memory storage. The functions of PFC are very sensitive to norepinephrine (NE), and even low levels of endogenously released NE exert a dramatic influence on the functioning of the PFC.…

The Evaluation of a Food Allergy and Epinephrine Autoinjector Training Program for Personnel Who Care for Children in Schools and Community Settings

ERIC Educational Resources Information Center

Wahl, Ann; Stephens, Hilary; Ruffo, Mark; Jones, Amanda L.

2015-01-01

With the dramatic increase in the incidence of food allergies, nurses and other school personnel are likely to encounter a child with food allergies. The objectives of this study were to assess the effectiveness of in-person training on enhancing knowledge about food allergies and improving self-confidence in preventing, recognizing, and treating…

What We Know about the Dramatic Increase in PhD Degrees and the Reform of Doctoral Education Worldwide: Implications for South Africa

ERIC Educational Resources Information Center

Nerad, Maresi

2011-01-01

Theories of the "knowledge economy" view knowledge, and particularly new knowledge, as a critical resource to enhance a nation's economic growth. Governments around the world have invested in doctoral education expansion. Reforms in doctoral education are being shaped by the changing needs of society, of research modes, and of a changed…

Infrared imaging enhances retinal crystals in Bietti’s crystalline dystrophy

PubMed Central

Brar, Vikram S; Benson, William H

2015-01-01

Infrared imaging dramatically increased the number of crystalline deposits visualized compared with clinical examination, standard color fundus photography, and red free imaging in patients with Bietti’s crystalline dystrophy. We believe that this imaging modality significantly improves the sensitivity with which these lesions are detected, facilitating earlier diagnosis and may potentially serve as a prognostic indicator when examined over time. PMID:25931805

The Role Biomedical Science Laboratories Can Play in Improving Science Knowledge and Promoting First-Year Nursing Academic Success

ERIC Educational Resources Information Center

Arneson, Pam

2011-01-01

The need for additional nursing and health care professionals is expected to increase dramatically over the next 20 years. With this in mind, students must have strong biomedical science knowledge to be competent in their field. Some studies have shown that participation in bioscience laboratories can enhance science knowledge. If this is true, an…

Enhancing the Competitiveness of Vietnamese Industry Through Trade Liberalization

DTIC Science & Technology

2013-11-01

This effort was progressing well and gathering momentum up until 2008, but it slowed dramatically under the impact of the global economic slowdown...international trade. The TPP is expected have positive economic impacts for all participants and benefit Vietnam the most with an estimated 14...Vietnamese enterprises. Adjusting accounting standards to converge with IFRS will create confidence in financial analysis and allow for global comparisons

Angiogenin Defines Heterogeneity at the Core of the Hematopoietic Niche.

PubMed

Di Scala, Marianna; Hidalgo, Andrés

2016-09-01

Successful hematopoietic regeneration demands preservation of stemness while enabling expansion and differentiation into blood lineages. Now, Silberstein et al. (2016) and Goncalves et al. (2016) identify a ribonuclease secreted by proximal niche cells that simultaneously drives quiescence of HSCs and proliferation of myeloid progenitors and dramatically enhances hematopoietic recovery after HSC transplantation. Copyright © 2016 Elsevier Inc. All rights reserved.

High-Throughput Fabrication of Ultradense Annular Nanogap Arrays for Plasmon-Enhanced Spectroscopy.

PubMed

Cai, Hongbing; Meng, Qiushi; Zhao, Hui; Li, Mingling; Dai, Yanmeng; Lin, Yue; Ding, Huaiyi; Pan, Nan; Tian, Yangchao; Luo, Yi; Wang, Xiaoping

2018-06-13

The confinement of light into nanometer-sized metallic nanogaps can lead to an extremely high field enhancement, resulting in dramatically enhanced absorption, emission, and surface-enhanced Raman scattering (SERS) of molecules embedded in nanogaps. However, low-cost, high-throughput, and reliable fabrication of ultra-high-dense nanogap arrays with precise control of the gap size still remains a challenge. Here, by combining colloidal lithography and atomic layer deposition technique, a reproducible method for fabricating ultra-high-dense arrays of hexagonal close-packed annular nanogaps over large areas is demonstrated. The annular nanogap arrays with a minimum diameter smaller than 100 nm and sub-1 nm gap width have been produced, showing excellent SERS performance with a typical enhancement factor up to 3.1 × 10 6 and a detection limit of 10 -11 M. Moreover, it can also work as a high-quality field enhancement substrate for studying two-dimensional materials, such as MoSe 2 . Our method provides an attractive approach to produce controllable nanogaps for enhanced light-matter interaction at the nanoscale.

Ensemble brightening and enhanced quantum yield in size-purified silicon nanocrystals

DOE PAGES

Miller, Joseph B.; Van Sickle, Austin R.; Anthony, Rebecca J.; ...

2012-07-18

Here, we report on the quantum yield, photoluminescence (PL) lifetime and ensemble photoluminescent stability of highly monodisperse plasma-synthesized silicon nanocrystals (SiNCs) prepared though density-gradient ultracentrifugation in mixed organic solvents. Improved size uniformity leads to a reduction in PL line width and the emergence of entropic order in dry nanocrystal films. We find excellent agreement with the anticipated trends of quantum confinement in nanocrystalline silicon, with a solution quantum yield that is independent of nanocrystal size for the larger fractions but decreases dramatically with size for the smaller fractions. We also find a significant PL enhancement in films assembled from themore » fractions, and we use a combination of measurement, simulation and modeling to link this ‘brightening’ to a temporally enhanced quantum yield arising from SiNC interactions in ordered ensembles of monodisperse nanocrystals. Using an appropriate excitation scheme, we exploit this enhancement to achieve photostable emission.« less

Effects of ball milling on the physicochemical and sorptive properties of biochar: Experimental observations and governing mechanisms.

PubMed

Lyu, Honghong; Gao, Bin; He, Feng; Zimmerman, Andrew R; Ding, Cheng; Huang, Hua; Tang, Jingchun

2018-02-01

With the goal of combining the advantages of ball-milling and biochar technologies, a variety of ball-milled biochars (BM-biochars) were synthesized, characterized, and tested for nickel (Ni(II)) removal from aqueous solution. Ball milling increased only the external surface area of low temperature biochars, but still dramatically enhanced their ability to sorb aqueous Ni(II). For higher temperature biochars with relatively low surface area, ball milling increased both external and internal surface area. Measurements of pH, zeta potential, stability, and Boehm titration demonstrated that ball milling also added oxygen-containing functional groups (e.g., carboxyl, lactonic, and hydroxyl) to biochar's surface. With these changed, all the BM-biochars showed much better Ni(II) removal efficiency than unmilled biochars. Ball-milled 600 °C bagasse biochar (BMBG600) showed the greatest Ni(II) adsorption capacity (230-650 compared to 26-110 mmol/kg for unmilled biochar) and the adsorption was dosage and pH dependent. Compared with the unmilled biochar, BMBG600 also displayed faster adsorption kinetics, likely due to an increase in rates of intra-particle diffusion in the latter. Experimental and modeling results suggest that the increase in BM-biochar's external and internal surface areas exposed its graphitic structure, thus enhancing Ni(II) adsorption via strong cation-π interaction. In addition, the increase in acidic surface functional groups enhanced Ni(II) adsorption by BM-biochar via electrostatic interaction and surface complexation. Ball milling thus has great potential to increase the efficiency of environmentally friendly biochar for various environmental applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Oral bioavailability enhancement of β-lapachone, a poorly soluble fast crystallizer, by cocrystal, amorphous solid dispersion, and crystalline solid dispersion.

PubMed

Liu, Chengyu; Liu, Zhengsheng; Chen, Yuejie; Chen, Zhen; Chen, Huijun; Pui, Yipshu; Qian, Feng

2018-03-01

The aim of this paper was to compare the in vitro dissolution and in vivo bioavailability of three solubility enhancement technologies for β-lapachone (LPC), a poorly water soluble compound with extremely high crystallization propensity. LPC cocrystal was prepared by co-grinding LPC with resorcinol. LPC crystalline and amorphous solid dispersions (CSD and ASD) were obtained by spray drying with Poloxamer 188 and HPMC-AS, respectively. The cocrystal structure was solved by single crystal x-ray diffraction. All formulations were characterized by WAXRD, DSC, POM and SEM. USP II and intrinsic dissolution studies were used to compare the in vitro dissolution of these formulations, and a crossover dog pharmacokinetic study was used to compare their in vivo bioavailability. An 1:1 LPC-resorcinol cocrystal with higher solubility and faster dissolution rate was obtained, yet it converted to LPC crystal rapidly in solution. LPC/HPMC-AS ASD was confirmed to be amorphous and uniform, while the crystal and crystallite sizes of LPC in CSD were found to be ∼1-3 μm and around 40 nm, respectively. These formulations performed similarly during USP II dissolution, while demonstrated dramatically different oral bioavailability of ∼32%, ∼5%, and ∼1% in dogs, for CSD, co-crystal, and ASD, respectively. CSD showed the fastest intrinsic dissolution rate among the three. The three formulations showed poor IVIVC which could be due to rapid and unpredictable crystallization kinetics. Considering all the reasons, we conclude that for molecules with extremely high crystallization tendency that cannot be inhibited by any pharmaceutical excipients, size-reduction technologies such as CSD could be advantageous for oral bioavailability enhancement in vivo than technologies only generating transient but not sustained supersaturation. Copyright © 2018 Elsevier B.V. All rights reserved.

FirnCover: Observations on the evolution of firn compaction, firn temperatures and porosity in the interior of the Greenland ice sheet

NASA Astrophysics Data System (ADS)

MacFerrin, M. J.; Stevens, C.; Colgan, W. T.; Waddington, E. D.; Abdalati, W.

2016-12-01

As Greenland warms, increasing amounts of summer meltwater are changing the behavior of snow and firn in high-elevation regions of the ice. The Firn Compaction Verification and Reconnaissance (FirnCover) network in Greenland provides real-time measurements of compaction, firn temperatures and other observations across Greenland's interior, ranging from regions of dry snow to areas of heavy melt and refreezing. Here we present results from FirnCover measurements that illustrate a distinct shift in seasonal thermal cycles within the firn in regions with increased melt, whereby seasonal temperature cycles are both enhanced (in magnitude) and delayed (in timing) in response to increased latent heat from refreezing. Seasonal firn-compaction rates correlate strongly with these thermal cycles. Comparisons to historical cores illustrate that despite warming temperatures, compaction rates have not changed substantially in dry-snow regions of Greenland where meltwater has not yet been generated to a significant degree. In regions with enhanced melt and refreezing, historical comparisons indicate annual rates of compaction have dramatically increased in recent decades. In regions where near-surface firn has exceeded a critical saturation cutoff, water has begun to run off downhill rather than refreezing in years of high melt. In such regions these seasonal thermal cycles (and corresponding compaction rates) are greatly reduced due to the isolation of deep firn from meltwater above. We present current observations that suggest such saturated regions are rapidly expanding in Greenland in response to warming and enhanced summer melt. We outline the strong implications these observations have for interpreting Greenland's seasonal and inter-annual mass balance from airborne and satellite altimetry, as well as for the future evolution of runoff from Greenland's interior in a warming climate.

Activation of EVI1 transcription by the LEF1/β-catenin complex with p53-alteration in myeloid blast crisis of chronic myeloid leukemia.

PubMed

Manachai, Nawin; Saito, Yusuke; Nakahata, Shingo; Bahirvani, Avinash Govind; Osato, Motomi; Morishita, Kazuhiro

2017-01-22

The presence of a BCR-ABL1 fusion gene is necessary for the pathogenesis of chronic myeloid leukemia (CML) through t(9;22)(q34;q11) translocation. Imatinib, an ABL tyrosine kinase inhibitor, is dramatically effective in CML patients; however, 30% of CML patients will need further treatment due to progression of CML to blast crisis (BC). Aberrant high expression of ecotropic viral integration site 1 (EVI1) is frequently observed in CML during myeloid-BC as a potent driver with a CML stem cell signature; however, the precise molecular mechanism of EVI1 transcriptional regulation during CML progression is poorly defined. Here, we demonstrate the transcriptional activity of EVI1 is dependent on activation of lymphoid enhancer-binding factor 1 (LEF1)/β-catenin complex by BCR-ABL with loss of p53 function during CML-BC. The activation of β-catenin is partly dependent on BCR-ABL expression through enhanced GSK3β phosphorylation, and EVI1 expression is directly enhanced by the LEF1/β-catenin complex bound to the EVI1 promoter region. Moreover, the loss of p53 expression is inversely correlated with high expression of EVI1 in CML leukemia cells with an aggressive phase of CML, and a portion of the activation mechanism of EVI1 expression is dependent on β-catenin activation through GSK3β phosphorylation by loss of p53. Therefore, we found that the EVI1 activation in CML-BC is dependent on LEF1/β-catenin activation by BCR-ABL expression with loss of p53 function, representing a novel selective therapeutic approach targeting myeloid blast crisis progression. Copyright © 2016 Elsevier Inc. All rights reserved.

Carbonic anhydrase inhibition boosts the antitumor effects of Imatinib mesylate via potentiating the antiangiogenic and antimetastatic machineries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abd-El Fattah, Amal A.

2017-02-01

Carbonic anhydrase inhibitors have emerged in the past few years as an interesting candidate for the development of novel unconventional strategies. Despite their effect in tumor regression via inhibition of tumor acidification, their potential role is not yet fully elucidated. Herein, we investigated whether acetazolamide (AZ) could modulate imatinib (IM) anticancer activity, both in breast cancer cells (T47D) and in isolated tumor specimens of Ehrlich ascites carcinoma (EAC). The impact of this combination on angiogenesis was evidenced by decreasing PDGF-A expression and enhancing that of TSP-1. In the meantime, AZ significantly suppressed IM-induced attenuation of VEGF secretion in T47D cells,more » most probably due to NO inhibition. The combination also dramatically decreased the metastatic activity of T47D cells by mitigating the protein levels of MMP-2 and -9 and phosphorylation of p38 MAPK, while increasing the expression of TIMP-1 and -2. In addition, a strong proapoptotic effect was observed in T47D cells after combining AZ and IM in terms of increased caspase-9 and -3 activities. Interestingly, these results were confirmed by the reduction in the isolated tumor volume, MVD, Ki-67 and VEGF expression. Eventually, the study provides a new therapeutic strategy for treating cancer. - Highlights: • A novel combination of imatinib and a carbonic anhydrase was studied. • The impact was evaluated in T47D cells and EAC-bearing mice. • The interaction suppressed PDGF-A and VEGF while enhanced TSP-1. • MMPs and p38 MAPK phosphorylation were suppressed while TIMPs were enhanced. • The interaction triggered caspase-9 and -3 activation.« less

Why Henry III of Navarre’s Hair Probably did not Turn White Overnight

PubMed Central

Navarini, Alexander A; Trüeb, Ralph M

2010-01-01

Although a rare event, sudden whitening of hair (canities subita) has reportedly affected a number of well-known historical figures, usually in relation to dramatic events in their lives. Although early accounts are substantiated by more recent case reports in scientific literature, we suspect that the phenomenon is not only used as a literary means in fiction, with the aim of dramatizing, but probably also in historical accounts. For this purpose, we examine the case history of Henry III of Navarre who allegedly turned white on the evening of the Saint Bartholomew’s day massacre, and challenge this claim, due to inconsistencies in his biography, with the current pathophysiological understanding of canities subita. PMID:21188015

Why Atens Enjoy Enhanced Accessibility for Human Space Flight

NASA Technical Reports Server (NTRS)

Barbee, Brent W.; Adamo, Daniel R.

2011-01-01

Near-Earth objects can be grouped into multiple orbit classifications, among them being the Aten group, whose members have orbits crossing Earth's with semi-major axes less than 1 astronomical unit. Atens comprise well under 10% of known near-Earth objects. This is in dramatic contrast to results from recent human space flight near-Earth object accessibility studies, where the most favorable known destinations are typically almost 50% Atens. Geocentric dynamics explain this enhanced Aten accessibility and lead to an understanding of where the most accessible near-Earth objects reside. Without a comprehensive space-based survey, however, highly accessible Atens will remain largely unknown.

Bioenabled SERS Substrates for Food Safety and Drinking Water Monitoring.

PubMed

Yang, Jing; Rorrer, Gregory L; Wang, Alan X

2015-04-20

We present low-cost bioenabled surface-enhanced Raman scattering (SERS) substrates that can be massively produced in sustainable and eco-friendly methods with significant commercial potentials for the detection of food contamination and drinking water pollution. The sensors are based on diatom frustules with integrated plasmonic nanoparticles. The ultra-high sensitivity of the SERS substrates comes from the coupling between the diatom frustules and Ag nanoparticles to achieve dramatically increased local optical field to enhance the light-matter interactions for SERS sensing. We successfully applied the bioenabled SERS substrates to detect melamine in milk and aromatic compounds in water with sensitivity down to 1μg/L.

Dermatology practice management enhancement: implications for dermatology in the age of managed care.

PubMed

Nestor, M S

2000-09-01

Health care delivery in the United States has changed dramatically during the past 10 years. Dermatologists are faced with challenging changes in the way they learn new skills, practice, and provide dermatologic care. Dermatologists can survive and flourish in this environment if they learn proper management and enhancement skills. These skills include proper coding and documentation, regulatory compliance, and new levels of practice effectiveness and efficiency. Dermatologists can offer also the benefit of cosmetic procedures and ethical office-based dispensing to their patients. Greater future unification of this specialty will allow dermatology to flourish and show its need, efficiency, and cost-effectiveness.

He-3-rich flares - A possible explanation

NASA Technical Reports Server (NTRS)

Fisk, L. A.

1978-01-01

A plasma mechanism is proposed to explain the dramatic enhancements in He-3 observed in He-3-rich flares. It is shown that a common current instability in the corona may heat ambient He-3(2+) over any other ion and thus may preferentially inject He-3 into the flare acceleration process. This mechanism operates when the abundance of He-4 and heavier elements is larger than normal in the coronal plasma. It may also preferentially heat and thus inject certain ions of iron. The mechanism thus provides a possible explanation for the observed correlation between He-3 and heavy enhancements in He-3-rich flares.

Bioenabled SERS substrates for food safety and drinking water monitoring

NASA Astrophysics Data System (ADS)

Yang, Jing; Rorrer, Gregory L.; Wang, Alan X.

2015-05-01

We present low-cost bioenabled surface-enhanced Raman scattering (SERS) substrates that can be massively produced in sustainable and eco-friendly methods with significant commercial potentials for the detection of food contamination and drinking water pollution. The sensors are based on diatom frustules with integrated plasmonic nanoparticles. The ultra-high sensitivity of the SERS substrates comes from the coupling between the diatom frustules and Ag nanoparticles to achieve dramatically increased local optical field to enhance the light-matter interactions for SERS sensing. We successfully applied the bioenabled SERS substrates to detect melamine in milk and aromatic compounds in water with sensitivity down to 1μg/L.

Novel Highly Porous Metal Technology in Artificial Hip and Knee Replacement: Processing Methodologies and Clinical Applications

NASA Astrophysics Data System (ADS)

Muth, John; Poggie, Matthew; Kulesha, Gene; Michael Meneghini, R.

2013-02-01

Hip and knee replacement can dramatically improve a patient's quality of life through pain relief and restored function. Fixation of hip and knee replacement implants to bone is critical to the success of the procedure. A variety of roughened surfaces and three-dimensional porous surfaces have been used to enhance biological fixation on orthopedic implants. Recently, highly porous metals have emerged as versatile biomaterials that may enhance fixation to bone and are suitable to a number of applications in hip and knee replacement surgery. This article provides an overview of several processes used to create these implant surfaces.

Bioenabled SERS Substrates for Food Safety and Drinking Water Monitoring

PubMed Central

Yang, Jing; Rorrer, Gregory L.; Wang, Alan X.

2016-01-01

We present low-cost bioenabled surface-enhanced Raman scattering (SERS) substrates that can be massively produced in sustainable and eco-friendly methods with significant commercial potentials for the detection of food contamination and drinking water pollution. The sensors are based on diatom frustules with integrated plasmonic nanoparticles. The ultra-high sensitivity of the SERS substrates comes from the coupling between the diatom frustules and Ag nanoparticles to achieve dramatically increased local optical field to enhance the light-matter interactions for SERS sensing. We successfully applied the bioenabled SERS substrates to detect melamine in milk and aromatic compounds in water with sensitivity down to 1μg/L. PMID:26900205

Bulky Counterions: Enhancing the Two-Photon Excited Fluorescence of Gold Nanoclusters.

PubMed

Bertorelle, Franck; Moulin, Christophe; Soleilhac, Antonin; Comby-Zerbino, Clothilde; Dugourd, Philippe; Russier-Antoine, Isabelle; Brevet, Pierre-François; Antoine, Rodolphe

2018-01-19

Increasing fluorescence quantum yields of ligand-protected gold nanoclusters has attracted wide research interest. The strategy consisting in using bulky counterions has been found to dramatically enhance the fluorescence. In this Communication, we push forward this concept to the nonlinear optical regime. We show that by an appropriate choice of bulky counterions and of solvent, a 30-fold increase in two-photon excited fluorescence (TPEF) signal at ≈600 nm for gold nanoclusters can be obtained. This would correspond to a TPEF cross-section in the range of 0.1 to 1 GM. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of Sr and Bi on the Si(100) surface oxidation - Auger electron spectroscopy, low energy electron diffraction, and X-ray photoelectron spectroscopy study

NASA Technical Reports Server (NTRS)

Fan, W. C.; Mesarwi, A.; Ignatiev, A.

1990-01-01

The effect of Sr and Bi on the oxidation of the Si(100) surface has been studied by Auger electron spectroscopy, low electron diffraction, and X-ray photoelectron spectroscopy. A dramatic enhancement, by a factor of 10, of the Si oxidation has been observed for Si(100) with a Sr overlayer. The SR-enhanced Si oxidation has been studied as a function of O2 exposure and Sr coverage. In contrast to the oxidation promotion of Sr on Si, it has been also observed that a Bi overlayer on Si(100) reduced Si oxidation significantly. Sr adsorption on the Si(100) with a Bi overlayer enhances Si oxidation only at Sr coverage of greater than 0.3 ML.

Understanding Coastal Wetland Vulnerability to Sea-Level Rise Enhanced Inundation Using Real-Time Stage Monitoring, LiDAR, and Monte Carlo Simulation in Everglades National Park

NASA Astrophysics Data System (ADS)

Cooper, H.; Zhang, C.

2017-12-01

Coastal wetlands are one of the most productive ecological systems in the world, providing critical habitat area and valuable ecosystem services such as carbon sequestration. However, due to their location in low lying areas, coastal wetlands are particularly vulnerable to sea-level rise (SLR). Everglades National Park (ENP) encompasses the southern-most portion of the Greater Everglades Ecosystem, and is the largest subtropical wetland in the USA. Water depths have shown to have a significant relationship to vegetation community composition and organization while also playing a crucial role in vegetation health throughout the Everglades. Live plants play a vital role in maintaining soil structure (i.e. elevation), and decreases in vegetation health can cause peat collapse or wetland loss resulting in dramatic habitat, organic soil, and elevation loss posing concerns for Everglades management and restoration. One suspected mechanism for peat collapse is enhanced inundation due to SLR, thus mapping and modeling water depths is a critical component to understanding the potential impacts of future SLR. Previous research in the Everglades focused on a conventional Water Depth Model (WDM) approach where a Digital Elevation Model (DEM) is subtracted from a Water Table Elevation Model (WTEM). In this study, the conventional WDM approach is extended to a more rigorous WDM technique so that the accuracy and precision of the underlying data may be considered. Monte Carlo simulation is used to propagate probability distributions through our SLR depth model using our Random Forest-based LiDAR DEM, Empirical Bayesian Kriging-based WTEMs, uncertainties in vertical datums, soil accretion projections, and regional sea-level rise projections. Water depth maps were produced for the wet and dry seasons in April and October, which successfully revealed the potential spatial and temporal water depth variations due to future SLR. It is concluded that a more rigorous WDM technique helps to increase the integrity of derived products used to support and guide coastal restoration managers and planners under the challenge of rising seas.

Planning and Designing: The Future in Library Education.

ERIC Educational Resources Information Center

Boaz, Martha

By the year 2,000 numerous changes will make this world very different from today's society. Our economy will be based on education and service related jobs instead of product-production. The population will almost double, and leisure time will increase dramatically due to increased automation. Continuous learning, often outside the formal…

Social Class and Workplace Harassment during the Transition to Adulthood

ERIC Educational Resources Information Center

McLaughlin, Heather; Uggen, Christopher; Blackstone, Amy

2008-01-01

Young disadvantaged workers are especially vulnerable to harassment due to their age and social class position. As young people enter the workforce, their experiences of, and reactions to, harassment may vary dramatically from those of older adult workers. Three case studies introduce theory and research on the relationship between social class…

Paying to Listen: Notes from a Survey of Sexual Commerce

ERIC Educational Resources Information Center

Snow, Rachel C.; Williams, Angela; Collins, Curtis; Moorman, Jessica; Rangel, Tomas; Barick, Audrey; Clay, Crystal; Matiz Reyes, Armando

2013-01-01

As the study of sexual commerce has grown dramatically in recent decades due to interest in HIV/AIDS, an expanded literature has scrutinized how research teams manage the operational challenges of accessing spaces that typically resist scrutiny. This paper ventures a combination of both scholarly reflections on the utility of ethical listening and…

DATABASE OF LANDFILL GAS TO ENERGY PROJECTS IN THE UNITED STATES

EPA Science Inventory

The paper discusses factors influencing the increase of landfill gas to energy (LFG-E) projects in the U.S. and presents recent statistics from a database,. There has been a dramatic increase in the number of LFG-E projects in the U.S., due to such factors as implementation of t...

A Framework for Open Textbooks Analytics System

ERIC Educational Resources Information Center

Prasad, Deepak; Totaram, Rajneel; Usagawa, Tsuyoshi

2016-01-01

In the last few years, open textbook development has picked up dramatically due both to the expense of commercially published textbooks and the increasing availability of high-quality OER alternatives. While this offers a tremendous benefit in terms of lowering student textbook costs, the question remains, to what extent (if any) do open textbooks…

Mold inhibition on unseasoned southern pine

Treesearch

Carol A. Clausen; Vina W. Yang

2003-01-01

Concerns about indoor air quality due to mold growth have increased dramatically in the United States. In the absence of moisture management, fungicides need to be developed for indoor use to control mold establishment. An ideal fungicide for prevention of indoor mold growth on wood-based materials needs to specifically prevent spore germination and provide long-term...

New research and tools lead to improved earthquake alerting protocols

USGS Publications Warehouse

Wald, David J.

2009-01-01

What’s the best way to get alerted about the occurrence and potential impact of an earthquake? The answer to that question has changed dramatically of late, in part due to improvements in earthquake science, and in part by the implementation of new research in the delivery of earthquake information

Processing, quality and safety of irradiation - and high pressure processed meat and seafood products

USDA-ARS?s Scientific Manuscript database

In the past two decades, worldwide demands for meat and seafood products have increased dramatically due to the improved economical condition in many countries. To meet the demand, the producers have increased the production of meat and seafood products as well as applied new processing techniques t...

Whitebark and limber pine restoration and monitoring in Glacier National Park

Treesearch

Jennifer M. Asebrook; Joyce Lapp; Tara. Carolin

2011-01-01

Whitebark pine (Pinus albicaulis) and limber pine (Pinus flexilis) are keystone species important to watersheds, grizzly and black bears, squirrels, birds, and other wildlife. Both high elevation five-needled pines have dramatically declined in Glacier National Park primarily due to white pine blister rust (Cronartium ribicola) and fire exclusion, with mountain pine...

Left Brain/Right Brain Theory: Implications for Developmental Math Instruction.

ERIC Educational Resources Information Center

Kitchens, Anita N.; And Others

1991-01-01

Perhaps the most dramatic failure in postsecondary education has been in the teaching of mathematical skills. The different functions of the right and left hemispheres of the brain require different approaches to education. Due to their emphasis on language and verbal processing, schools have failed to give adequate stimulation to the right side…

Children's Mental Health: The Changing Interface between Primary and Specialty Care. Reprint.

ERIC Educational Resources Information Center

Steinberg, A. G.; Gadomski, A.; Wilson, M. D.

The landscape for children's mental health services has changed dramatically due to the confluence of several factors. The emergence of managed care has influenced access to as well as the scope of primary care practice. Evidence-based medicine is steadily emerging and driving practice guideline development. In the rapidly changing and…

The Chicago Project: An Alternative Resettlement Approach.

ERIC Educational Resources Information Center

Refugee Policy Group, Washington, DC.

This document reports on a model refugee resettlement project implemented in Chicago by the United States Catholic Conference. The project was initiated to document the incorrectness of the claim that the current dramatic reduction in U.S. refugee admissions is necessary due to the purported high cost of resettlement. The project served all…

Astrocytic Activation Generates De Novo Neuronal Potentiation and Memory Enhancement.

PubMed

Adamsky, Adar; Kol, Adi; Kreisel, Tirzah; Doron, Adi; Ozeri-Engelhard, Nofar; Melcer, Talia; Refaeli, Ron; Horn, Henrike; Regev, Limor; Groysman, Maya; London, Michael; Goshen, Inbal

2018-05-18

Astrocytes respond to neuronal activity and were shown to be necessary for plasticity and memory. To test whether astrocytic activity is also sufficient to generate synaptic potentiation and enhance memory, we expressed the Gq-coupled receptor hM3Dq in CA1 astrocytes, allowing their activation by a designer drug. We discovered that astrocytic activation is not only necessary for synaptic plasticity, but also sufficient to induce NMDA-dependent de novo long-term potentiation in the hippocampus that persisted after astrocytic activation ceased. In vivo, astrocytic activation enhanced memory allocation; i.e., it increased neuronal activity in a task-specific way only when coupled with learning, but not in home-caged mice. Furthermore, astrocytic activation using either a chemogenetic or an optogenetic tool during acquisition resulted in memory recall enhancement on the following day. Conversely, directly increasing neuronal activity resulted in dramatic memory impairment. Our findings that astrocytes induce plasticity and enhance memory may have important clinical implications for cognitive augmentation treatments. Copyright © 2018 Elsevier Inc. All rights reserved.

The enhanced stability and biodegradation of dispersed crude oil droplets by Xanthan Gum as an additive of chemical dispersant.

PubMed

Wang, Aiqin; Li, Yiming; Yang, Xiaolong; Bao, Mutai; Cheng, Hua

2017-05-15

It is necessary for chemical dispersant to disperse oil effectively and maintain the stability of oil droplets. In this work, Xanthan Gum (XG) was used as an environmentally friendly additive in oil dispersant formulation to enhance the stability and biodegradation of dispersed crude oil droplets. When XG was used together with chemical dispersant 9500A, the dispersion effectiveness of crude oil in artificial sea water (ASW) and the oil droplet stability were both greatly enhanced. In the presence of XG, lower concentration of 9500A was needed to achieve the effective dispersion and stabilization. In addition to the enhancement of dispersion and stabilization, it was found that the biodegradation rate of crude oil by bacteria was dramatically enhanced when a mixture of 9500A and XG was used as a dispersant. Because of the low environmental impact of XG, this would be a potential way to formulate the dispersant with lower toxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enhanced osteoporotic bone regeneration by strontium-substituted calcium silicate bioactive ceramics.

PubMed

Lin, Kaili; Xia, Lunguo; Li, Haiyan; Jiang, Xinquan; Pan, Haobo; Xu, Yuanjin; Lu, William W; Zhang, Zhiyuan; Chang, Jiang

2013-12-01

The regeneration capacity of the osteoporotic bones is generally lower than that of the normal bones. Current methods of bone defect treatment for osteoporosis are not always satisfactory. Recent studies have shown that the silicate based biomaterials can stimulate osteogenesis and angiogenesis due to the silicon (Si) ions released from the materials, and enhance bone regeneration in vivo. Other studies showed that strontium (Sr) plays a distinct role on inhibiting bone resorption. Based on the hypothesis that the combination of Si and Sr may have synergetic effects on osteoporotic bone regeneration, the porous Sr-substituted calcium silicate (SrCS) ceramic scaffolds combining the functions of Sr and Si elements were developed with the goals to promote osteoporotic bone defect repair. The effects of the ionic extract from SrCS on osteogenic differentiation of bone marrow mesenchymal stem cells derived from ovariectomized rats (rBMSCs-OVX), angiogenic differentiation of human umbilical vein endothelial cells (HUVECs) were investigated. The in vitro results showed that Sr and Si ions released from SrCS enhanced cell viability, alkaline phosphatase (ALP) activity, and mRNA expression levels of osteoblast-related genes of rBMSCs-OVX and expression of vascular endothelial growth factor (VEGF) without addition of extra osteogenic and angiogenic reagents. The activation in extracellular signal-related kinases (ERK) and p38 signaling pathways were observed in rBMSCs-OVX cultured in the extract of SrCS, and these effects could be blocked by ERK inhibitor PD98059, and P38 inhibitor SB203580, respectively. Furthermore, the ionic extract of SrCS stimulated HUVECs proliferation, differentiation and angiogenesis process. The in vivo experiments revealed that SrCS dramatically stimulated bone regeneration and angiogenesis in a critical sized OVX calvarial defect model, and the enhanced bone regeneration might be attributed to the modulation of osteogenic differentiation of endogenous mesenchymal stem cells (MSCs) and the inhibition of osteoclastogenesis, accompanying with the promotion of the angiogenic activity of endothelial cells (ECs). Copyright © 2013 Elsevier Ltd. All rights reserved.

The topical application of low-temperature argon plasma enhances the anti-inflammatory effect of Jaun-ointment on DNCB-induced NC/Nga mice.

PubMed

Choi, Jeong-Hae; Song, Yeon-Suk; Lee, Hae-June; Kim, Gyoo-Cheon; Hong, Jin-Woo

2017-06-27

Jaun-ointment (JO), also known as Shiunko in Japan, is one of the most popular medicinal formulae used in Korean traditional medicine for the external treatment of skin wound and inflammatory skin conditions. Since JO is composed of crude mixture of two herbal extracts (radix of Lithospermum erythrorhizon Siebold & Zucc and Angelica gigas Nakai), those been proved its anti-inflammatory activities in-vitro and in-vivo, JO has been expected as a good alternative treatment option for atopic dermatitis (AD). However, due to the lack of strategies for the penetrating methods of JO's various anti-inflammatory elements into the skin, an effective and safe transdermal drug delivery system needs to be determined. Here, low-temperature argon plasma (LTAP) was adopted as an ancillary partner of topically applied JO in a mice model of AD and the effectiveness was examined. Dorsal skins of NC/Nga mice were challenged with DNCB (2,4-dinitrochlorobenzene) to induce AD. AD-like skin lesions were treated with JO alone, or in combination with LTAP. Inflammatory activity in the skin tissues was evaluated by histological analysis and several molecular biological tests. LTAP enhanced the effect of JO on AD-like skin lesion. Topical application of JO partially inhibited the development of DNCB-induced AD, shown by the moderate reduction of eosinophil homing and pro-inflammatory cytokine level. Combined treatment of JO and LTAP dramatically inhibited AD phenotypes. Interestingly, treatment with JO alone did not affect the activity of nuclear factor (NF)κB/RelA in the skin, but combined treatment of LTAP-JO blocked DCNB-mediated NFκB/RelA activation. LTAP markedly enhanced the anti-inflammatory activity of JO on AD-like skin lesions. The effect of LTAP may be attributed to enhancement of drug penetration and regulation of NFκB activity. Therefore, the combination treatment of JO and LTAP could be a potential strategy for the treatment of AD.

Supporting Marine Corps Enhanced Company Operations: A Quantitative Analysis

DTIC Science & Technology

2010-06-01

by decomposition into simple independent parts. o Agents interact with each other in non-linear ways, and “ adapt ” to their local environment . (p...Center Co Company CoLT Company Landing Team CAS Complex Adaptive Systems CSV Comma-separated Value DO Distributed Operations DODIC Department...SUMMARY The modern irregular warfare environment has dramatically impacted the battle space assignments and mission scope of tactical units that now

Dynamic views of living cell fine structure revealed by birefringence imaging

NASA Astrophysics Data System (ADS)

Oldenbourg, Rudolf

2001-11-01

We have been developing and applying a new type of polarized light microscope, the new Pol-Scope, which dramatically enhances the unique capabilities of the traditional polarizing microscope. In living cells, without applying exogenous dyes or florescent labels, we have studied the dynamic organization of filamentous actin in neuronal growth cones and improved the efficiency of spindle imaging for in-vitro fertilization and enucleation procedures.

Oxotremorine does not enhance acetylcholine release from rat diaphragm preparations.

PubMed Central

Gundersen, C. B.; Jenden, D. J.

1980-01-01

We have reinvestigated the dramatic effect of oxotremorine on acetylcholine release from the rat diaphragm reported by Das, Ganguly & Vedasiromoni (1978), using a rigorous gas chromatographic mass spectrometric/isotope dilution method for identification and measurement of acetylcholine and choline. Oxotremorine (10 microM) causes no significant change in the spontaneous or evoked (1 or 10 Hz) release or in the tissue levels of acetylcholine or choline. PMID:7426831

Point Reward System: A Method of Assessment That Accommodates a Diversity of Student Abilities and Interests and Enhances Learning

ERIC Educational Resources Information Center

Derado, Josip; Garner, Mary L.; Tran, Thu-Hang

2016-01-01

Students' abilities and interests vary dramatically in the college mathematics classroom. How do we teach all of these students effectively? In this paper, we present the Point Reward System (PRS), a new method of assessment that addresses this problem. We designed the PRS with three main goals in mind: to increase the retention rates; to keep all…

Sensitivity enhancement and contrasting information provided by free radicals in oriented-sample NMR of bicelle-reconstituted membrane proteins.

PubMed

Tesch, Deanna M; Nevzorov, Alexander A

2014-02-01

Elucidating structure and topology of membrane proteins (MPs) is essential for unveiling functionality of these important biological constituents. Oriented-sample solid-state NMR (OS-NMR) is capable of providing such information on MPs under nearly physiological conditions. However, two dimensional OS-NMR experiments can take several days to complete due to long longitudinal relaxation times combined with the large number of scans to achieve sufficient signal sensitivity in biological samples. Here, free radicals 5-DOXYL stearic acid, TEMPOL, and CAT-1 were added to uniformly (15)N-labeled Pf1 coat protein reconstituted in DMPC/DHPC bicelles, and their effect on the longitudinal relaxation times (T1Z) was investigated. The dramatically shortened T1Z's allowed for the signal gain per unit time to be used for either: (i) up to a threefold reduction of the total experimental time at 99% magnetization recovery or (ii) obtaining up to 74% signal enhancement between the control and radical samples during constant experimental time at "optimal" relaxation delays. In addition, through OS-NMR and high-field EPR studies, free radicals were able to provide positional constraints in the bicelle system, which provide a description of the location of each residue in Pf1 coat protein within the bicellar membranes. This information can be useful in the determination of oligomerization states and immersion depths of larger membrane proteins. Copyright © 2013 Elsevier Inc. All rights reserved.

Synthesis of β-cyclodextrin hydrogel nanoparticles for improving the solubility of dexibuprofen: characterization and toxicity evaluation.

PubMed

Khalid, Qandeel; Ahmad, Mahmood; Minhas, Muhammad Usman

2017-11-01

This study was aimed to enhance aqueous solubility of dexibuprofen through designing β-cyclodextrin (βCD) hydrogel nanoparticles and to evaluate toxicological potential through acute toxicity studies in rats. Dexibuprofen is a non-steroidal analgesic and anti-inflammatory drug that is one of safest over the counter medications. However, its clinical effectiveness is hampered due to poor aqueous solubility. βCD hydrogel nanoparticles were prepared and characterized by percent yield, drug loading, solubilization efficiency, FTIR, XRD, DSC, FESEM and in-vitro dissolution studies. Acute oral toxicity study was conducted to assess safety of oral administration of prepared βCD hydrogel nanoparticles. βCD hydrogel nanoparticles dramatically enhanced the drug loading and solubilization efficiency of dexibuprofen in aqueous media. FTIR, TGA and DSC studies confirmed the formation of new and a stable nano-polymeric network and interactions of dexibuprofen with these nanoparticles. Resulting nanoparticles were highly porous with 287 nm in size. XRD analysis revealed pronounced reduction in crystalline nature of dexibuprofen within nanoparticles. Release of dexibuprofen in βCD hydrogel nanoparticles was significantly higher compared with dexibuprofen tablet at pH 1.2 and 6.8. In acute toxicity studies, no significant changes in behavioral, physiological, biochemical or histopathologic parameters of animals were observed. The efficient preparation, high solubility, excellent physicochemical characteristics, improved dissolution and non-toxic βCD hydrogel nanoparticles may be a promising approach for oral delivery of lipophilic drugs.

Water-wettable polypropylene fibers by facile surface treatment based on soy proteins.

PubMed

Salas, Carlos; Genzer, Jan; Lucia, Lucian A; Hubbe, Martin A; Rojas, Orlando J

2013-07-24

Modification of the wetting behavior of hydrophobic surfaces is essential in a variety of materials, including textiles and membranes that require control of fluid interactions, adhesion, transport processes, sensing, etc. This investigation examines the enhancement of wettability of an important class of textile materials, viz., polypropylene (PP) fibers, by surface adsorption of different proteins from soybeans, including soy flour, isolate,glycinin, and β-conglycinin. Detailed investigations of soy adsorption from aqueous solution (pH 7.4, 25 °C) on polypropylene thin films is carried out using quartz crystal microbalance (QCM) and surface plasmon resonance (SPR). A significant amount of protein adsorbs onto the PP surfaces primarily due to hydrophobic interactions. We establish that adsorption of a cationic surfactant, dioctadecyldimethylammonium bromide (DODA) onto PP surfaces prior to the protein deposition dramatically enhances its adsorption. The adsorption of proteins from native (PBS buffer, pH 7.4, 25 °C) and denatured conditions (PBS buffer, pH 7.4, 95 °C) onto DODA-treated PP leads to a high coverage of the proteins on the PP surface as confirmed by a significant improvement in water wettability. A shift in the contact angle from 128° to completely wettable surfaces (≈0°) is observed and confirmed by imaging experiments conducted with fluorescence tags. Furthermore, the results from wicking tests indicate that hydrophobic PP nonwovens absorb a significant amount of water after protein treatment, i.e., the PP-modified surfaces become completely hydrophilic.

The impact of high-salt exposure on cardiovascular development in the early chick embryo.

PubMed

Wang, Guang; Zhang, Nuan; Wei, Yi-Fan; Jin, Yi-Mei; Zhang, Shi-Yao; Cheng, Xin; Ma, Zheng-Lai; Zhao, Shu-Zhu; Chen, You-Peng; Chuai, Manli; Hocher, Berthold; Yang, Xuesong

2015-11-01

In this study, we show that high-salt exposure dramatically increases chick mortality during embryo development. As embryonic mortality at early stages mainly results from defects in cardiovascular development, we focused on heart formation and angiogenesis. We found that high-salt exposure enhanced the risk of abnormal heart tube looping and blood congestion in the heart chamber. In the presence of high salt, both ventricular cell proliferation and apoptosis increased. The high osmolarity induced by high salt in the ventricular cardiomyocytes resulted in incomplete differentiation, which might be due to reduced expression of Nkx2.5 and GATA4. Blood vessel density and diameter were suppressed by exposure to high salt in both the yolk sac membrane (YSM) and chorioallantoic membrane models. In addition, high-salt-induced suppression of angiogenesis occurred even at the vasculogenesis stage, as blood island formation was also inhibited by high-salt exposure. At the same time, cell proliferation was repressed and cell apoptosis was enhanced by high-salt exposure in YSM tissue. Moreover, the reduction in expression of HIF2 and FGF2 genes might cause high-salt-suppressed angiogenesis. Interestingly, we show that high-salt exposure causes excess generation of reactive oxygen species (ROS) in the heart and YSM tissues, which could be partially rescued through the addition of antioxidants. In total, our study suggests that excess generation of ROS might play an important role in high-salt-induced defects in heart and angiogenesis. © 2015. Published by The Company of Biologists Ltd.

Halide perovskite solar cells using monocrystalline TiO2 nanorod arrays as electron transport layers: impact of nanorod morphology

NASA Astrophysics Data System (ADS)

Thakur, Ujwal Kumar; Askar, Abdelrahman M.; Kisslinger, Ryan; Wiltshire, Benjamin D.; Kar, Piyush; Shankar, Karthik

2017-07-01

This is the first report of a 17.6% champion efficiency solar cell architecture comprising monocrystalline TiO2 nanorods (TNRs) coupled with perovskite, and formed using facile solution processing without non-routine surface conditioning. Vertically oriented TNR ensembles are desirable as electron transporting layers (ETLs) in halide perovskite solar cells (HPSCs) because of potential advantages such as vectorial electron percolation pathways to balance the longer hole diffusion lengths in certain halide perovskite semiconductors, ease of incorporating nanophotonic enhancements, and optimization between a high contact surface area for charge transfer (good) versus high interfacial recombination (bad). These advantages arise from the tunable morphology of hydrothermally grown rutile TNRs, which is a strong function of the growth conditions. Fluorescence lifetime imaging microscopy of the HPSCs demonstrated a stronger quenching of the perovskite PL when using TNRs as compared to mesoporous/compact TiO2 thin films. Due to increased interfacial contact area between the ETL and perovskite with easier pore filling, charge separation efficiency is dramatically enhanced. Additionally, solid-state impedance spectroscopy results strongly suggested the suppression of interfacial charge recombination between TNRs and perovskite layer, compared to other ETLs. The optimal ETL morphology in this study was found to consist of an array of TNRs ∼300 nm in length and ∼40 nm in width. This work highlights the potential of TNR ETLs to achieve high performance solution-processed HPSCs.

Hybrid boron nitride-natural fiber composites for enhanced thermal conductivity

PubMed Central

Xia, Changlei; Garcia, Andres C.; Shi, Sheldon Q.; Qiu, Ying; Warner, Nathaniel; Wu, Yingji; Cai, Liping; Rizvi, Hussain R.; D’Souza, Nandika A.; Nie, Xu

2016-01-01

Thermal conductivity was dramatically increased after adding natural fiber into hexagonal boron nitride (hBN)/epoxy composites. Although natural fiber does not show high-thermal conductivity itself, this study found that the synergy of natural fiber with hBN could significantly improve thermal conductivity, compared with that solely using hBN. A design of mixtures approach using constant fibers with increasing volume fractions of hBN was examined and compared. The thermal conductivity of the composite containing 43.6% hBN, 26.3% kenaf fiber and 30.1% epoxy reached 6.418 W m−1 K−1, which was 72.3% higher than that (3.600 W m−1 K−1) of the 69.0% hBN and 31.0% epoxy composite. Using the scanning electron microscope (SEM) and micro computed tomography (micro-CT), it was observed that the hBN powders were well distributed and ordered on the fiber surfaces enhancing the ceramic filler’s interconnection, which may be the reason for the increase in thermal conductivity. Additionally, the results from mechanical and dynamic mechanical tests showed that performances dramatically improved after adding kenaf fibers into the hBN/epoxy composite, potentially benefiting the composite’s use as an engineered material. PMID:27703226

Plasmon Geometric Phase and Plasmon Hall Shift

NASA Astrophysics Data System (ADS)

Shi, Li-kun; Song, Justin C. W.

2018-04-01

The collective plasmonic modes of a metal comprise a simple pattern of oscillating charge density that yields enhanced light-matter interaction. Here we unveil that beneath this familiar facade plasmons possess a hidden internal structure that fundamentally alters its dynamics. In particular, we find that metals with nonzero Hall conductivity host plasmons with an intricate current density configuration that sharply departs from that of ordinary zero Hall conductivity metals. This nontrivial internal structure dramatically enriches the dynamics of plasmon propagation, enabling plasmon wave packets to acquire geometric phases as they scatter. At boundaries, these phases accumulate allowing plasmon waves that reflect off to experience a nonreciprocal parallel shift. This plasmon Hall shift, tunable by Hall conductivity as well as plasmon wavelength, displaces the incident and reflected plasmon trajectories and can be readily probed by near-field photonics techniques. Anomalous plasmon geometric phases dramatically enrich the nanophotonics toolbox, and yield radical new means for directing plasmonic beams.

SERS of Individual Nanoparticles on a Mirror: Size Does Matter, but so Does Shape

PubMed Central

2016-01-01

Coupling noble metal nanoparticles by a 1 nm gap to an underlying gold mirror confines light to extremely small volumes, useful for sensing on the nanoscale. Individually measuring 10 000 of such gold nanoparticles of increasing size dramatically shows the different scaling of their optical scattering (far-field) and surface-enhanced Raman emission (SERS, near-field). Linear red-shifts of the coupled plasmon modes are seen with increasing size, matching theory. The total SERS from the few hundred molecules under each nanoparticle dramatically increases with increasing size. This scaling shows that maximum SERS emission is always produced from the largest nanoparticles, irrespective of tuning to any plasmonic resonances. Changes of particle facet with nanoparticle size result in vastly weaker scaling of the near-field SERS, without much modifying the far-field, and allows simple approaches for optimizing practical sensing. PMID:27223478