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1

The Tall Tale Ladies.  

ERIC Educational Resources Information Center

Discusses the value of tall tales for children and focuses on tall tale heroines that have become more prevalent and offer models of strong, resourceful, undaunted women. Includes examples of popular tall tale heroines and offers suggestions for class activities. (LRW)

Zingher, Gary

2001-01-01

2

New Approaches to Target T-ALL  

PubMed Central

Acute lymphoblastic leukemia is the most common malignancy in children. Although it is now curable in 80–90% of cases, patients with T-cell acute lymphoblastic leukemia (T-ALL) experience a higher frequency of induction failure and early relapse. Despite aggressive treatment approaches, including transplantation and new salvage regimens, most children with relapsed T-ALL will not be cured. As such, we are in need of new targeted therapies for the disease. Recent advances in the molecular characterization of T-ALL have uncovered a number of new therapeutic targets. This review will summarize recent advancements in the study of inhibiting the NOTCH1, PI3K–AKT, and Cyclin D3:CDK4/6 pathways as therapeutic strategies for T-ALL. We will focus on pre-clinical studies supporting the testing of small-molecule inhibitors targeting these proteins and the rationale of combination therapies. Moreover, epigenetic approaches to modulate T-ALL are rapidly emerging. Here, we will discuss the data supporting the role of bromodomain and extra-terminal bromodomain inhibitors in human T-ALL.

Roti, Giovanni; Stegmaier, Kimberly

2014-01-01

3

Tall Tower Challenge  

NSDL National Science Digital Library

In this activity, learners explore the design of tall structures such as skyscrapers and telecommunication towers. Learners work in teams to engineer the tallest tower they can build using just straws, pipe cleaners, and paperclips. The tower must be strong enough to support the weight of a golf ball for two minutes.

Ieee

2014-05-22

4

A model of technology strategy development for Iranian nano?composite companies  

Microsoft Academic Search

In recent years, Iran's government has emphasized the development of nanotechnology?based industry, so many Iranian companies have gravitated to this subject, or some new companies have established on nanotechnology fields such as nano?composite products. Technology strategy (TS) is one of the most important aspects of any firm's strategic posture especially in dynamic environments; therefore this research is focused on adjusting

Sepehr Ghazinoory; Mahdieh Farazkish

2010-01-01

5

Adaptive sampling strategies for efficient parameter scans in nano-photonic device simulations  

NASA Astrophysics Data System (ADS)

Rigorous optical simulations are an important tool in optimizing scattering properties of nano-photonic devices and are used, for example, in solar cell optimization. The finite element method (FEM) yields rigorous, timeharmonic, high accuracy solutions of the full 3D vectorial Maxwell's equations1 and furthermore allows for great flexibility and accuracy in the geometrical modeling of these often complex shaped 3D nano-structures. A major drawback of frequency domain methods is the limitation of single frequency evaluations. For example the accurate computation of the short circuit current density of an amorphous silicon/micro-crystalline multi-junction thin film solar cell may require the solution of Maxwell's equations for over a hundred different wavelengths if an equidistant sampling strategy is employed. Also in optical metrology, wavelength scans are frequently used to reconstruct unknown geometrical and material properties of optical systems numerically from measured scatterometric data. In our contribution we present several adaptive numerical integration and sampling routines and study their efficiency in the context of the determination of generation rate profiles of solar cells. We show that these strategies lead to a reduction in the computational effort without loss of accuracy. We discuss the employment of tangential information in a Hermite interpolation scheme to achieve similar accuracy on coarser grids. We explore the usability of these strategies for scatterometry and solar cell simulations.

Hammerschmidt, Martin; Pomplun, Jan; Burger, Sven; Schmidt, Frank

2014-03-01

6

Early T-cell Precursor Acute Lymphoblastic Leukemia (ETP T-ALL)  

PubMed Central

Purpose of review Early T-cell Precursor (ETP) leukemias have been recently recognized as a form of T-cell acute lymphoblastic leukemia (T-ALL) with poor prognosis. The purpose of this review is to outline the most recent advances in the biology, genetics and prognostic significance of this aggressive disease. Recent findings Detailed immunophenotypic analyses have defined ETP T-ALLs as a distinct group of T-cell acute lymphoblastic leukemia (T-ALL) with poor prognosis. Transcriptionally, ETP T-ALLs and early immature T-ALLs, a broader group of tumors characterized by very early arrest in T-cell differentiation, are most related to hematopoietic stem cells and myeloid progenitors. Consistently these leukemias show lower frequencies of prototypical T-ALL lesions such as CDKN2A/B deletions and activating mutations in NOTCH1 and show a higher prevalence of mutations typically associated with the pathogenesis of acute myeloid leukemias (AML). Summary ETP and early immature T-ALLs are characterized by a very early differentiation arrest and show unique genetic and transcriptional features that overlap both with T-ALL and AML. Given the unique biology and poor prognosis associated with the ETP T-ALL group there is an urgent need of new tailored therapeutic strategies for the treatment of this disease.

Haydu, J. Erika; Ferrando, Adolfo A.

2013-01-01

7

Increasing crude tall oil yield  

SciTech Connect

In the kraft pulping process for softwoods and hardwood, tall oil recovery is an important part of making profit. During the past 10 years, crude tall oil (CTO) production in the U.S. and Canada has dropped. Estimated CTO yield from fresh Canadian pine is 36-40 lb/a.d. ton and from Southern U.S. 70-80 lb/a.d. ton, while the average yield of CTO is approximately 40% of available tall oil in pine wood. Besides low yield, many pulp mills fail to achieve a CTO quality that lives up to market expectations. The moisture content of CTO is reported to vary widely (1.5-3.5%), whereas it should not exceed 1.5% for marketable quality. The acid number of CTO varies in the range of 135 to 150, whereas industry standards are 145-150. At present the average sale price of CTO is approximately $150/ton. By upgrading existing plants, the yield can be increased, resulting in additional revenues. Thus, if a batch acidulation plant is replaced by a continuous acidulation plant, the yield will increase by approximately 15-50%. The capital required for installing a continuous system is approximately $1.1-1.5 million for a 500-a.d. ton/day pulp mill, requiring a payback period of approximatley 5-7 years. 7 references.

Gupta, J.

1983-10-01

8

Evidence of unconstrained directional selection for male tallness  

Microsoft Academic Search

There are many reports on a positive relationship between tallness and socioeconomic success, and between tallness and health in the human male. Accordingly, tallness is an explanatory variable in many studies on health or behavior. Recently, a positive correlation of tallness with fitness has been reported. However, whether this fitness advantage is the effect of the socioeconomic success of tall

Ulrich Mueller; Allan Mazur

2001-01-01

9

Safe Emergency Evacuation From Tall Structures  

NASA Technical Reports Server (NTRS)

Emergency egress system allows people to be evacuated quickly from tall structures. New emergency system applicable to rescues from fires in tall hotels and other buildings. System consists of basket on slide wire. Basket descends by gravity on sloped slide wire staked to ground.

Stephan, E. S.

1984-01-01

10

Strategy for nano-catalysis in a fixed-bed system.  

PubMed

For industry applications of nano-catalysts, the main bottlenecks are the low loading per unit support area and the slow flow rate through the support particles. By growing a dense Au nanowire forest on a loose network of glass fibers, continuous-flow catalysis can be achieved with a processing rate about 100 times that of the best literature rate. PMID:24719281

He, Jiating; Ji, Weijie; Yao, Lin; Wang, Yawen; Khezri, Bahareh; Webster, Richard D; Chen, Hongyu

2014-06-01

11

Tall Timbers Research Station: Research Programs  

NSDL National Science Digital Library

The Tall Timbers Research Station works to foster land stewardship through its research, conservation, and education efforts. Located in Tallahassee, Florida, the Tall Timbers Station conducts research in the areas of Fire Ecology, Resource Management, Vertebrate Ecology, Forestry, and Northern Bobwhite Quail studies. The Station's website contains overviews of its five major research programs and offers information regarding research jobs and internships. Tall Timbers also provides downloadable copies of its _Research Notes_ publication, and lists a variety of staff publications (some of which are downloadable). In addition, Tall Timbers features the E.V. Komarek Fire Ecology Database (reported on in the Scout Report for Science & Engineering, January 6, 1999) which contains approximately 15,000 citations, and 6,000 abstracts.

12

Photosynthesis in Tall Fescue 1  

PubMed Central

We previously reported that the net photosynthetic rate of a decaploid genotype (I-16-2) of tall fescue (Festuca arundinacea Schreb.) was 32 to 41 versus 22 milligrams CO2 per square decimeter per hour in a hexaploid genotype (V6-802) (Randall, Nelson, Asay Plant Physiol 59: 38-41). The high rate was later correlated with increases in total ribulose 1,5-bisphosphate carboxylase protein (17%) and activity (27%) (Joseph, Randall, Nelson Plant Physiol 68: 894-898). This report characterizes photosynthesis with respect to light saturation and early products of photosynthesis in an attempt to identify regulatory metabolic site(s) in these two genotypes. Analysis of the early products of photosynthesis indicated that both genotypes fixed CO2 via the Calvin-Benson cycle with phosphoglyceric acid as the initial primary product. Both genotypes had similar 14C-labeled intermediates. Sucrose was the primary sink of 14CO2 assimilation. After 10 min of 14CO2 assimilation with attached leaves, sucrose accounted for 89% (decaploid) and 81% (hexaploid) of the total 14C incorporated. In 10 min, this amounted to 1.3 (decaploid) and 0.8 (hexaploid) ?mol [14C]sucrose formed g fresh weight?1 and reflected the observed differences in photosynthetic rates. There was limited labeling of starch (1%) and fructan (1%). Results of total nonstructural carbohydrates and Pi analysis also demonstrated sucrose was the predominant carbohydrate in fescue leaves. Quantitative differences in sucrose and Pi between the two genotypes may reflect changes in partitioning and this possibility is discussed.

Wong, Joshua H. H.; Randall, Douglas D.; Nelson, Curtis J.

1983-01-01

13

Typhoon effects on super-tall buildings  

NASA Astrophysics Data System (ADS)

Full-scale measurement is considered to be the most reliable method for evaluating wind effects on buildings and structures. This paper presents selected results of wind characteristics and structural responses measured from four super-tall buildings, The Center (350 m high, 79 floors) in Hong Kong, Di Wang Tower (384 m high, 78 floors) in Shenzhen, CITIC Plaza Tower (391 m high, 80 floors) in Guangzhou and Jin Mao Building (421 m high, 88 floors) in Shanghai, during the passages of three typhoons. The field data such as wind speed, wind direction and acceleration responses, etc., were continuously measured from the super-tall buildings during the typhoons. Detailed analysis of the field data was conducted to investigate the characteristics of typhoon-generated wind and wind-induced vibrations of these super-tall buildings under typhoon conditions. The dynamic characteristics of the tall buildings were determined from the field measurements and comparisons with those calculated from the finite element (FE) models of the structures were made. Furthermore, the full-scale measurements were compared with wind tunnel results to evaluate the accuracy of the model test results and the adequacy of the techniques used in the wind tunnel tests. The results presented in this paper are expected to be of considerable interest and of use to researchers and professionals involved in designing super-tall buildings.

Li, Q. S.; Xiao, Y. Q.; Wu, J. R.; Fu, J. Y.; Li, Z. N.

2008-06-01

14

Water Potential Gradient in a Tall Sequoiadendron  

PubMed Central

With an elevator installed in a 90-meter tall Sequoiadendron to collect the samples, xylem pressure potential measurements were made approximately every 15 meters along 60 meters of the tree's height. The measured gradient was about ?0.8 bar per 10 meters of height, i.e., less than the hydrostatic gradient. Correction of the xylem pressure potential data by calibration against a thermocouple psychrometer confirmed this result. Similar gradients are described in the literature in tall conifers at times of low transpiration, although a different sampling technique was used. If the data in the present study and those supporting it are typical, they imply a re-evaluation of either the use of the pressure chamber to estimate water potential or the present theories describing water transport in tall trees.

Tobiessen, Peter; Rundel, Philip W.; Stecker, R. E.

1971-01-01

15

Twisters, Tall Tales, and Science Teaching  

NSDL National Science Digital Library

Legends and tall tales have been part of the American culture for ages. Your students are probably already familiar with the tales of how Pecos Bill fearlessly tamed a ferocious tornado, or Paul Bunyan effortlessly restrained a great river. Such tales have been passed down from generation to generation to explain humanity, the natural world, and scientific phenomena. Harness your students' creative engery with this lesson that incorporates tall tales into the classroom, and follows the 5-E model (Engage, Explore, Explain, Elaborate, and Evaluate) for incorporating constructivism into science teaching.

Wilcox, Dawn R.; Sterling, Donna R.

2006-07-01

16

Asphalt Mixtures Modified with Tall Oil Pitches and Cellulose Fibres.  

National Technical Information Service (NTIS)

Tall oil pitch and fiber-modified asphaltic mixtures were characterized in the work. The tall oil pitches were crude distillation residues of crude tall oil. The cellulose fibers were of a commercial grade and consisted of selected sulphate cellulose and ...

P. Peltonen

1992-01-01

17

Asphalt Mixtures Modified with Tall Oil Pitches and Cellulose Fibres.  

National Technical Information Service (NTIS)

Tall oil pitch and fiber modified asphaltic mixtures were characterized. Details of the materials tested are given. The tall oil pitches were crude distillation residues of crude tall oil. The cellulose fibers were of a commercial grade and consisted of s...

P. Peltonen I. Heikkila

1992-01-01

18

Tall tower or mountain top measurements?  

NASA Astrophysics Data System (ADS)

Resolving the regional transport and distribution of greenhouse gases in the troposphere is a key topic that challenges both modelers and experimentalists. A dense network of measurement stations would be required, in particular including measurements at high elevation to better represent the entire lower troposphere, and not only small-scale local conditions in the near-surface atmosphere. While this can be achieved by tall towers, also mountain top stations (e.g. Schauinsland, Brocken) and other stations at high elevation (e.g., Mouna Loa, Jungfraujoch) are often appropriate, due to their extended concentration footprint. However, especially over complex, mountainous terrain, the transport of atmospheric gases and their spatio-temporal distribution is difficult to predict due to the development of thermally induced local wind patterns and boundary layer processes. Therefore, the main goal of our study is to test to what extend boundary layer processes at the surface and local wind patterns close to the ground at a mountain top site influence the ambient greenhouse gas patterns compared to measurements taken at a similar altitude but at a tall tower site. To this end we use measurements from the Zugerberg mountain top station, located at a pre-Alpine mountain ridge (987 m a.s.l., 4 m above ground) exposed to the prevailing synoptic winds in Switzerland, and compare these measurements with a neighboring tall tower site (Beromünster radio broadcast tower with its top at 1014 m a.s.l., 217 m above local ground level, and ?500 m above the Swiss Plateau). The Beromünster tall tower is located at a distance of only 30 km from the mountain top station as the bird flies, and hence a direct comparison minimizes confounding factors that are not related to the tall tower vs. mountain top position of the measurements. Both stations are part of the CarboCount CH greenhouse gas observation network (http://www.carbocount.ch) initiated for long-term monitoring and modeling of greenhouse gas fluxes at a regional scale in order to achieve a better understanding about CO2 and CH4 fluxes and their response to climate. We will present first direct comparisons of measurements obtained from continuously calibrated laser absorption spectrometers to quantify the atmospheric concentrations of carbon-dioxide and methane, but also from meteorological sensors and turbulence measurements. Data from the sensors at the two stations will be used to address the following question: can a mountain top station provide similar quality of data and spatial representativeness as a tall tower for the investigation of atmospheric patterns of greenhouse gases at diurnal to seasonal scale?

Bamberger, Ines; Eugster, Werner; Oney, Brian; Brunner, Dominik; Leuenberger, Markus; Schanda, Rüdiger; Henne, Stephan; Buchmann, Nina

2014-05-01

19

Tall oil precursors of Douglas-fir  

SciTech Connect

The sapwood and heartwood extractives of Douglas fir and the tall oil in the kraft black liquor were characterized. On pulping, isomerization and conversion of conjugated resin acids to dehydroabietic acid was observed. Recovery of both fatty and resin acids from pulping was lower than predicted from the extractive composition. High contents of sterol esters (about 35%) and a new triterpene alcohol are reported. The lightwood-inducing effect of paraquat was limited.

Foster, D.O.; Zinkle, D.F.; Conner, A.H.

1980-01-01

20

Interactive Design Strategy for a Multi-Functional PAMAM Dendrimer-Based Nano-Therapeutic Using Computational Models and Experimental Analysis  

PubMed Central

Molecular dynamics simulations of nano-therapeutics as a final product and of all intermediates in the process of generating a multi-functional nano-therapeutic based on a poly(amidoamine) (PAMAM) dendrimer were performed along with chemical analyses of each of them. The actual structures of the dendrimers were predicted, based on potentiometric titration, gel permeation chromatography, and NMR. The chemical analyses determined the numbers of functional molecules, based on the actual structure of the dendrimer. Molecular dynamics simulations calculated the configurations of the intermediates and the radial distributions of functional molecules, based on their numbers. This interactive process between the simulation results and the chemical analyses provided a further strategy to design the next reaction steps and to gain insight into the products at each chemical reaction step.

Lee, Inhan; Williams, Christopher R.; Athey, Brian D.; Baker, James R.

2010-01-01

21

Dynamic responses of a tapered tall building to wind loads  

Microsoft Academic Search

Many investigations for mitigating wind-induced excitations of tall buildings have been carried out. The aerodynamic modification of a building shape changing the cross-section with height through tapering, which alters the flow pattern around the building, could reduce wind-induced excitations of tall buildings. The fact that a tapered tall building might spread the vortex-shedding over a broad range of frequencies makes

Young-Moon Kim; Ki-Pyo You

2002-01-01

22

Classic Papillary Thyroid Carcinoma with Tall Cell Features and Tall Cell Variant Have Similar Clinicopathologic Features  

PubMed Central

Background The tall cell variant of papillary thyroid carcinoma (TCVPTC) is more aggressive than classic papillary thyroid carcinoma (PTC), but the percentage of tall cells needed to diagnose TCVPTC remains controversial. In addition, little is known about the clinicopathologic features of classic PTC with tall cell features (TCF). Methods We retrospectively selected and reviewed the clinicopathologic features and presence of the BRAF mutation in 203 cases of classic PTC, 149 cases of classic PTC with TCF, and 95 cases of TCVPTCs, which were defined as PTCs having <10%, 10-50%, and ?50% tall cells, respectively. Results TCVPTCs and classic PTCs with TCF did not vary significantly in clinicopathologic characteristics such as pathologic (p) T stage, extrathyroidal extension, pN stage, lateral lymph node metastasis, or BRAF mutations; however, these features differed significantly in TCVPTCs and classic PTCs with TCF in comparison to classic PTCs. Similar results were obtained in a subanalysis of patients with microcarcinomas (?1.0 cm in size). Conclusions Classic PTCs with TCF showed a similar BRAF mutation rate and clinicopathologic features to TCVPTCs, but more aggressive characteristics than classic PTCs.

Oh, Woo Jin; Lee, Young Sub; Cho, Uiju; Bae, Ja Seong; Lee, Sohee; Kim, Min Hee; Lim, Dong Jun; Park, Gyeong Sin; Lee, Youn Soo

2014-01-01

23

Numerical electromagnetic field analysis of lightning current in tall structures  

Microsoft Academic Search

The Numerical Electromagnetic Code (NEC-2) is applied to the electromagnetic analysis of tall structures hit by lightning. The advantage of the analysis using NEC-2 is that it can accurately compute the current distribution along a conductor system by the method of moments. The waveforms of the lightning currents measured on freestanding tall structures are well reproduced, and the computed waveforms

Yoshihiro Baba; Masaru Ishii

2001-01-01

24

DEVELOPMENT OF SEISMIC FRAGILITY CURVES FOR TALL BUILDINGS  

Microsoft Academic Search

This study focuses on the reliability assessment of tall buildings subjected to earthquake loadings. The vulnerabilities of these tall structures are expressed with the development of fragility curves, which provide the probability of exceeding a prescribed level of damage for a wide range of ground motion intensities. Such fragility curves are extremely important for estimating the overall risk to the

Michael W. Tantala; George Deodatis

25

77 FR 19534 - Special Local Regulations; Savannah Tall Ships Challenge, Savannah River, Savannah, GA  

Federal Register 2010, 2011, 2012, 2013

...1625-AA08 Special Local Regulations; Savannah Tall Ships Challenge, Savannah River, Savannah, GA AGENCY...in Savannah, Georgia during the Savannah Tall Ships Challenge. The Savannah Tall Ships Challenge will take place from Thursday, May...

2012-04-02

26

75 FR 34936 - Safety Zone; Chicago Tall Ships Fireworks, Lake Michigan, Chicago, IL  

Federal Register 2010, 2011, 2012, 2013

...1625-AA00 Safety Zone; Chicago Tall Ships Fireworks, Lake Michigan, Chicago, IL...NPRM) entitled Safety Zone; Chicago Tall Ships Fireworks, Chicago, IL in the Federal...hazards associated with the Chicago Tall Ships Fireworks display. The Captain of...

2010-06-21

27

Insect Feeding Deterrents in Endophyte-Infected Tall Fescue †  

PubMed Central

The presence of an endophytic fungus, Acremonium coenophialum, in tall fescue (Festuca arundinacea) deterred aphid feeding by Rhopalosiphum padi and Schizaphis graminum. Both species of aphid were unable to survive when confined to endophyte-infected tall fescue plants. Feeding deterrents and toxic factors to R. padi and Oncopeltus fasciatus, large milkweed bug, were primarily associated with a methanol extract obtained when endophyte-infected tall fescue seed was serially extracted with hexane, ethyl acetate, and methanol. The concentrations of pyrrolizidine alkaloids were determined to be 30 to 100 times greater in the methanol extract than in the hexane and ethyl acetate extracts.

Johnson, M. C.; Dahlman, D. L.; Siegel, M. R.; Bush, L. P.; Latch, G. C. M.; Potter, D. A.; Varney, D. R.

1985-01-01

28

The evaluation of retrofit measures in a tall residential building  

SciTech Connect

As part of a joint demonstration effort involving the US Department of Energy (DOE), the US Department of Housing and Urban Development (HUD), Boston Edison Company (BECo), and the Chelsea Housing Authority, Oak Ridge National Laboratory (ORNL) participated in the evaluation of energy and demand saving retrofits for a tall residential building located in Boston. The thirteen story all-electric building underwent window, lighting, and control renovations in December, 1992. annual energy consumption was reduced by 15% and peak demand fell by 17%. Hourly should building consumption data were available for the comparison of pre- and post- conditions and for calibration of a DOE-2.1D simulation model. The analysis found the window retrofit accounted for 90% of total energy savings and 95% of average demand savings, due to reductions in both conduction and infiltration. Benefits from lighting retrofits were low in cooling months and negligible in winter months due to the increase in the demand for electric resistance heating which was proportional to the reduction in lighting capacity. Finally, the simulation model verified that heating system controls had not been used as intended, and that the utility rate structure would not allow cost savings from the original control strategy. These results and other interesting lessons learned are presented.

Abraham, M.M.; McLain, H.A.

1995-07-01

29

Tall Shrub Dynamics in Northern Minnesota Aspen and Conifer Forests.  

National Technical Information Service (NTIS)

Tall shrub dynamics were examined in upland stands in northern Minnesota. Mortality rates of shrub stems did not differ among the stands. Shrub stem regeneration did differ among the stands and was related to overstory characteristics, soil moisture, and ...

J. C. Balogh D. F. Grigal

1988-01-01

30

Terrace formation in cropping strips protected by tall wheatgrass barriers  

Microsoft Academic Search

by J.K. Aase and J.L. Pikul, Jr. ABSTRACT Tall wheatgrass barriers have been successfully tested in the northern Great Plains for wind erosion control and plant protection. Our objective was to document the passive forma- tion of hillside terraces occasioned by grass barriers on a variable 2 to 4% west to east slope. Eleven double-row tall wheatgrass (Elytrigia elongata (Host)

J. K. Aase; J. L. Pikul

31

Nano nickel oxide modified non-enzymatic glucose sensors with enhanced sensitivity through an electrochemical process strategy at high potential.  

PubMed

Development of fast and sensitive sensors for glucose determination is important in food industry, clinic diagnostics, biotechnology and many other areas. In these years, considerable attention has been paid to develop non-enzymatic electrodes to solve the disadvantages of the enzyme-modified electrodes, such as instability, high cost, complicated immobilization procedure and critical operating situation et al. Nano nickel oxide (NiO) modified non-enzymatic glucose sensors with enhanced sensitivity were investigated. Potential scanning nano NiO modified carbon paste electrodes up to high potential in alkaline solution greatly increases the amount of redox couple Ni(OH)(2)/NiOOH derived from NiO, and thus improves their electrochemical properties and electrocatalytical performance toward the oxidation of glucose. The non-enzymatic sensors response quickly to glucose and the response time is less than 5s, demonstrating excellent electrocatalytical activity and assay performance. The calibration plot is linear over the wide concentration range of 1-110 ?M with a sensitivity of 43.9 nA/?M and a correlation coefficient of 0.998. The detection limit of the electrode was found to be 0.16 ?M at a signal-to-noise ratio of 3. The proposed non-enzymatic sensors can be used for the assay of glucose in real sample. PMID:21167705

Mu, Ying; Jia, Dongling; He, Yayun; Miao, Yuqing; Wu, Hai-Long

2011-02-15

32

A nano-chip-LC/MSn based strategy for characterization of modified nucleosides using reduced porous graphitic carbon as a stationary phase.  

PubMed

LC/MS analysis of ribonucleosides is traditionally performed by reverse phase chromatography on silica based C18 type stationary phases using MS compatible buffers and methanol or acetonitrile gradients. Due to the hydrophilic and polar nature of nucleosides, down-scaling C18 analytical methods to a two-column nano-flow setup is inherently difficult. We present a nano-chip LC/MS ion-trap strategy for routine characterization of RNA nucleosides in the fmol range. Nucleosides were analyzed in positive ion mode by reverse phase chromatography using a 75 ? × 150 mm, 5 ? particle porous graphitic carbon (PGC) chip with an integrated 9 mm, 160 nL trapping column. Nucleosides were separated using a formic acid/acetonitrile gradient. The method was able to separate isobaric nucleosides as well as nucleosides with isotopic overlap to allow unambiguous MS( n ) identification on a low resolution ion-trap. Synthesis of 5-hydroxycytidine (oh(5)C) was achieved from 5-hydroxyuracil in a novel three-step enzymatic process. When operated in its native state using formic acid/acetonitrile, PGC oxidized oh(5)C to its corresponding glycols and formic acid conjugates. Reduction of the PGC stationary phase was achieved by flushing the chip with 2.5 mM oxalic acid and adding 1 mM oxalic acid to the online solvents. Analyzed under reduced chromatographic conditions oh(5)C was readily identified by its MH(+) m/z 260 and MS(n) fragmentation pattern. This investigation is, to our knowledge, the first instance where oxalic acid has been used as an online reducing agent for LC/MS. The method was subsequently used for complete characterization of nucleosides found in tRNAs using both PGC and C18 chips. PMID:21953107

Giessing, Anders Michael Bernth; Scott, Lincoln Greyson; Kirpekar, Finn

2011-07-01

33

Method for tall oil recovery and apparatus therefor  

SciTech Connect

A system and apparatus are disclosed for removing particles from suspension in a liquid, particularly for removing tall oil soap particles from black liquor. The black liquor flows along a fluid flow path which runs between a source of black liquor and a skimming tank. Two electrodes are disposed one downstream of the other within the fluid flow path. A power supply applies an electrical potential between the electrodes. The downstream electrode is connected to earth ground. It has been found that this earth ground connection provides substantial improvements in the quality and quantity of recovered tall oil soap.

Joyce, E.R.; Smith, W.L.

1982-08-31

34

Fatty and resinic acids extractions from crude tall oil  

SciTech Connect

The separation of fatty and resinic acidic fractions from crude tall-oil soap solutions with n-heptane by the technique of dissociation extraction is discussed. The theory of the overall process is supported by a systematic study developed to cover the high selectivity demonstrated in the differential solubility and the aptness between fatty and diterpenic acids to both liquids phases. To study the main factors affecting those liquid-liquid extraction systems and the amphiphilic behavior of such molecules involved, sodium salts aqueous solutions of crude tall oil and synthetic mixtures as molecular acidic models were used.

Nogueira, J.M.F. [Univ. of Lisbon (Portugal)

1996-11-01

35

75 FR 18451 - Safety and Security Zones; Tall Ships Challenge 2010, Great Lakes; Cleveland, OH; Bay City, MI...  

Federal Register 2010, 2011, 2012, 2013

...Zones; Tall Ships Challenge 2010, Great Lakes; Cleveland, OH; Bay City, MI...around each Tall Ship visiting the Great Lakes during the Tall Ships Challenge...while they operate throughout the Great Lakes. The combination of large...

2010-04-12

36

Transient Response of a Tall Object to Lightning  

Microsoft Academic Search

Abstract—Experimental data showing the transient behavior of tall objects struck by lightning are reviewed. The influence of this transient behavior, illustrated by simple calculations, on measured lightning current and measured remote electromagnetic fields is discussed. The estimated equivalent impedance of the lightning channel at the time of the initial current peak is appreciably higher than the characteristic impedance,of an ordinary

Vladimir A. Rakov

2001-01-01

37

Talking and Writing: Deaf Teenagers Reading "Sarah, Plain and Tall."  

ERIC Educational Resources Information Center

Describes a classroom-based research project that investigated how talking and writing about the novel "Sarah, Plain and Tall" (by Patricia MacLachlan) and rereading parts as a group helped four deaf teenagers build meaning and broaden their understanding of the story. (SR)

Hartman, Maria; Kretschmer, Robert E.

1992-01-01

38

Wind pressures on tapered and set-back tall buildings  

NASA Astrophysics Data System (ADS)

Recent tall buildings tend to have irregular and unconventional shapes as a prevailing but unavoidable trend, which is very effective for suppressing across-wind responses. Suppression of across-wind responses is a major factor in safety and habitability design of tall buildings, and the so-called aerodynamic modification method is comprehensively used. While the effectiveness of aerodynamic modification in reducing wind loads has been widely reported, there have been few detailed investigations of pressure fluctuations. The purpose of the present work is to investigate the spatio-temporal characteristics of pressure fluctuations applied to height-modified tall buildings comprehensively, including differences of vortex formation and shedding mechanism based on the previously reported mechanism of a conventional square tall building. The results show that taper and set-back affect on the bandwidth of power spectra and position of peak frequencies. And through taper and set-back, the height at which the vortex begins to form moves up, and due to the small building dimension, the vortex component formed at that height sheds from the building more frequently before an inverted conical vortex is formed over the whole height.

Kim, Yong Chul; Kanda, Jun

2013-05-01

39

Improving the design of tall buildings after 9\\/11  

Microsoft Academic Search

Purpose – Following the terrorist attack on the New York World Trade Center in 2001, this paper seeks to investigate the design features that would enhance the safety of tall buildings. Design\\/methodology\\/approach – Using a questionnaire, data have been collected via e-mails and by post from architects and civil engineers (AEs) in Singapore. Structured interviews were conducted with public authorities.

Florence Yean Yng Ling; Lay Hong Soh

2005-01-01

40

Wind Shear Characteristics at Central Plains Tall Towers (presentation)  

SciTech Connect

The objectives of this report are: (1) Analyze wind shear characteristics at tall tower sites for diverse areas in the central plains (Texas to North Dakota)--Turbines hub heights are now 70-100 m above ground and Wind measurements at 70-100+ m have been rare. (2) Present conclusions about wind shear characteristics for prime wind energy development regions.

Schwartz, M.; Elliott, D.

2006-06-05

41

13. View looking south on Main Street. The tall building ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. View looking south on Main Street. The tall building in the background on the right is the Metals Bank Building (1906), designed by Cass Gilbert. - Butte Historic District, Bounded by Copper, Arizona, Mercury & Continental Streets, Butte, Silver Bow County, MT

42

Wind Shear Characteristics at Central Plains Tall Towers  

SciTech Connect

The object of this study is to analyze wind shear characteristics at tall tower sites in the Central Plains of the United States. The hub heights of modern turbines used for wind farm projects are now 70 meters (m) to 100 m above ground and some advanced turbines under development for deployment during the second half of this decade are rated at 2-5 megawatts of energy generation with rotor diameters near 100 m and hub heights of 100-120 m. These advanced turbines will take advantage of the higher wind speeds aloft to generate more wind energy. Specific knowledge of important wind shear characteristics near and at turbine hub height is needed to optimize turbine design and wind farm layout. Unfortunately, wind speed shear measurements at heights of 80-120 m were virtually nonexistent a few years ago and are still quite uncommon today. The Central Plains is a prime wind energy development region and knowledge about the wind shear characteristics will reduce uncertainty about the resource and enhance wind farm design. Previous analyses of tall tower data (Schwartz and Elliott, 2005) concentrated on data from specific states. The wind energy community has recognized the need to fill the gap of direct wind speed measurements at levels 70 m and higher above the ground. Programs instituted during the last 5 years at the state level and supported by the U.S. Department of Energy's (DOE) State Energy Program initiative have placed anemometers and vanes at several levels on existing tall (70 m+) communication towers. The Central Plains has a fairly high concentration of tall tower sites. The distribution of tall tower sites varies among the states in the Central Plains, because the tall tower program is new and the available state and federal funding to establish tall towers is variable. Our wind resource assessment group at DOE's National Renewable Energy Laboratory (NREL) has obtained much of these necessary measurement data from both individual state sources and regional organizations. Most of the data are available to the public, though data from one tower in Colorado are proprietary. We have begun to analyze important wind climate parameters, including wind shear from the tall towers. A total of 13 tall towers were used for this study. Eleven of the towers had the highest anemometer level between 100 m and 113 m. Two towers had the highest measurement level between 70 m and 85 m above ground. The distribution of the towers among the states is: two sites in Texas and Oklahoma; six sites in Kansas; and one site each in Colorado, South Dakota, and North Dakota. Figure 1 shows the locations and names of the thirteen towers. The wind resource at these sites can be classified as ranging from good-to-excellent. Eight tall tower sites have Class 3 resource, four sites have Class 4 resource, and one has Class 5 resource at 50 m.

Schwartz, M.; Elliott, D.

2006-01-01

43

Processes of recovering fatty acids and sterols from tall oil pitch  

SciTech Connect

An improved process of enhancing the recovery of fatty acids from tall oil pitch is disclosed. The process includes a hydrolysis step for increasing the free fatty acid available for recovery from tall oil pitch during the distillation process. The hydrolysis step also enables the recovery of sterols where the tall oil pitch is of the type which is rich in sterol esters.

Hughes, R. E.

1985-06-18

44

Winter lightning on Japan sea coast; Lightning striking frequency to tall structures  

Microsoft Academic Search

The nature of lightning striking tall structures on Japan sea coast in winter has been observed with automatically triggered camera and current measurements. The frequency of winter lightning striking tall structures is much higher than that of summer lightning and it increases proportionally to the height of structures. Sometimes lightning strikes simultaneously to multiple tall structures. Statistics of the striking

K. Miyake; T. Suzuki; M. Takashima; M. Takuma; T. Tada

1990-01-01

45

77 FR 16974 - Special Local Regulations; Ocean State Tall Ships Festival 2012, Narragansett Bay, RI  

Federal Register 2010, 2011, 2012, 2013

...Special Local Regulations; Ocean State Tall Ships Festival 2012, Narragansett Bay, RI AGENCY...Rhode Island, for the Ocean State Tall Ships Festival 2012. This action is necessary...Rhode Island, during the Ocean State Tall Ships Festival on July 6-9, 2012. These...

2012-03-23

46

75 FR 23209 - Safety Zone; Chicago Tall Ships Fireworks, Lake Michigan, Chicago, IL  

Federal Register 2010, 2011, 2012, 2013

...1625-AA00 Safety Zone; Chicago Tall Ships Fireworks, Lake Michigan, Chicago, IL...from the hazards associated with the Tall Ships Fireworks. The Captain of the Port, Sector...Michigan, has determined that the Tall Ships Fireworks presents significant risks...

2010-05-03

47

78 FR 38580 - Special Local Regulation; Tall Ships Celebration Bay City, Bay City, MI  

Federal Register 2010, 2011, 2012, 2013

...1625-AA08 Special Local Regulation; Tall Ships Celebration Bay City, Bay City, MI AGENCY...temporary special local regulation for a tall ships parade located in the Captain of the Port...impracticable. The final details for this Tall Ships parade were not known to the Coast...

2013-06-27

48

77 FR 39395 - Special Local Regulations; Ocean State Tall Ships Festival 2012, Narragansett Bay, RI  

Federal Register 2010, 2011, 2012, 2013

...Special Local Regulations; Ocean State Tall Ships Festival 2012, Narragansett Bay, RI AGENCY...Rhode Island, for the Ocean State Tall Ships Festival 2012. DATES: This rule is effective...Special Local Regulations: Ocean State Tall Ships Festival 2012, Narragansett Bay,...

2012-07-03

49

Intake estimation of horses grazing tall fescue (Lolium arundinaceum) or fed tall fescue hay.  

PubMed

Six mature geldings of light horse breeds (557 ± 37 kg) were randomly assigned to a nontoxic endophyte-infected tall fescue hay (n = 3) or pasture treatment (n = 3) in a crossover design with 14-d periods to estimate DMI with alkane markers and to compare DMI of hay and pasture. When fed pasture, horses were housed in stalls from 0700 to 1300 h daily with access to water and then grazed pasture as a group in a single 0.4 ha pasture from 1300 to 0700 h. When fed hay, horses were maintained individually in stalls and given access to hay ad libitum from 1300 to 0700 h. All horses were individually fed 225 g oats twice daily treated with hexatriacontane (C36; external marker) and fecal samples were collected at 0700 and 1900 h on d 10 to 14. Fecal samples were mixed, dried, subsampled, and analyzed for tritriacontane (C33) and hentriacontane (C31) as internal markers and C36 as the external marker using gas chromatography. Estimated hay DMI using either C33 (1.75 kg/100 kg BW) or C31 (1.74 kg/100 kg BW) as internal alkane marker did not differ (P = 0.55) from measured hay DMI (1.70 kg/100 kg BW). Pasture DMI and DM digestibility (DMD) estimated with C31 (2.24 kg/100 kg BW and 53.1 g/100 g DMI) or with C33 (2.34 kg/100 kg BW and 56.2 g/100 g DMI) was greater (P = 0.05) than hay DMI and DMD (1.74 kg/100 kg BW and 44.5 g/100 g DMI). Intake estimated with C33 or C31 did not differ (P = 0.35) during hay or pasture. In conclusion, alkanes can be used to estimate pasture or hay DMI and DMD, and pasture intake exceeded hay intake when offered ad libitum. PMID:24663171

Chavez, S J; Siciliano, P D; Huntington, G B

2014-05-01

50

Forages and pastures symposium: fungal endophytes of tall fescue and perennial ryegrass: pasture friend or foe?  

PubMed

Tall fescue [Lolium arundinaceum (Schreb.) Darbysh. syn. Festuca arundinacea Schreb.] and perennial ryegrass (Lolium perenne L.) are important perennial forage grasses utilized throughout the moderate- to high-rainfall temperate zones of the world. These grasses have coevolved with symbiotic fungal endophytes (Epichloë/Neotyphodium spp.) that can impart bioactive properties and environmental stress tolerance to the grass compared with endophyte-free individuals. These endophytes have proven to be very important in pastoral agriculture in the United States, New Zealand, and Australia, where forage grasses are the principal feed for grazing ruminants. In this review, we describe the biology of these grass-endophyte associations and implications for the livestock industries that are dependent on these forages. Endophyte alkaloid production is put in context with endophyte diversity, and we illustrate how this has facilitated utilization of grasses infected with different endophyte strains that reduce livestock toxicity issues. Utilization of tall fescue and use of perennial ryegrass in the United States, New Zealand, and Australia are compared, and management strategies focused predominantly on the success of endophyte-infected perennial ryegrass in New Zealand and Australia are discussed. In addition, we consider the impact of grass-endophyte associations on the sustainability of pasture ecosystems and their likely response to future changes in climate. PMID:23307839

Young, C A; Hume, D E; McCulley, R L

2013-05-01

51

FHL1C induces apoptosis in notch1-dependent T-ALL cells through an interaction with RBP-J  

PubMed Central

Background Aberrantly activated Notch signaling has been found in more than 50% of patients with T-cell acute lymphoblastic leukemia (T-ALL). Current strategies that employ ?-secretase inhibitors (GSIs) to target Notch activation have not been successful. Many limitations, such as non-Notch specificity, dose-limiting gastrointestinal toxicity and GSI resistance, have prompted an urgent need for more effective Notch signaling inhibitors for T-ALL treatment. Human four-and-a-half LIM domain protein 1C (FHL1C) (KyoT2 in mice) has been demonstrated to suppress Notch activation in vitro, suggesting that FHL1C may be new candidate target in T-ALL therapy. However, the role of FHL1C in T-ALL cells remained unclear. Methods Using RT-PCR, we amplified full-length human FHL1C, and constructed full-length and various truncated forms of FHL1C. Using cell transfection, flow cytometry, transmission electron microscope, real-time RT-PCR, and Western blotting, we found that overexpression of FHL1C induced apoptosis of Jurkat cells. By using a reporter assay and Annexin-V staining, the minimal functional sequence of FHL1C inhibiting RBP-J-mediated Notch transactivation and inducing cell apoptosis was identified. Using real-time PCR and Western blotting, we explored the possible molecular mechanism of FHL1C-induced apoptosis. All data were statistically analyzed with the SPSS version 12.0 software. Results In Jurkat cells derived from a Notch1-associated T-ALL cell line insensitive to GSI treatment, we observed that overexpression of FHL1C, which is down-regulated in T-ALL patients, strongly induced apoptosis. Furthermore, we verified that FHL1C-induced apoptosis depended on the RBP-J-binding motif at the C-terminus of FHL1C. Using various truncated forms of FHL1C, we found that the RBP-J-binding motif of FHL1C had almost the same effect as full-length FHL1C on the induction of apoptosis, suggesting that the minimal functional sequence in the RBP-J-binding motif of FHL1C might be a new drug candidate for T-ALL treatment. We also explored the molecular mechanism of FHL1C overexpression-induced apoptosis, which suppressed downstream target genes such as Hes1 and c-Myc and key signaling pathways such as PI3K/AKT and NF-?B of Notch signaling involved in T-ALL progression. Conclusions Our study has revealed that FHL1C overexpression induces Jurkat cell apoptosis. This finding may provide new insights in designing new Notch inhibitors based on FHL1C to treat T-ALL.

2014-01-01

52

Evolutionary history of tall fescue morphotypes inferred from molecular phylogenetics of the Lolium-Festuca species complex  

PubMed Central

Background The agriculturally important pasture grass tall fescue (Festuca arundinacea Schreb. syn. Lolium arundinaceum (Schreb.) Darbysh.) is an outbreeding allohexaploid, that may be more accurately described as a species complex consisting of three major (Continental, Mediterranean and rhizomatous) morphotypes. Observation of hybrid infertility in some crossing combinations between morphotypes suggests the possibility of independent origins from different diploid progenitors. This study aims to clarify the evolutionary relationships between each tall fescue morphotype through phylogenetic analysis using two low-copy nuclear genes (encoding plastid acetyl-CoA carboxylase [Acc1] and centroradialis [CEN]), the nuclear ribosomal DNA internal transcribed spacer (rDNA ITS) and the chloroplast DNA (cpDNA) genome-located matK gene. Other taxa within the closely related Lolium-Festuca species complex were also included in the study, to increase understanding of evolutionary processes in a taxonomic group characterised by multiple inter-specific hybridisation events. Results Putative homoeologous sequences from both nuclear genes were obtained from each polyploid species and compared to counterparts from 15 diploid taxa. Phylogenetic reconstruction confirmed F. pratensis and F. arundinacea var. glaucescens as probable progenitors to Continental tall fescue, and these species are also likely to be ancestral to the rhizomatous morphotype. However, these two morphotypes are sufficiently distinct to be located in separate clades based on the ITS-derived data set. All four of the generated data sets suggest independent evolution of the Mediterranean and Continental morphotypes, with minimal affinity between cognate sequence haplotypes. No obvious candidate progenitor species for Mediterranean tall fescues were identified, and only two putative sub-genome-specific haplotypes were identified for this morphotype. Conclusions This study describes the first phylogenetic analysis of the Festuca genus to include representatives of each tall fescue morphotype, and to use low copy nuclear gene-derived sequences to identify putative progenitors of the polyploid species. The demonstration of distinct tall fescue lineages has implications for both taxonomy and molecular breeding strategies, and may facilitate the generation of morphotype and/or sub-genome-specific molecular markers.

2010-01-01

53

Nano Waterproofing  

NSDL National Science Digital Library

This lesson focuses on how nanotechnology has impacted the design and engineering of many everyday items from paint to fabrics. Learners explore the hydrophobic effect and how similar properties can be introduced by reengineering products at the nano level. Learners work in teams to develop a waterproof material and compare their results with nano waterproof materials developed recently by engineers and scientists.

Ieee

2013-07-30

54

Fog deposition in tall tussock grassland, South Island, New Zealand  

NASA Astrophysics Data System (ADS)

Hill cloud microphysics was examined with a forward scattering spectrometer probe over tall tussock grassland at Swampy Summit near Dunedin, New Zealand. In a 4-month period, cloud water drop diameter spectra were obtained for 17 cloud-ground intersection events that varied from 1 to 61 h in duration. Rain fell in most events. Easterly conditions made up 60% of the events and had a median cloud drop diameter of 13.9 ?m and 0.14 g m-3 liquid water content. For southwest winds, median drop diameter and liquid water content were significantly smaller at 9.8 ?m and 0.05 g m-3. Aerodynamic conductance for momentum transfer, measured with a three-dimensional sonic anemometer, varied linearly with wind speed (R2=0.7) between 50 and 70 mm s-1 for wind speeds from 4 to 9 m s-1. Combining this relation with the cloud liquid water content measurements, cloud water deposition rates were estimated onto the 0.8-m-tall tussock canopy of one-sided leaf area index=3. These estimates were in the range 0.02-0.26 mm h-1 with a median of 0.05 mm h-1 which is the same as the median rate derived from the water balance of a large weighing lysimeter containing eight tussock plants. However, the water balance included a number of small quantities with determination of evaporation and rainfall being particularly difficult. Consequently, the lowest cloud water deposition rates for the water balance were sometimes negative. Nevertheless, even the maximum estimated rates incorporated into an annual calculation suggest cloud water deposition is unlikely to be a significant component of the water balance of a tall tussock grassland catchment. In the uplands of southern New Zealand, changing land use from tall tussock to pastoral agriculture with short vegetation is unlikely to alter streamflows via the cloud water deposition process.

Cameron, C. S.; Murray, D. L.; Fahey, B. D.; Jackson, R. M.; Kelliher, F. M.; Fisher, G. W.

1997-06-01

55

Process for tertiary oil recovery using tall oil pitch  

SciTech Connect

Compositions and process employing same for enhancing the recovery of residual acid crudes, particularly heavy crudes, by injecting a composition comprising caustic in an amount sufficient to maintain a pH of at least about 11, preferably at least about 13, and a small but effective amount of a multivalent cation for inhibiting alkaline silica dissolution with the reservoir. Preferably a tall oil pitch soap is included and particularly for the heavy crudes a polymeric mobility control agent.

Radke, C. J.

1985-07-02

56

Probabilistic Performance Criteria for Tall Buildings Subjected to Wind Loads  

Microsoft Academic Search

Database-assisted design (DAD) uses time histories of pressures simultaneously measured in the wind tunnel at a large number of pressure taps to calculate structural response to wind. DAD, in combination with reliability-based procedures, allows the estimation of load factors in a more site- and structure-specific manner. In this paper we outline the reliability-based, database-assisted design procedure for tall, flexible buildings.

Sofia M. C. Dini; Mihai Iancovici; William Fritz; Michael A. Riley; Emil Simiu

57

Plasmon nano-optical tweezers  

Microsoft Academic Search

Conventional optical tweezers, formed at the diffraction-limited focus of a laser beam, have become a powerful and flexible tool for manipulating micrometre-sized objects. Extending optical trapping down to the nanometre scale would open unprecedented opportunities in many fields of science, where such nano-optical tweezers would allow the ultra-accurate positioning of single nano-objects. Among the possible strategies, the ability of metallic

Mathieu L. Juan; Maurizio Righini; Romain Quidant

2011-01-01

58

Understanding Nano  

NSDL National Science Digital Library

Nanotechnology can be a complicated topic. The Understanding Nano website is dedicated to providing clear and concise explanations of nanotechnology applications along with information on companies working in each area.

2013-07-05

59

Arabidopsis DREB1A \\/ CBF3 bestowed transgenic tall fescue increased tolerance to drought stress  

Microsoft Academic Search

In order to improve drought tolerance of tall fescue (Festuca arundinacea Schreb.), an important perennial cool-season grass, we introduced Arabidopsis DREB1A\\/CBF3 driven by the inducible rd29A promoter into tall fescue mediated by Agrobacterium tumefaciens strains AGL1. PCR and Southern blot analysis confirmed that DREB1A\\/CBF3 gene had been integrated into the genome of tall fescue. AtDREB1A gene was stably inherited and

Junsheng Zhao; Wei Ren; Daying Zhi; Lin Wang; Guangmin Xia

2007-01-01

60

Interference effects on wind-induced coupled motion of a tall building  

Microsoft Academic Search

Interference effects from neighbouring buildings on wind-induced coupled translational–torsional motion of tall buildings have been investigated through a series of wind tunnel aeroelastic model tests. Interference effects on the CAARC standard tall building by an 8:1:1 tall interfering building both upstream and downstream were investigated. The results indicated a significant increase in responses at the critical wind speed where the

S Thepmongkorn; G. S Wood; K. C. S Kwok

2002-01-01

61

Winter lightning on Japan sea coast; Lightning striking frequency to tall structures  

SciTech Connect

The nature of lightning striking tall structures on Japan sea coast in winter has been observed with automatically triggered camera and current measurements. The frequency of winter lightning striking tall structures is much higher than that of summer lightning and it increases proportionally to the height of structures. Sometimes lightning strikes simultaneously to multiple tall structures. Statistics of the striking frequency, striking angle and the leader length of the lightning discharge are presented.

Miyake, K.; Suzuki, T. (Central Research Inst. of Electric Power Industry, Tokyo (Japan)); Takashima, M. (Hokuriku Electric Power Co., Inc., Toyama (Japan)); Takuma, M. (Tokyo Electric Power Co., Chiyoda, Tokyo (JP)); Tada, T. (Sankosha Co., Sagamihara, Kanagawa (JP))

1990-07-01

62

Severe B cell hyperplasia and autoimmune disease in TALL1 transgenic mice  

Microsoft Academic Search

TALL-1\\/Blys\\/BAFF is a member of the tumor necrosis factor (TNF) ligand superfamily that is functionally involved in B cell proliferation. Here, we describe B cell hyperplasia and autoimmune lupus-like changes in transgenic mice expressing TALL-1 under the control of a -actin promoter. The TALL-1 transgenic mice showed severe enlargement of spleen, lymph nodes, and Peyer's patches because of an increased

Sanjay D. Khare; Ildiko Sarosi; Xing-Zhong Xia; Susan McCabe; Kent Miner; Irina Solovyev; Nessa Hawkins; Michael Kelley; David Chang; Gwyneth van; Larry Ross; John Delaney; Ling Wang; David Lacey; William J. Boyle; Hailing Hsu

2000-01-01

63

Alleviation of heat damage to photosystem II by nitric oxide in tall fescue.  

PubMed

Nitric oxide (NO) has been found to mediate plant responses to heat stress. The objective of this study was to investigate the protective role of NO in the recovery process of photosystem II (PSII) in tall fescue (Festuca arundinacea) against heat stress. Treatment of tall fescue leaves with NO donor sodium nitroprusside significantly improved the overall behavior of PSII probed by the chlorophyll a fluorescence transients, while the inhibition of NO accumulation by 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (PTIO, a NO scavenger) plus N (G)-nitro-L-arginine-methyl ester (L-NAME, NO synthase inhibitor) dramatically disrupted the operation of PSII. Specifically, under heat stress, the exogenous NO reduced the initial fluorescence (F 0), increased the maximal quantum yield (F V/F M), and disappeared the K-step of 0.3 ms. By the analysis of the JIP-test, the exogenous NO improved the quantum yield of the electron transport flux from Q A to Q B (ET0/ABS), and decreased the trapped excitation flux per reaction center (RC) (TR0/RC), electron transport flux per RC (ET0/RC), and electron flux reducing end electron acceptors per RC (RE0/RC). In addition, the exogenous NO reduced the content of H2O2, O 2 (•-) , and malondialdehyde and electrolyte leakage of tall fescue leaves. These data suggest that exogenous NO could protect plants, increase the amount of activated RC and improve the electron transport from oxygen evolving complex to D1 protein. Moreover, quantitative RT-PCR revealed that, in the presence of hydrogen peroxide, NO induced the gene expression of psbA, psbB, and psbC, which encode proteins belonging to subunits of PSII core reaction center (Psb) complex. These findings indicate that, as an important strategy to protect plants against heat stress, NO could improve the recovery process of PSII by the up regulation of the transcriptions of genes encoding PSII core proteins. PMID:23832593

Chen, Ke; Chen, Liang; Fan, Jibiao; Fu, Jinmin

2013-09-01

64

Strategis  

NSDL National Science Digital Library

Strategis is a web site developed by Industry Canada to provide business information resources to Canadian businesses. Resources available include a searchable database of Canadian companies, business information for each sector, a list of business support services, and a guide to business laws and regulation. The International Business Information Network offers information about business opportunities abroad; Trade Data Online provides Canadian and US trade data. A collection of research publications by Industry Canada and monthly economic indicators on the economy are additional economic resources found at this site. Users can view this site in French or English.

1998-01-01

65

Taking on the tall poles of autonomous robot navigation  

NASA Astrophysics Data System (ADS)

The Holy Grail of autonomous ground robotics has been to make ground vehicles that behave like humans. Over the years, as a community, we have realized the difficulty of this task, and we have back pedaled from the initial Holy Grail and have constrained and narrowed the domains of operation in order to get robotic systems fielded. This has lead to phrases such as "operation in structured environments" and "open-and-rolling terrain" in the context of autonomous robot navigation. Unfortunately, constraining the problem in this way has only put off the inevitable, i.e., solving the myriad of difficult robotics problems that we identified as long ago as the 1980's on the Autonomous Land Vehicle Project and in most cases are still facing today. These "Tall Poles" have included but are not limited to navigation through complex terrain geometry, navigation through thick vegetation, the detection of geometry-less obstacles such as negative obstacles and thin obstacles, the ability to deal with diverse and dynamic environmental conditions, the ability to function in dynamic and cluttered environments alongside other humans, and any combination of the above. This paper is an overview of the progress we have made at Autonomous Systems over the last three years in trying to knock down some of the tall poles remaining in the field of autonomous ground robotics.

Rosenblum, Mark; Rajagopalan, Venkat; Steinbis, John; Haddon, John; Cannon, Paul

2011-05-01

66

Lightning initiation from a tall structure in the Basque Country  

NASA Astrophysics Data System (ADS)

Lightning detection in the Spanish Basque Country is performed using the LF TOA, VHF interferometer and the VLF lightning detection technologies in which two independent networks are based, providing a better detection quality due to the combination of these different techniques. Total lightning activity related to the tall structure of the weather radar operated by the Basque Meteorology Agency (Euskalmet) is presented. The tall structure is a 50 m tower located on the top of Kapildui Mountain (at about 1169.48 m ASL). Remarkable electrical activity associated to this place has been witnessed in the last two years. Two particular flashes during November 30th 2009 caused damage to the weather radar. Two different lightning detection networks detected five and six cloud-to-ground strokes, respectively. Only nine VHF sources were detected in the first flash without any VLF detection classified as intracloud. But for the second flash non VHF source was detected and two detections were reported by the VLF system. In both cases some intracloud detections were reported before cloud-to-ground strokes and some others during the flash. This paper presents the study of a winter episode with a special impact in the tower, the research carried out for characterizing the lightning events and the measures taken in order to achieve a better protection mechanism for the radar site.

López, J.; Montanyà, J.; Maruri, M.; De la Vega, D.; Aranda, J. A.; Gaztelumendi, S.

2012-11-01

67

Development of Efficient Models of Corona Discharges Around Tall Structures  

NASA Astrophysics Data System (ADS)

This work concerns with numerical modeling of glow corona and sreamer corona discharges that occur near tall ground structures under thunderstorm conditions. Glow corona can occur when ambient electric field reaches modest values on the order of 0.2 kV/cm and when the electric field near sharp points of ground structure rises above a geometry dependent critical field required for ionization of air. Air is continuously ionized in a small region close to the surface of the structure and ions diffuse out into the surrounding air forming a corona. A downward leader approaching from a thundercloud causes a further increase in the electric field at the ground level. If the electric field rises to the point where it can support formation of streamers in air surrounding the tall structure, a streamer corona flash, or series of streamer corona flashes can be formed significantly affecting the space charge configuration formed by the preceding glow corona. The streamer corona can heat the surrounding air enough to form a self-propagating thermalized leader that is launched upward from the tall structure. This leader travels upward towards the thundercloud and connects with the downward approaching leader thus causing a lightning flash. Accurate time-dependent modeling of charge configuration created by the glow and streamer corona discharges around tall structure is an important component for understanding of the sequence of events leading to lightning attachment to the tall structure. The present work builds on principal modeling ideas developed previously in [Aleksandrov et al., J. Phys. D: Appl. Phys., 38, 1225, 2005; Bazelyan et al., Plasma Sources Sci. Technol., 17, 024015, 2008; Kowalski, E. J., Honors Thesis, Penn State Univ., University Park, PA, May 2008; Tucker and Pasko, NSF EE REU Penn State Annual Res. J., 10, 13, 2012]. The non-stationary glow and streamer coronas are modeled in spherical geometry up to the point of initiation of the upward leader. The model uses an implicit numerical scheme for time integration and employs effective non-uniform grid system allowing very accurate description of non-stationary coronas emitted by sharp points with sub-millimeter dimensions and expanding hundreds of meters in surrounding air. In the talk we will present principal components of the model and its performance under different time dynamics of the applied electric field closely resembling scenarios under thunderstorm conditions, including, in particular, extended periods of time (tens of seconds) when only glow corona is produced, followed by a fast rise in the field (tens of microseconds) describing approach of the downward leader. We will also present comparisons of the numerical model results on time dependent corona radius and current with an analytical corona theory summarized recently by Bazelyan et al. [2008].

Tucker, J.; Pasko, V. P.

2012-12-01

68

Tall fescue EST-SSR markers with transferability across several grass species  

Microsoft Academic Search

Tall fescue (Festuca arundinacea Schreb.) is a major cool season forage and turf grass in the temperate regions of the world. It is also a close relative of other important forage and turf grasses, including meadow fescue and the cultivated ryegrass species. Until now, no SSR markers have been developed from the tall fescue genome. We designed 157 EST-SSR primer

Malay C. Saha; M. A. Rouf Mian; Imad Eujayl; John C. Zwonitzer; Liangjiang Wang; Gregory D. May

2004-01-01

69

A hybrid RANS and kinematic simulation of wind load effects on full-scale tall buildings  

Microsoft Academic Search

Up till recent years, predicting wind loads on full-scale tall buildings using Large Eddy Simulation (LES) is still impractical due to a prohibitively large amount of meshes required, especially in the vicinity of the near-wall layers of the turbulent flow. A hybrid approach is proposed for solving pressure fluctuations of wind flows around tall buildings based on the Reynolds Averaged

M. F. Huang; I. W. H Lau; C. M. Chan; K. C. S. Kwok; G. Li

2011-01-01

70

Growth and magnesium uptake of tall fescue lines at high and low potassium levels  

Microsoft Academic Search

Five tall fescue (Festuca arundinacea Schreb.) clonal lines with diverse root and xylem diameters were grown in nutrient solutions with magnesium (Mg) concentrations of 42, 125 and 250 ?M and potassium K concentrations of 133 and 333 ?M. Leaf Mg concentrations increased with increasing Mg rates at both low and high K concentrations. The tall fescue line with the largest

J. H. Edwards; J. F. Pedersen

1986-01-01

71

Recent Results From the NOAA\\/ESRL GMD Tall Tower Network  

Microsoft Academic Search

We will present a summary of new results from NOAA Earth System Research Laboratory`s Tall Tower greenhouse gas monitoring network. The tower network is operated by the Global Monitoring Division, which also maintains the global Cooperative Air Sampling network and a network of aircraft profiling sites over North America. Tall tower CO2 mixing ratio measurements are sensitive to upwind fluxes

A. E. Andrews; P. P. Tans; W. Peters; A. Hirsch; C. Sweeney; G. Petron; J. Kofler; C. Zhao; K. Masarie; S. C. Wofsy; D. M. Matross; P. Mahadevan; M. Longo; C. Gerbig; J. C. Lin

2006-01-01

72

Seasonal variations in nutrient and carbohydrate levels of tall fescue cultivars in Japan  

Microsoft Academic Search

Quality (color and density) of tall fescue (Festuca arundinacea Schreb.) as a turfgrass is reduced during both the winter and summer in Japan. Seasonal variations in nutrient and carbohydrate levels of six cultivars of tall fescue were measured to determine if these changes are related to the reduction in the turf quality. There were significant differences among the cultivars in

Khorshid Razmjoo; Takayuki Imada; Junko Sugiura; Seiji Kaneko

1997-01-01

73

Comparison of endogenous gibberellins and response to applied gibberellin of some dwarf and tall wheat cultivars  

Microsoft Academic Search

A number of dwarf wheat cultivars of the Norin 10 type were compared with several tall forms. Applied gibberellic acid markedly stimulated the growth of seedlings of the tall cultivars but not the growth of dwarf seedlings. Several other gibberellins were also inactive when tested with one dwarf cultivar. De-embryonated grains of all cultivars formed a-amylase in response to gibberellic

Margaret Radley

1970-01-01

74

Tall Poppies: Bullying Behaviors Faced by Australian High-Performance School-Age Athletes  

ERIC Educational Resources Information Center

Little is known about Australian high-performance school-age athletes' experiences as victims of the tall poppy syndrome. Tall poppies are successful individuals bullied by those who are less successful in order to "normalize them." Nineteen current or previous national or international high-performance school-age athletes were…

O'Neill, Maureen; Calder, Angela; Allen, Bill

2014-01-01

75

Analysis of tall fescue ESTs representing different abiotic stresses, tissue types and developmental stages  

Microsoft Academic Search

BACKGROUND: Tall fescue (Festuca arundinacea Schreb) is a major cool season forage and turf grass species grown in the temperate regions of the world. In this paper we report the generation of a tall fescue expressed sequence tag (EST) database developed from nine cDNA libraries representing tissues from different plant organs, developmental stages, and abiotic stress factors. The results of

MA Rouf Mian; Yan Zhang; Zeng-Yu Wang; Ji-Yi Zhang; Xiaofei Cheng; Lei Chen; Konstantin Chekhovskiy; Xinbin Dai; Chunhong Mao; Foo Cheung; Xuechun Zhao; Ji He; Angela D Scott; Christopher D Town; Gregory D May

2008-01-01

76

A Qualitative Perspective of Tall College Women's Intrinsic Dynamics Relating to Height  

ERIC Educational Resources Information Center

We conducted in-depth interviews with 24 tall college females for the present phenomenological, qualitative research study. As tall females in our study described the impact of height on their self-perceptions, two over-arching key height-related outcomes emerged, each of which contained sub-components. First, participants described themselves as…

Firmin, Michael W.; Hoffman, Sarah J.; Firmin, Ruth L.; Lee, Alisha D.; Vorobyov, Yelana

2013-01-01

77

Nano Letters  

NSDL National Science Digital Library

An electronic version of this journal from the American Chemical Society is available for free through June 30, 2001. Nano Letters is ACS's newest journal. It deals with "physical, chemical, and biological phenomena, processes and applications of structures within the nanoscale range."

78

40 CFR 721.9672 - Amides, tall-oil fatty, N-[2-[2-hydroxyethyl)amino]ethyl], reaction products with sulfur dioxide...  

Code of Federal Regulations, 2010 CFR

...products with sulfur dioxide; fatty acids, tall-oil, reaction products...1-piperazineethanamine and sulfur dioxide; fatty acids, tall-oil reaction products...products with sulfur dioxide; fatty acids, tall-oil, reaction...

2010-07-01

79

40 CFR 721.9672 - Amides, tall-oil fatty, N-[2-[2-hydroxyethyl)amino]ethyl], reaction products with sulfur dioxide...  

Code of Federal Regulations, 2010 CFR

...products with sulfur dioxide; fatty acids, tall-oil, reaction products...1-piperazineethanamine and sulfur dioxide; fatty acids, tall-oil reaction products...products with sulfur dioxide; fatty acids, tall-oil, reaction...

2009-07-01

80

77 FR 47624 - Tall Bear Group, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request...  

Federal Register 2010, 2011, 2012, 2013

...Regulatory Commission [Docket No. ER12-2374-000] Tall Bear Group, LLC; Supplemental Notice That Initial Market- Based...supplemental notice in the above-referenced proceeding, of Tall Bear Group, LLC's application for market-based rate...

2012-08-09

81

Clinical and molecular characterization of early T-cell precursor leukemia: a high-risk subgroup in adult T-ALL with a high frequency of FLT3 mutations  

PubMed Central

A subgroup of pediatric acute T-lymphoblastic leukemia (T-ALL) was characterized by a gene expression profile comparable to that of early T-cell precursors (ETPs) with a highly unfavorable outcome. We have investigated clinical and molecular characteristics of the ETP-ALL subgroup in adult T-ALL. As ETP-ALL represents a subgroup of early T-ALL we particularly focused on this cohort and identified 178 adult patients enrolled in the German Acute Lymphoblastic Leukemia Multicenter studies (05/93–07/03). Of these, 32% (57/178) were classified as ETP-ALL based on their characteristic immunophenotype. The outcome of adults with ETP-ALL was poor with an overall survival of only 35% at 10 years, comparable to the inferior outcome of early T-ALL with 38%. The molecular characterization of adult ETP-ALL revealed distinct alterations with overexpression of stem cell-related genes (BAALC, IGFBP7, MN1, WT1). Interestingly, we found a low rate of NOTCH1 mutations and no FBXW7 mutations in adult ETP-ALL. In contrast, FLT3 mutations, rare in the overall cohort of T-ALL, were very frequent and nearly exclusively found in ETP-ALL characterized by a specific immunophenotype. These molecular characteristics provide biologic insights and implications with respect to innovative treatment strategies (for example, tyrosine kinase inhibitors) for this high-risk subgroup of adult ETP-ALL.

Neumann, M; Heesch, S; Gokbuget, N; Schwartz, S; Schlee, C; Benlasfer, O; Farhadi-Sartangi, N; Thibaut, J; Burmeister, T; Hoelzer, D; Hofmann, W-K; Thiel, E; Baldus, C D

2012-01-01

82

40 CFR 721.10188 - Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Fatty acids, tall-oil, reaction products...Substances § 721.10188 Fatty acids, tall-oil, reaction products...identified generically as fatty acids, tall-oil, reaction...Releaseâ variables are the number of kilograms released of...

2013-07-01

83

40 CFR 721.10189 - Fatty acids, tall-oil, reaction products with (butoxymethyl) oxirane formaldehyde-phenol polymer...  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Fatty acids, tall-oil, reaction products...Substances § 721.10189 Fatty acids, tall-oil, reaction...identified generically as fatty acids, tall-oil, reaction...Releaseâ variables are the number of kilograms released of...

2013-07-01

84

40 CFR 454.40 - Applicability; description of manufacture of tall oil rosin, pitch and fatty acids subcategory.  

Code of Federal Regulations, 2010 CFR

...manufacture of tall oil rosin, pitch and fatty acids subcategory. 454.40 Section...CATEGORY Tall Oil Rosin, Pitch and Fatty Acids Subcategory § 454.40 Applicability...manufacture of tall oil rosin, pitch and fatty acids subcategory. The...

2010-07-01

85

40 CFR 454.40 - Applicability; description of manufacture of tall oil rosin, pitch and fatty acids subcategory.  

Code of Federal Regulations, 2010 CFR

...manufacture of tall oil rosin, pitch and fatty acids subcategory. 454.40 Section...CATEGORY Tall Oil Rosin, Pitch and Fatty Acids Subcategory § 454.40 Applicability...manufacture of tall oil rosin, pitch and fatty acids subcategory. The...

2009-01-01

86

Nano-storage wires.  

PubMed

We report the development of "nano-storage wires" (NSWs), which can store chemical species and release them at a desired moment via external electrical stimuli. Here, using the electrodeposition process through an anodized aluminum oxide template, we fabricated multisegmented nanowires composed of a polypyrrole segment containing adenosine triphosphate (ATP) molecules, a ferromagnetic nickel segment, and a conductive gold segment. Upon the application of a negative bias voltage, the NSWs released ATP molecules for the control of motor protein activities. Furthermore, NSWs can be printed onto various substrates including flexible or three-dimensional structured substrates by direct writing or magnetic manipulation strategies to build versatile chemical storage devices. Since our strategy provides a means to store and release chemical species in a controlled manner, it should open up various applications such as drug delivery systems and biochips for the controlled release of chemicals. PMID:23859333

Lee, Dong Jun; Kim, Eunji; Kim, Daesan; Park, Juhun; Hong, Seunghun

2013-08-27

87

Principles of Nano-Optics  

NASA Astrophysics Data System (ADS)

Nano-optics is the study of optical phenomena and techniques on the nanometer scale, that is, near or beyond the diffraction limit of light. It is an emerging field of study, motivated by the rapid advance of nanoscience and nanotechnology which require adequate tools and strategies for fabrication, manipulation and characterization at this scale. In Principles of Nano-Optics the authors provide a comprehensive overview of the theoretical and experimental concepts necessary to understand and work in nano-optics. With a very broad perspective, they cover optical phenomena relevant to the nanoscale across diverse areas ranging from quantum optics to biophysics, introducing and extensively describing all of the significant methods. This is the first textbook specifically on nano-optics. Written for graduate students who want to enter the field, it includes problem sets to reinforce and extend the discussion. It is also a valuable reference for researchers and course teachers. The first nano-optics textbook, it gives a bottom-up description of optical phenomena and techniques encountered in the rapidly expanding fields of nanoscience and nanotechnology Each chapter contains several exercises and problems with hints Numerous high quality illustrations and real-life examples

Novotny, Lukas; Hecht, Bert

2006-06-01

88

Changing the term "breast tumor resembling the tall cell variant of papillary thyroid carcinoma" to "tall cell variant of papillary breast carcinoma".  

PubMed

Papillary lesions of the breast continue to be a diagnostic challenge because of the wide morphologic spectrum that may be encountered in these lesions. A rare entity termed "breast tumor resembling the tall cell variant of papillary thyroid carcinoma" is considered to be a subtype of papillary carcinoma of the breast. It is characterized by distinct morphologic features, setting it apart from typical papillary carcinoma of the breast. Its resemblance to papillary thyroid carcinoma in conjunction with the established terminology may cause confusion, resulting in unnecessary ancillary studies to exclude the association of this lesion with papillary thyroid carcinoma. As immunohistochemical and molecular studies have shown no evidence to support any association between this entity and papillary thyroid carcinoma, we propose to change the current terminology of "breast tumor resembling the tall cell variant of papillary thyroid carcinoma" to the term "tall cell variant of papillary breast carcinoma." PMID:22313838

Masood, Shahla; Davis, Cindy; Kubik, Melanie J

2012-03-01

89

Extreme Tall Stature in a Japanese Boy with a 48,XXYY Karyotype  

PubMed Central

We report an 18-yr-old Japanese boy with a 48,XXYY karyotype and extreme tall stature (194 cm). A GnRH test at 12.5 yr of age showed hypergonadotropism (LH, 4.2 ? 72.2 mIU/mL; FSH, 28.9 ? 61.7 mIU/mL), and an hCG test at 15.5 yr of age revealed a normal testosterone response (1.67 ? 4.08 ng/mL). The tall stature is remarkable, because the mean adult height of Caucasian 48,XXYY patients is 181 cm. Although the underlying factors for the tall stature are unknown, this report indicates an association of the 48,XXYY karyotype with marked tall stature.

Katsushima, Yuriko; Katsushima, Fumio; Katsushima, Noriko

2008-01-01

90

78 FR 44014 - Safety Zones; Tall Ship Safety Zones; War of 1812 Bicentennial Commemoration, Great Lakes  

Federal Register 2010, 2011, 2012, 2013

...1812 Bicentennial Commemoration, Great Lakes AGENCY: Coast Guard, DHS. ACTION...participating in the Tall Ships Challenge Great Lakes 2013 and the War of 1812 Bicentennial...commercial traffic throughout the Great Lakes. DATES: This rule will be...

2013-07-23

91

78 FR 25410 - Safety Zone; Tall Ship Safety Zones; War of 1812 Bicentennial Commemoration, Great Lakes  

Federal Register 2010, 2011, 2012, 2013

...1812 Bicentennial Commemoration, Great Lakes AGENCY: Coast Guard, DHS. ACTION...participating in the Tall Ships Challenge Great Lakes 2013 and the War of 1812 Bicentennial...commercial traffic throughout the Great Lakes. DATES: Comments and...

2013-05-01

92

Amended safety assessment of tall oil acid, sodium tallate, potassium tallate, and ammonium tallate.  

PubMed

Tall oil acid is a mixture of oleic and linoleic acids (fatty acids) and rosin acids derived from tall oil, a by-product of pulp from resinous woods, used in cosmetic products as a surfactant at concentrations up to 8%. Ammonium, potassium, and sodium salts also are listed as cosmetic ingredients. In addition to the studies summarized in this report, extensive toxicity, genotoxicity, and carcinogenicity studies in animals are available for oleic, lauric, palmitic, myristic, and stearic fatty acids as published earlier by the Cosmetic Ingredient Review (CIR). These data may be extrapolated to tall oil acid and its salts. There are no reports of current uses or use concentration data for ammonium tallate, nor are use concentration data available for the other salts. The CIR Expert Panel found tall oil acid, ammonium tallate, potassium tallate, and sodium tallate to be safe cosmetic ingredients in the given practices of use and concentration. PMID:20086195

Robinson, Valerie; Bergfeld, Wilma F; Belsito, Donald V; Klaassen, Curtis D; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Alan Andersen, F

2009-01-01

93

Torsional Excitation and Interference Effects of Tall Buildings with Structural Eccentricity.  

National Technical Information Service (NTIS)

This report describes an experimental investigation in wind tunnel of torsional excitation of a tall square building with structural eccentricity and torsional interference effects on the eccentric building response from neighboring buildings of different...

W. J. Zhang K. C. S. Kwok Y. L. Xu

1992-01-01

94

Antitumor activity of a human cytotoxic T-cell line (TALL-104) in brain tumor xenografts.  

PubMed

Malignant glioma in adults and primitive neuroectodermal tumors/medulloblastomas in children are the most common malignant primary brain tumors that either respond poorly to current treatment or tend to recur. Adoptive therapy with TALL-104 cells-an IL-2-dependent, major histocompatibility complex nonrestricted, cytotoxic T-cell line-has demonstrated significant antitumor activity against a broad range of implanted or spontaneously arising tumors. This study investigates distribution of systemically and locally administered TALL-104 cells and their efficacy in effecting survival of a rat model of human brain tumor. In vitro, TALL-104 cells showed significant cytotoxic activity when added to human glioblastoma cell lines U-87 MG, U-251 MG, and A1690; the medulloblastoma cell lines DAOY, D283 Med, and D341 Med; and the epidermoid cancer cell line A431. In brain tumor-bearing rats, the amount of fluorescent dye-labeled TALL-104 cells in brain increased after they were given by intracarotid injection as compared with i.v. cell administration. However, TALL-104 cells rapidly decreased to low levels within 1 h after intracarotid injection. This finding suggests that TALL-104 cells given systemically may not invade brain or tumor tissues, but rather may remain in the vascular system, making this approach less efficient for brain tumor treatment. In a model of athymic rats engrafted with human A431 carcinoma brain tumor, repetitive local administration of TALL-104 cells directly into the tumor bed resulted in a significant increase in survival time compared with control animals. Therefore, local therapy with TALL-104 cells may be a novel and highly effective treatment approach for malignant brain tumors. PMID:11303619

Geoerger, B; Tang, C B; Cesano, A; Visonneau, S; Marwaha, S; Judy, K D; Sutton, L N; Santoli, D; Phillips, P C

2000-04-01

95

caNanoLab  

Cancer.gov

QUICK LINKS NCI caNanoLab Wiki NCI CBIIT Home NCL Home NCL CSN Home NCI Nano Alliance Home NCI Home EXTERNAL  Disclaimer NBI NIOSH NIL InterNano nanoHUB ICON SAFENANO HOME PROTOCOLS SAMPLES PUBLICATIONS HELP GLOSSARY LOGIN Search Protocols Help

96

caNanoLab  

Cancer.gov

QUICK LINKS NCI caNanoLab Wiki NCI CBIIT Home NCL Home NCL CSN Home NCI Nano Alliance Home NCI Home EXTERNAL  Disclaimer NBI NIOSH NIL InterNano nanoHUB ICON SAFENANO HOME PROTOCOLS SAMPLES PUBLICATIONS HELP GLOSSARY LOGIN Basic Sample Search Advanced

97

caNanoLab  

Cancer.gov

QUICK LINKS NCI caNanoLab Wiki NCI CBIIT Home NCL Home NCL CSN Home NCI Nano Alliance Home NCI Home EXTERNAL  Disclaimer NBI NIOSH NIL InterNano nanoHUB ICON SAFENANO HOME PROTOCOLS SAMPLES PUBLICATIONS HELP GLOSSARY LOGIN Search Publications Help

98

caNanoLab  

Cancer.gov

QUICK LINKS NCI caNanoLab Wiki NCI CBIIT Home NCL Home NCL CSN Home NCI Nano Alliance Home NCI Home EXTERNAL  Disclaimer NBI NIOSH NIL InterNano nanoHUB ICON SAFENANO HOME PROTOCOLS SAMPLES PUBLICATIONS HELP GLOSSARY LOGIN Unexpected Exception:

99

caNanoLab  

Cancer.gov

QUICK LINKS NCI caNanoLab Wiki NCI CBIIT Home NCL Home NCL CSN Home NCI Nano Alliance Home NCI Home EXTERNAL  Disclaimer NBI NIOSH NIL InterNano nanoHUB ICON SAFENANO HOME PROTOCOLS SAMPLES PUBLICATIONS HELP GLOSSARY LOGIN Advanced Sample Search Basic

100

Induction of tall fescue toxicosis in heat-stressed cattle and its alleviation with thiamin.  

PubMed

Livestock grazing endophyte (Acremonium coenophialum)-infected tall fescue (Festuca arundinacea Schreb. cv. Kentucky 31) at high ambient temperatures may suffer from fescue toxicosis. Adult Angus cows (Bos taurus) were fed 0 to 1 kg/d of 70% infected tall fescue seed containing about 4.4 g of loline alkaloids in factorial combination with thiamin at 0 or 1 g/d. Cows assigned to the zero level of tall fescue seed received a supplement of equivalent energy and protein. Ingestive behavior was measured at 1330 to 1430 EDT during two 4-d periods in two consecutive weeks in August on alfalfa (Medicago sativa L.) pastures using a tethered grazing system. Alfalfa intake per measured grazing session of cows given tall fescue seed declined linearly (P less than .01) as air temperatures during grazing increased above 25 degrees C, largely because of shorter grazing meals. Thiamin increased alfalfa intake per measured grazing session by extending grazing time. Alkaloids in ingested endophyte-infected tall fescue induce thiamin deficiencies in cattle that result in symptoms of tall fescue toxicosis. PMID:2061231

Dougherty, C T; Lauriault, L M; Bradley, N W; Gay, N; Cornelius, P L

1991-03-01

101

Nano-technology and nano-toxicology  

PubMed Central

Rapid developments in nano-technology are likely to confer significant benefits on mankind. But, as with perhaps all new technologies, these benefits are likely to be accompanied by risks, perhaps by new risks. Nano-toxicology is developing in parallel with nano-technology and seeks to define the hazards and risks associated with nano-materials: only when risks have been identified they can be controlled. This article discusses the reasons for concern about the potential effects on health of exposure to nano-materials and relates these to the evidence of the effects on health of the ambient aerosol. A number of hypotheses are proposed and the dangers of adopting unsubstantiated hypotheses are stressed. Nano-toxicology presents many challenges and will need substantial financial support if it is to develop at a rate sufficient to cope with developments in nano-technology.

Maynard, Robert L.

2012-01-01

102

Nano Magazine  

NSDL National Science Digital Library

Billed as "the magazine for small science," Nano Magazine has an impressive online presence. Published in Britain, the magazine covers all aspects of nanotechnology and its various applications. Along the top of the homepage, visitors will find a "Hot News" area that scrolls important news developments in the field. Visitors can move on to look through the "Latest Issue" area, which contains interviews with experts in nanotechnology, its role in environmental sustainability, and editorial pieces. For professionals working in this area, the site also has a thorough listing of industry and scholarly events and a list of accredited degree programs for those seeking additional formal training. Finally, visitors can browse through the magazine archive, where past thematic issues include "Nanomedicine" and "Cars of the Future".

103

Increased responsiveness to intravenous lipopolysaccharide challenge in steers grazing endophyte-infected tall fescue compared with steers grazing endophyte-free tall fescue  

Microsoft Academic Search

Fescue toxicosis in cattle occurs as a result of consump- tion of ergot alkaloids in endophyte-infected (E+, Neotyphodium coenophialum) tall fescue (Festuca arundinacea). The condition is characterized by pyrexia, decreased weight gains, rough hair coats, and decreased calving rates. The objective of this experiment was to investigate whether steers grazing E+ fescue have altered host response to lipopolysaccharide (endotoxin, LPS)

N M Filipov; F N Thompson; J A Stuedemann; T H Elsasser; S Kahl; R P Sharma; L H Stanker; C K Smith

1999-01-01

104

Genotypic and Chemotypic Diversity of Neotyphodium Endophytes in Tall Fescue from Greece  

PubMed Central

Epichloid endophytes provide protection from a variety of biotic and abiotic stresses for cool-season grasses, including tall fescue. A collection of 85 tall fescue lines from 15 locations in Greece, including both Continental and Mediterranean germplasm, was screened for the presence of native endophytes. A total of 37 endophyte-infected lines from 10 locations were identified, and the endophytes were classified into five distinct groups (G1 to G5) based on physical characteristics such as colony morphology, growth rate, and conidial morphology. These classifications were supported by phylogenetic analyses of housekeeping genes tefA and tubB, and the endophytes were further categorized as Neotyphodium coenophialum isolates (G1, G4, and G5) or Neotyphodium sp. FaTG-2 (Festuca arundinacea taxonomic group 2 isolates (G2 and G3). Analyses of the tall fescue matK chloroplast genes indicated a population-wide, host-specific association between N. coenophialum and Continental tall fescue and between FaTG-2 and Mediterranean tall fescue that was also reflected by differences in colonization of host tillers by the native endophytes. Genotypic analyses of alkaloid gene loci combined with chemotypic (chemical phenotype) profiles provided insight into the genetic basis of chemotype diversity. Variation in alkaloid gene content, specifically the presence and absence of genes, and copy number of gene clusters explained the alkaloid diversity observed in the endophyte-infected tall fescue, with one exception. The results from this study provide insight into endophyte germplasm diversity present in living tall fescue populations.

Takach, Johanna E.; Mittal, Shipra; Swoboda, Ginger A.; Bright, Sherrita K.; Trammell, Michael A.; Hopkins, Andrew A.

2012-01-01

105

Wood-derived olefins by steam cracking of hydrodeoxygenated tall oils.  

PubMed

Tall oil fractions obtained from Norwegian spruce pulping were hydrodeoxygenated (HDO) at pilot scale using a commercial NiMo hydrotreating catalyst. Comprehensive two dimensional gas chromatography (GC×GC) showed that HDO of both tall oil fatty acids (TOFA) and distilled tall oil (DTO) produced highly paraffinic hydrocarbon liquids. The hydrotreated fractions also contained fatty acid methyl esters and norabietane and norabietatriene isomers. Steam cracking of HDO-TOFA in a pilot plant revealed that high light olefin yields can be obtained, with 35.4 wt.% of ethene and 18.2 wt.% of propene at a coil outlet pressure (COP) of 1.7 bara, a dilution of 0.45 kg(steam)/kg(HDO-TOFA) and a coil outlet temperature (COT) of 820 °C. A pilot plant coking experiment indicated that cracking of HDO-TOFA at a COT of 850 °C results in limited fouling in the reactor. Co-cracking of HDO tall oil fractions with a typical fossil-based naphtha showed improved selectivity to desired light olefins, further demonstrating the potential of large scale olefin production from hydrotreated tall oil fractions in conventional crackers. PMID:23079410

Pyl, Steven P; Dijkmans, Thomas; Antonykutty, Jinto M; Reyniers, Marie-Françoise; Harlin, Ali; Van Geem, Kevin M; Marin, Guy B

2012-12-01

106

Diterpene resin acids: Major active principles in tall oil against Variegated cutworm,Peridroma saucia (Lepidoptera: Noctuidae).  

PubMed

Tall oil, a by-product of the kraft process for pulping softwood, has been shown to have insecticidal properties. In the present study, the active principles in tall oil against the variegated cutworm,Peridroma saucia Hübner, were investigated. GC-MS analysis showed that abietic, dehydroabietic, and isopimaric acids were major resin acid components of crude tall oil and depitched tall oil. When crude tall oil samples of differing resin acid composition were incorporated into artificial diet at a concentration of 2.0% fresh weight, they suppressed larval growth by 45-60% compared to controls. This suppression was significantly (P?0.05) correlated with the equivalent contents of abietic, dehydroabietic, isopimaric, and total resin acids. These results were also evident from a diet choice test, showing that the second-instar larvae obviously selected diets with low levels of resin acids when different diets were randomly arranged in a Petri dish. Bioassays with pure resin acids (abietic, dehydroabietic, and isopimaric acids) demonstrated that all individual chemicals have similar bioactivity against this insect. Comparison of the bioactivities of depitched tall oil and an equivalent mixture of pure resin acids in thePeridroma chronic growth bioassay indicated that pure resin acids and depitched tall oil share a common mode of action to this insect. This study confirms that resin acids are major active principles in tall oil against the variegated cutworm, but other chemicals likely also contribute to the bioactivity of tall oil. PMID:24249127

Xie, Y; Isman, M B; Feng, Y; Wong, A

1993-06-01

107

Metal-enhanced fluorescence of nano-core-shell structure used for sensitive detection of prion protein with a dual-aptamer strategy.  

PubMed

Metal-enhanced fluorescence (MEF) as a newly recognized technology is widespread throughout biological research. The use of fluorophore-metal interactions is recognized to be able to alleviate some of fluorophore photophysical constraints, favorably increase both the fluorophore emission intensity and photostability. In this contribution, we developed a novel metal-enhanced fluorescence (MEF) and dual-aptamer-based strategy to achieve the prion detection in solution and intracellular protein imaging simultaneously, which shows high promise for nanostructure-based biosensing. In the presence of prion protein, core-shell Ag@SiO2, which are functionalized covalently by single stranded aptamer (Apt1) of prions and Cyanine 3 (Cy3) decorated the other aptamer (Apt2) were coupled together by the specific interaction between prions and the anti-prion aptamers in solution. By adjusting shell thickness of the pariticles, a dual-aptamer strategy combined MEF can be realized by the excitation and/or emission rates of Cy3. It was found that the enhanced fluorescence intensities followed a linear relationship in the range of 0.05-0.30 nM, which is successfully applied to the detection of PrP in mice brain homogenates. PMID:23830445

Hu, Ping Ping; Zheng, Lin Ling; Zhan, Lei; Li, Jing Yun; Zhen, Shu Jun; Liu, Hui; Luo, Ling Fei; Xiao, Geng Fu; Huang, Cheng Zhi

2013-07-17

108

Effects of solids content, settling temperature, and liquor source on tall oil solubilities  

SciTech Connect

Tall oil soap solubility in black liquors obtained from cooking pine and sweet gum, and in mixture of these liquors, was studied. As expected, solids content had a significant effect on the amount of soap remaining in settled liquors obtained from pine. Concentrating these liquors to about 30% solids reduced the soap concentration to approximately 0.8% of solids. Increasing the temperature at which the liquors were settled also increased residual tall oil soap content. Although mass balance calculations on mixtures of black liquors obtained from pine and gum show that the percentage recovery (solids basis) varies little with the inclusion of 12 to 50% hardwood black liquor, absolute recovery is increased with increased proportions of hardwood liquor. This is the result of decreased soap solubility with increased proportions of hardwood liquor. No discernable effect was observed on the proportion and composition of the acids and neutrals of the dissolved tall oil with respect to the solids content of the liquors.

Rousseau, R.W.; Kassebi, A.; Zinkel, D.F.

1984-01-01

109

Nano Scavenger Hunt  

NSDL National Science Digital Library

This is an activity (located on page 3 of PDF) about identifying nanoscale objects and phenomena in today's world. Learners will break into groups and conduct a "NanoBlitz Challenge," spending a set amount of time on a scavenger hunt for all things nano, both natural and man-made, in the world around them. They will then assemble a chart of their findings and discuss. Also relates to linked video, DragonflyTV Nano: Where's Nano?

Twin Cities Public Television, Inc.

2008-01-01

110

Does Fungal Endophyte Infection Improve Tall Fescue's Growth Response to Fire and Water Limitation?  

PubMed Central

Invasive species may owe some of their success in competing and co-existing with native species to microbial symbioses they are capable of forming. Tall fescue is a cool-season, non-native, invasive grass capable of co-existing with native warm-season grasses in North American grasslands that frequently experience fire, drought, and cold winters, conditions to which the native species should be better-adapted than tall fescue. We hypothesized that tall fescue’s ability to form a symbiosis with Neotyphodium coenophialum, an aboveground fungal endophyte, may enhance its environmental stress tolerance and persistence in these environments. We used a greenhouse experiment to examine the effects of endophyte infection (E+ vs. E?), prescribed fire (1 burn vs. 2 burn vs. unburned control), and watering regime (dry vs. wet) on tall fescue growth. We assessed treatment effects for growth rates and the following response variables: total tiller length, number of tillers recruited during the experiment, number of reproductive tillers, tiller biomass, root biomass, and total biomass. Water regime significantly affected all response variables, with less growth and lower growth rates observed under the dry water regime compared to the wet. The burn treatments significantly affected total tiller length, number of reproductive tillers, total tiller biomass, and total biomass, but treatment differences were not consistent across parameters. Overall, fire seemed to enhance growth. Endophyte status significantly affected total tiller length and tiller biomass, but the effect was opposite what we predicted (E?>E+). The results from our experiment indicated that tall fescue was relatively tolerant of fire, even when combined with dry conditions, and that the fungal endophyte symbiosis was not important in governing this ecological ability. The persistence of tall fescue in native grassland ecosystems may be linked to other endophyte-conferred abilities not measured here (e.g., herbivory release) or may not be related to this plant-microbial symbiosis.

Hall, Sarah L.; McCulley, Rebecca L.; Barney, Robert J.; Phillips, Timothy D.

2014-01-01

111

An Exceptionally Simple Strategy for DNA-Functionalized Up-conversion Nanoparticles as Biocompatible Agents for Nano-Assembly, DNA Delivery and Imaging  

PubMed Central

Lanthanide-doped upconversion nanoparticles (UCNPs) have shown promise in biomedical applications. However, as the UCNPs are normally capped with hydrophobic ligands, it remains challenging to prepare biocompatible UCNPs with specific molecular recognition capabilities. We herein report an exceptionally simple strategy to prepare uniform DNA-modified upconversion nanoparticles (DNA-UCNPs) as versatile bioprobes. The approach can directly convert as-prepared hydrophobic UCNPs into water-soluble DNA-UCNPs without any chemical modification of UCNPs or oligonucleotides. Furthermore, DNA molecules on the DNA-UCNPs retain their biorecognition ability, allowing programmable assembly of hybrid nanostructures. More importantly, we show that these DNA-UCNPs are capable of crossing cell membranes without the need of transfection agents, and their use as agents for bioimaging and DNA delivery are also demonstrated. Finally, DNA aptamer-conjugated UCNPs can be readily used for targeted imaging of cancer cells.

Li, Le-Le; Wu, Peiwen; Hwang, Kevin; Lu, Yi

2013-01-01

112

Effect of tall stacks on the long range transport of air pollutants  

SciTech Connect

Tall stacks are an effective means of reducing ground level concentrations near to sources, though they do not reduce the total burden of pollution in the atmosphere. In recent discussions of the acid rain question it has often been assumed that the use of tall stacks has had an adverse effect by allowing material to spread more widely in the atmosphere. The purpose of this study is to examine the effect of height of SO/sub 2/ emission releases on total sulfur deposition using a simple calculation.

Fisher, B.E.A.

1986-04-01

113

Integrating bermudagrass into tall fescue-based pasture systems for stocker cattle.  

PubMed

The daily BW gain of stocker steers grazing tall fescue [Lolium arundinaceum (Schreb.) S.J. Darbysh. = Schedonorus arundinaceus (Schreb.) Dumort.]-based pastures typically declines during summer. To avoid these declines, in part to mitigate the effects of tall fescue toxicosis, it is commonly advised to move cattle to warm-season forage during this period. A 3-yr (2006, 2007, and 2008) grazing study was conducted to evaluate the effect of replacing 25% of the area of a tall fescue/clover (81% endophyte-infected) pasture system with "Ozark" bermudagrass [Cynodon dactylon (L.) Pers.] overseeded with clover (Trifolium spp.) to provide summer grazing for stocker steers (TF+BERM). The TF+BERM treatment was compared with a grazing system in which tall fescue/clover (TF) pastures were the only type of forage available for grazing. Our objective was to determine if replacement of 25% of the land area in a fescue system with bermudagrass would increase annual beef production compared with a system based solely on tall fescue. The study was conducted at the Southwest Research and Education Center of the University of Missouri near Mt. Vernon. Each treatment was rotationally stocked with 5 steers (248 ± 19.3 kg) on 1.7 ha. Fertilizer applications were applied at rates recommended for each respective forage species. Total forage production, BW gain per hectare, and season-long ADG of steers was greater (P < 0.06) for TF+BERM than for TF in 2006, but none of these measures differed (P > 0.19) in 2007 or 2008. In vitro true digestibility of pastures was greater (P = 0.01) for TF (84.4%, SEM = 0.64%) compared with TF+BERM (80.6%, SEM = 0.79%), even in summer. The decreased in vitro true digestibility of the bermudagrass pastures likely negated any benefit that animals in TF+BERM had in avoiding the ergot-like alkaloids associated with endophyte-infected tall fescue. Renovating 25% of the pasture system to bermudagrass provided some benefit to the system in years when summertime precipitation was limited (2006) but provided no value in wetter years (2007 and 2008). Although renovating endophyte-infected tall fescue pastures to a warm-season forage is a widely used practice to mitigate tall fescue toxicosis, the benefits of this practice are limited if forage quality of the warm season component is poor. PMID:21856893

Kallenbach, R L; Crawford, R J; Massie, M D; Kerley, M S; Bailey, N J

2012-01-01

114

Meiosis and fertility of F 1 hybrids between hexaploid bread wheat and decaploid tall wheatgrass ( Thinopyrum ponticum )  

Microsoft Academic Search

As the first step in the transfer of barely yellow dwarf virus resistance and salt tolerance from decaploid tall wheatgrass (Thinopyrum ponticum) into hexaploid bread wheat (Triticum aestivum L.), octoploid intergeneric hybrids (2n = 8x = 56) were synthesized by crossing the tall wheatgrass cultivar ‘Alkar’ with wheat cvs. ‘Fukuhokomugi’ (‘Fuko’) and ‘Chinese Spring’. (‘Fuko’ x ‘Alkar’) F1 hybrids were

P. P. Jauhar

1995-01-01

115

Shade tolerance: when growing tall is not an option.  

PubMed

Two different plant strategies exist to deal with shade: shade avoidance and shade tolerance. All shade-exposed plants optimize photosynthesis to adapt to the decrease in light quality and quantity. When shaded, most species in open habitats express the shade-avoidance syndrome, a growth response to escape shade. Shade-tolerant species from forest understories cannot outgrow surrounding trees and adopt a tolerance response. Unlike shade avoidance, virtually nothing is known about regulation of shade tolerance. In this opinion article, we discuss potential modes of molecular regulation to adopt a shade-tolerance rather than a shade-avoidance strategy. We argue that molecular approaches using model and non-model species should help identify the molecular pathways that underpin shade tolerance, thus providing knowledge for further crop improvement. PMID:23084466

Gommers, Charlotte M M; Visser, Eric J W; St Onge, Kate R; Voesenek, Laurentius A C J; Pierik, Ronald

2013-02-01

116

Current and electromagnetic field associated with lightning-return strokes to tall towers  

Microsoft Academic Search

An analysis of electric and magnetic fields radiated by lightning first and subsequent return strokes to tall towers is presented. The contributions of the various components of the fields, namely, static, induction, and radiation for the electric field, and induction and radiation for the magnetic field are illustrated and discussed. It is shown in particular that the presence of a

Farhad Rachidi; Wasyl Janischewskyj; Ali M. Hussein; Carlo Alberto Nucci; Silvia Guerrieri; Behzad Kordi; Jen-Shih Chang

2001-01-01

117

Therapeutic Targeting of c-Myc in T-Cell Acute Lymphoblastic Leukemia (T-ALL)  

PubMed Central

T-ALL patients treated with intensive chemotherapy achieve high rates of remission. However, frequent long-term toxicities and relapses into chemotherapy-refractory tumors constitute major clinical challenges which could be met by targeted therapies. c-MYC is a central oncogene in T-ALL, prompting the exploration of the efficacy of MYC inhibitors such as JQ1 (BET-bromodomain inhibitor), and SAHA (HDAC inhibitor). Using a standardized ex vivo drug screening assay, we show here that JQ1 and SAHA show competitive efficiency compared to inhibitors of proteasome, PI3K/AKT/mTOR and NOTCH pathways, and synergize in combination with Vincristine. We also compared for the first time the in vivo relevance of such associations in mice xenografted with human primary T-ALLs. Our data indicate that although treatments combining JQ1 or SAHA with chemotherapeutic regimens might represent promising developments in T-ALL, combinations will need to be tailored to specific subgroups of responsive patients, the profiles of which still remain to be precisely defined.

Goubard, Armelle; Crouzet, Thomas; Pouyet, Laurent; Prebet, Thomas; Vey, Norbert

2014-01-01

118

Hijacking T cell differentiation: new insights in TLX function in T-ALL.  

PubMed

TLX1 and TLX3 are two closely-related homeobox transcriptional repressors frequently misexpressed and translocated in T cell acute lymphoblastic leukemia (T-ALL). In this issue of Cancer Cell, Dadi et al. provide new insights into how these factors are recruited by ETS-1 to the TCR? enhancer and actively repress differentiation. PMID:22516255

King, Bryan; Ntziachristos, Panagiotis; Aifantis, Iannis

2012-04-17

119

Suspended chains damp wind-induced oscillations of tall flexible structures  

NASA Technical Reports Server (NTRS)

Hanging-chain system, which is a form of impact damper, suppresses wind-induced bending oscillations of tall cylindrical antenna masts. A cluster of chains enclosed in a neoprene shroud is suspended inside the tip of the antenna mast, forming a simple method of damping structural vibrations.

Reed, W. H., III

1968-01-01

120

Sound pressure level attenuation provided by thin rigid screens coupled to tall buildings  

Microsoft Academic Search

This paper computes the sound pressure attenuation provided by thin rigid screens placed on the walls of a tall building to protect the building from the direct sound incidence produced by sound pressure sources placed in its vicinity. The problem is formulated in the frequency domain via the Traction Boundary Element Method (TBEM), which overcomes the thin-body difficulty arising with

A. Tadeu; J. António; P. Amado Mendes; L. Godinho

2007-01-01

121

View of worlds tallest totem pole, 136.5 feet tall. First ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of worlds tallest totem pole, 136.5 feet tall. First potlatch pole since 1904. Dedicated to all things and all peoples of southeast Alaska, 1971. Oct potlatch, looking northwest - Kake Salmon Cannery, Totem Pole, Kake, Wrangell-Petersburg Census Area, AK

122

Long-term tall tower carbon dioxide flux monitoring over an area of mixed vegetation  

Microsoft Academic Search

A methodology is described to determine the carbon budget of an extended region with mixed vegetation. The eddy covariance measuring system is operated at 82m elevation on a tall radio\\/television transmitter tower above an area covered by agricultural fields and forest patches. The methodology ensuring the high quality of the calculated fluxes is described. Net ecosystem exchange (NEE) of CO2

L. Haszpra; Z. Barcza; K. J. Davis; K. Tarczay

2005-01-01

123

Phytomass structure of natural plant communities on spodosols in southern Venezuela: The tall Amazon Caatinga forest  

Microsoft Academic Search

The phytomass structure of the evergreen lowland forest vegetation (Tall Amazon Caatinga) supported by tropaquods near San Carlos de Rio Negro, Federal Amazon Territory of Venezuela was studied in 13 10 m× 10 m plots. The plots were laid out subjectively to cover a low topographical gradient along which the forest on tropaquod is grading into a low woodland (Bana,

H. Klinge; R. Herrera

1983-01-01

124

Yield Characteristics of Biodiesel Produced from Chicken Fat-Tall Oil Blended Feedstocks. Final Report.  

National Technical Information Service (NTIS)

The primary objective of this study was to investigate the conversion of chicken fat and tall oil, both individually and in a blend, into biodiesel. The conventional base-catalyzed method of biodiesel production has shown to be inappropriate for the conve...

E. C. Clausen M. Popp R. E. Babcock W. B. Schulte

2008-01-01

125

Nitrogen Effects on Leaf Anatomy within the Intercalary Meristems of Tall Fescue Leaf Blades  

Microsoft Academic Search

Longitudinal elongation contributes most to leaf area expansion of grasses and its rate is known to be strongly affected by N. Our objective was to determine the effect of two N regimes (N0and N+) on the gradient of leaf tissue formation in meristems of two contrasting tall fescue (Festuca arundinacea Schreb.) genotypes. Proportions of epidermal, mesophyll and vascular tissue as

Ingo F. Rademacher; C. Jerry Nelson

2001-01-01

126

Wind engineering challenges of the new generation of super-tall buildings  

Microsoft Academic Search

The new generation of tall buildings is going much higher than before. This poses new challenges for wind engineering. The boundary layer models in many building codes and standards have served well for buildings less than about 300m but more realistic models need to be used above 300m. The statistics of upper level winds need also to be known with

Peter A. Irwin

2009-01-01

127

TALL FESCUE RESPONSE AND SOIL PROPERTIES FOLLOWING SOIL AMENDMENT WITH TANNERY WASTES  

EPA Science Inventory

Field plots were established in 1978 and 1979 on a Willamette sil in western Oregon to evaluate the effects of chrome tannery wastes on tall fescue (Festuca arundinacea) and soil properties. Three rates of waste material were applied each year; N, Ca, Mg, Cu, Cr, Mn, and Zn in so...

128

Determining optimal seeding times for tall fescue using germination studies and spatial climate analysis  

Microsoft Academic Search

This paper describes a new approach for determining optimal seeding times using laboratory-based germination studies and spatial climate analysis, with tall fescue as the test species and China as the targeted application area. Since temperature is one of a number of influential environmental factors for germination and establishment of grass species, experiments were conducted to determine the effect of temperature

Hongfei Lu; Jinbo Shen; Xiaoqian Jin; David B. Hannaway; Christopher Daly; Michael D. Halbleib

2008-01-01

129

Evolutionary Optimization of Braced Steel Frameworks for Tall Buildings Using a Hybrid OC-GA Method  

Microsoft Academic Search

Having many attractive advantages, genetic algorithms (GAs) have been applied to many design optimization problems. However, the practical application of GAs to realistic tall building design is still rather limited, since GAs require a large number of structural reanalyses and perform poorly in local searching. While the Optimality Criteria (OC) method can be applied effectively to the element sizing optimization

C.-M. Chan; K.-M. Wong

130

Using radiosonde meteorological data to better assess air conditioning loads in tall buildings  

Microsoft Academic Search

Considering radiosonde-observed lower atmosphere air temperature and specific humidity data in support of isolated tall building's air conditioning (AC) planning, is suggested. Procedures to process such data and several illustrations of their utilization for summer afternoon meteorological conditions are provided. The constraints involved with the utilization of radiosonde data are discussed. Coastal and continental locations in the US, as represented

Moti Segal; Richard Turner; Dennis Todey

2000-01-01

131

Screening strategy to avoid toxicological hazards of inhaled nanoparticles for drug delivery: The use of a-quartz and nano zinc oxide particles as benchmark  

NASA Astrophysics Data System (ADS)

Nanotechnology is a broad, revolutionary field with promising advantages for new medicine. In this context the rapid development and improvement of so called nanocarriers is of high pharmaceutical interest and some devices are already on the market. In our project we aim to develop well characterized nanoscaled drug delivery systems for an inhalative application. To this end, we focus on the most adverse side-effects within the lung, the cytotoxic and the proinflammatory responses to these nanoparticles (NPs). Before performing any animal experiments, we start with an in vitro screening for analyzing the cytotoxic and proinflammatory effects of the investigated particles on two murine lung target cell lines, the alveolar epithelial like typ II cell line (LA4) and the alveolar macrophage cell line (MH-S). Three different endpoints were estimated, (i) cellular metabolic activity, determined by the WST-1 assay, (ii) membrane integrity, by detection of LDH release and hemolytic activity, and (iii) secretion of inflammatory mediators. To analyze the relative particle toxicity we choose two reference particles as benchmarks, (i) fine a-quartz, and (ii) ultrafine ZnO particles. The investigation of dose-response and kinetics of proinflammatory and toxic effects caused to the named cell lines provide an insight to a close evaluation of our cell based screening strategy. oc-quartz is well known for its inflammatory and toxic potential caused by inhalation, and nanosized ZnO particles - used in a broad field of nanotechnology like electronics, but also cosmetics and pharmaceuticals - is to a high degree cytotoxic and proinflammatory in vitro. Preliminary experiments indicated not only particle and cell specific inflammatory responses, but also different susceptibilities of the cell types being exposed to our benchmark particles regarding their size and surface activities. Exposure to the ?m-sized a-quartz particles affected the viability of epithelia cells less than that of macrophages, pointing to the impact of particle uptake by phagocytosis. In contrast, the nanosized ZnO particles caused much stronger decrease in cell viability and higher levels of LDH in the macrophage cell line compared to epithelial cells, even though the hemolytic activity was much higher for the a-quartz particles than for the nanosized ZnO. For the proinflammatory effects, we observed a clear dose-dependent release of acute phase cytokines (TNF-?, IL-6, G-CSF> CXCL10>CCL2) for both alveolar cell lines after Min-U-Sil exposure. After ZnO treatment the cytokine responses were negligible compare to control cells. In conclusion, our data attach value to the use of different cell types to detect different pathways of toxicity generated by different particle properties. Therefore, we will establish both lung target cell lines for an in vitro screening to analyze proinflammatory and cytotoxicity effects of nanocarriers. The implementation of the two reference particles facilitate the validated classification of the cytotoxic responses caused by the NPs investigated.

Beyerle, Andrea; Schulz, Holger; Kissel, Thomas; Stoeger, Tobias

2009-02-01

132

caNanoLab  

Cancer.gov

Welcome to the cancer Nanotechnology Laboratory (caNanoLab) portal. caNanoLab is a data sharing portal designed to facilitate information sharing in the biomedical nanotechnology research community to expedite and validate the use of nanotechnology in biomedicine. caNanoLab provides support for the annotation of nanomaterials with characterizations resulting from physico-chemical and in vitro assays and the sharing of these characterizations and associated nanotechnology protocols in a secure fashion.

133

Notch1 signaling is involved in regulating Foxp3 expression in T-ALL  

PubMed Central

Background T-cell acute lymphoblastic leukemia (T-ALL) is a highly aggressive hematologic malignancy. Immune tolerance induced by CD4+CD25+ regulatory T cells (Tregs) with high expression of Foxp3 is an important hypothesis for poor therapy response. Notch1 signaling is thought to be involved in the pathogenesis of this disease. Crosstalk between Notch and Foxp3+Tregs induced immune tolerance is unknown in T-ALL. We studied Foxp3 and Notch1 expression in vivo and in vitro, and analyzed the biological characteristics of T-ALL cell line systematically after Notch inhibition and explored the crosstalk between Notch signaling and Foxp3 expression. Methods In vivo, we established T-ALL murine model by Jurkat cells transplantation to severe combined immunodeficiency (SCID) mice. Notch1 and Foxp3 expression was detected. In vitro, we used ?-secretase inhibitor N-S-phenyl-glycine-t-butyl ester (DAPT) to block Notch1 signaling in Jurkat cells. Notch1, Hes-1 and Foxp3 genes and protein expression were detected by PCR and western blotting, respectively. The proliferation pattern, cell cycle and viability of Jurkat cells after DAPT treatment were studied. Protein expression of Notch1 target genes including NF-?B, p-ERK1/2 and STAT1 were determined. Results We show that engraftment of Jurkat cells in SCID mice occurred in 8 of 10 samples (80%), producing disseminated human neoplastic lymphocytes in PB, bone marrow or infiltrated organs. Notch1 and Foxp3 expression were higher in T-ALL mice than normal mice. In vitro, Jurkat cells expressed Notch1 and more Foxp3 than normal peripheral blood mononuclear cells (PBMCs) in both mRNA and protein levels. Blocking Notch1 signal by DAPT inhibited the proliferation of Jurkat cells and induced G0/G1 phase cell cycle arrest and apoptosis. Foxp3 as well as p-ERK1/2, STAT1 and NF-?B expression was down regulated after DAPT treatment. Conclusions These findings indicate that regulation of Foxp3 expression does involve Notch signaling, and they may cooperatively regulate T cell proliferation in T-ALL.

2013-01-01

134

Exploring Products: Nano Sand  

NSDL National Science Digital Library

In this activity, learners explore how water behaves differently when it comes in contact with "nano sand" and regular sand. Learners learn about the hydrophobic properties of "nano sand." Use this activity to talk about how many materials behave differently at the nanoscale.

Network, Nanoscale I.; Sciencenter

2010-01-01

135

Exploring Products: Nano Fabrics  

NSDL National Science Digital Library

In this activity, learners explore how the application of nano-sized "whiskers" can protect clothing from stains. Learners investigate the hydrophobic properties of pants made from nano fabric and ordinary fabric. Use this activity to talk about products that we can already buy that use nanotechnology, like treated fabrics, water filters, sunscreen and stuffed animals that have silver nanoparticles.

Network, Nanoscale I.; Sciencenter

2010-01-01

136

Estimating daytime CO2 fluxes over a mixed forest from tall tower mixing ratio measurements  

Microsoft Academic Search

Difficulties in estimating terrestrial ecosystem CO2 fluxes on regional scales have significantly limited our understanding of the global carbon cycle. This paper presents an effort to estimate daytime CO2 fluxes over a forested region on the scale of 50 km in northern Wisconsin, USA, using the tall-tower-based mixed layer (ML) budget method. Budget calculations were conducted for 2 years under

Weiguo Wang; Kenneth J. Davis; Bruce D. Cook; Chuixiang Yi; Martha P. Butler; Daniel M. Ricciuto; Peter S. Bakwin

2007-01-01

137

Long-Acting Lanreotide in Adolescent Girls with Constitutional Tall Stature  

Microsoft Academic Search

Background\\/Aims: The aim of the study was to evaluate the efficacy and safety of lanreotide prolonged release (PR) 30 mg (long-acting lanreotide) in girls with constitutional tall stature (CTS). Methods: This open label prospective study included 35 girls (mean age 12.6 years) with CTS and a predicted adult height of >180 cm. Intramuscular injections of lanreotide PR 30 mg were

Jean-Claude Carel; Joëlle Blumberg; Muriel Bougeard-Julien; Pierre Rochiccioli; Jean-Louis Chaussain; Maïthé Tauber

2009-01-01

138

Nitrogen EÄects on Leaf Anatomy within the Intercalary Meristems of Tall Fescue Leaf Blades  

Microsoft Academic Search

Longitudinal elongation contributes most to leaf area expansion of grasses and its rate is known to be strongly aÄected by N. Our objective was to determine the eÄect of two N regimes (N0 and Ná) on the gradient of leaf tissue formation in meristems of two contrasting tall fescue (Festuca arundinacea Schreb.) genotypes. Proportions of epidermal, mesophyll and vascular tissue

INGO F. RADEMACHER; C. JERRY NELSON

2001-01-01

139

Simulation of lightning attachment to open ground, tall towers and aircraft  

SciTech Connect

The characteristics of lightning waveforms are important in taking protective measures against it. However, many of these characteristics cannot be measured. This paper employs a mathematical model of lightning currents to write a software package to simulate all manner of lightning flashes. The capabilities available to us through this are demonstrated by extracting the behavior of lightning waveforms following attachment to open ground, tall towers and aircraft.

Ratnamahilan, P.; Hoole, P. (Univ. of Technology, Lae (Papua New Guinea). Dept. of Electrical and Telecommunications Engineering); Ratnajeevan, S.; Hoole, H. (Harvey Mudd College, Claremont, CA (United States). Dept. of Engineering)

1993-04-01

140

Boussinesq approximations, and beyond, in a tall thermo-gravitational column  

NASA Astrophysics Data System (ADS)

This article focuses on the main aspects of the non-Boussinesq treatment that is required for analyzing the simplest flow regimes occurring in a tall thermo-gravitational column, when the Soret coefficient S is considered as depending upon temperature and composition, S(T,C). As a main result, the horizontal dynamics is mainly governed by the Soret thermal sensitivity, and the species vertical separation by its compositional one. To cite this article: G. Labrosse, C. R. Mecanique 335 (2007).

Labrosse, Gérard

2007-09-01

141

Simplified displacement demand prediction of tall asymmetric buildings subjected to long-distance earthquakes  

Microsoft Academic Search

Large-magnitude long-distance earthquakes generated from Sumatra have significant potential engineering implications in Singapore and the Malaysian Peninsula due to accentuation by resonance in both the soil and buildings, and importantly, dynamic torsional amplification of elastic response of tall buildings.This paper introduces a simple assessment procedure which accounts for these amplification mechanisms particularly the effects on dynamic torsional coupling. In the

T. Balendra; N. T. K. Lam; M. J. Perry; E. Lumantarna; J. L. Wilson

2005-01-01

142

Comparative Criteria for Models of the Vascular Transport Systems of Tall Trees  

Microsoft Academic Search

\\u000a During the past decade, several detailed models of plant vascular transport systems (i.e. xylem and phloem) have been presented\\u000a in the literature, and many of them are currently capable of accurately modelling the hydraulic characteristics of trees,\\u000a including tall trees. This marks a departure from earlier modelling exercises in plant water relations, when models were intended\\u000a primarily to promote an

Maurizio Mencuccini; Teemu Hölttä; Jordi Martinez-Vilalta

143

Greenhouse gases measurements at Zotino Tall Tower Observatory (ZOTTO) in central Siberia  

NASA Astrophysics Data System (ADS)

Boreal ecosystems play a crucial role in atmospheric carbon budget calculations as they represent about one third of the Earth's forested land surface area and are typically a net sink of carbon dioxide and a net source of methane. However, direct measurements of carbon dioxide, water vapor, and methane in large areas of the boreal zone, such as Central Siberia, are sparse and unevenly distributed in space. In order to improve the spatial coverage and representativeness of flux estimates and reduce their uncertainty, our group has begun eddy covariance measurements to complement our tall tower measurements in Central Siberia. The Zotino Tall Tower Observatory (ZOTTO, www.zottoproject.org) measurement site is located in pristine taiga near the Yenisei river (60°48'N, 89°21'E). The ZOTTO tall tower is equipped with continuous, low-maintenance CO2/CH4 concentration measurements by cavity ring down spectroscopy (CRDS) from six heights up to 301 m since May 2009. Additionally, we have set up two eddy covariance flux measurement systems in the forest and in the bog, located 1 and 3 km from the tall tower, respectively. Both towers are equipped with an enclosed CO2/H2O gas analyzer and ultrasonic anemometers. The bog tower includes a CH4 eddy covariance gas analyzer. Here, we report atmospheric CO2 and CH4 concentrations, focusing on growing season of 2012. The net ecosystem exchange (NEE) and evapotranspiration in boreal forest eddy site, and carbon fluxes in the wetland area (60°49'N, 89°23'E) are examined in terms of their relationship with major controlling factors such as temperature, photosynthetically active radiation, vapor pressure deficits, soil moisture, and friction velocity.

Park, Sung-Bin; Lavri?, Jošt V.; Kolle, Olaf; Vesala, Timo; Panov, Alexey; Heimann, Martin

2014-05-01

144

Near?noon albedo values of alfalfa and tall fescue grass derived from multispectral data  

Microsoft Academic Search

A remote sensing approach was applied to estimate near?noon values of shortwave albedo (?), the fraction of solar radiation reflected by a surface, for alfalfa and tall fescue grass at Kimberly, Idaho. The approach was based on the (P\\/T) ratio, which is the ratio of the partial radiation (P) sensed by a multi?band radiometer and the total incident radiation (T)

J. O. Payero; C. M. U. Neale; J. L. Wright

2006-01-01

145

Volatile compounds of endophyte-free and infected tall fescue ( Festuca arundinacea Schreb.)  

Microsoft Academic Search

Volatile compounds produced by intact plants and ground leaf tissue from endophyte-infected (E+) and endophyte-free (E?) tall fescue (Festuca arundinacea Schreb.) were collected by a purge-and-trap procedure and analyzed by gas chromatography\\/mass spectrometry The volatile compound profile from ground leaf tissue was similar between E+ and E? clonal plants; however, the sheaths of E+ clonal plants produced higher levels of

Qin Yue; Chunlin Wang; Thomas J Gianfagna; William A Meyer

2001-01-01

146

Adult height in constitutionally tall stature: accuracy of five different height prediction methods  

Microsoft Academic Search

The accuracy of height predictions at various ages based on five different methods (Tanner-Whitehouse mark I; Tanner-Whitehouse mark II; index of potential height; Bayley-Pinneau; Roche-Wainer-Thissen) was compared at yearly intervals with final height achieved in 32 boys (78 predictions) and 100 girls (227 predictions) with constitutionally tall stature. The boys were initially seen at a mean (SD) chronological age of

E E Joss; R Temperli; P E Mullis

1992-01-01

147

Particleboard quality characteristics of saline jose tall wheatgrass and chemical treatment effect  

Microsoft Academic Search

The objective of this research was to characterize the qualities (mechanical properties and water resistance) of particleboard made from saline Jose Tall Wheatgrass (JTW), Agropyron elongatum. For the JTW particleboards made with 4% polymeric methane diphenyl diisocyanate (PMDI), the mechanical properties and water resistance improved with the increase of particleboard density from 0.71 to 0.75g\\/cm3. The particleboards with density of

Yi Zheng; Zhongli Pan; Ruihong Zhang; Bryan M. Jenkins; Sherry Blunk

2007-01-01

148

Air and water pollution control in crude tall oil manufacture in the pulp and paper industry  

Microsoft Academic Search

Pollution preventive measures should be built into the process when a new mill is designed; corrective measures must be taken\\u000a on existing mills. For air pollution control, these measures consist essentially of enclosing all vessels that contain the\\u000a black liquor from which the tall oil is recovered. Hoods are placed over storage tanks, sumps, heat exchangers, and other\\u000a liquor-containing vessels.

J. P. Krumbein; A. B. Adams

1973-01-01

149

An optimality criteria algorithm for tall steel building design using commercial standard sections  

Microsoft Academic Search

Grierson and Chan (1991a, b) recently presented an efficient optimality criteria (OC) technique for the optimum design of large-scale tall steel building frameworks. In this paper, further developments of the technique are described concerning a detailed procedure to assign optimum discrete section sizes to structural members. A 60-storey, 7-bay framework example is presented to illustrate the practical applicability and efficiency

C.-M. Chan

1992-01-01

150

Prognostic Outcomes of Tall Cell Variant Papillary Thyroid Cancer: A Meta-Analysis  

PubMed Central

Objective. To evaluate the prognosis of tall cell variant (TCV) compared to usual variant (UV) papillary thyroid cancer by comparing disease-related mortality and recurrence data from published studies. Methods. Ovid MEDLINE keyword search using “tall cell variant papillary thyroid cancer” was used to identify studies published in English that calculated disease-related mortality and recurrence rates for both TCV and UV. Results. A total of 131 cases of tall cell variant papillary thyroid cancer were reviewed. The combined odds ratio of recurrence for TCV compared to UV is 4.50 with a 95% confidence interval from 2.90 to 6.99. For disease-related mortality, the combined odds ratio for TCV was compared to UV of 14.28 with a 95% confidence interval from 8.01 to 25.46. Conclusion. Currently published data suggests that TCV is a negative prognostic indicator in papillary thyroid cancer and requires aggressive therapy. This meta-analysis provides the largest prognostic data series on TCV in the literature and clearly identifies the need for accurate pathological identification of TCV and its further study as an independent prognostic factor.

Jalisi, Scharukh; Ainsworth, Tiffiny; LaValley, Michael

2010-01-01

151

Prognostic Significance of NOTCH1 and FBXW7 Mutations in Pediatric T-ALL  

PubMed Central

The NOTCH signaling pathway plays important role in the development of multicellular organisms, as it regulates cell proliferation, survival, and differentiation. In adults, it is essential for the T- or B-lymphocyte lineage commitment. NOTCH1 and FBXW7 mutations both lead the activation of the NOTCH1 pathway and are found in the majority of T-ALL patients. In this study, the mutation analysis of NOTCH1 and FBXW7 genes was performed in 87 pediatric T-ALLs who were treated on the ALL-BFM protocols. In 19 patients (22%), activating NOTCH1 mutations were observed either in the heterodimerization domain or in the PEST domain and 7 cases (10%) demonstrated FBXW7 mutations (2 cases had both NOTCH1 and FBXW7 mutations). We also analyzed the relationship of the mutation data between the clinical and biological data of the patients. NOTCH1 and FBXW7, NOTCH1 alone were found correlated with lower initial leucocyte counts which was independent from the sex and T- cell immunophenotype. However, NOTCH1 and FBXW7 mutations were not predictive of outcome in the overall cohort of pediatric T-ALLs.

Erbilgin, Yucel; Sayitoglu, Muge; Hatirnaz, Ozden; Dogru, Omer; Akcay, Arzu; Tuysuz, Gulen; Celkan, Tiraje; Aydogan, Gonul; Salcioglu, Zafer; Timur, Cetin; Yuksel-Soycan, Lebriz; Ure, Umit; Anak, Sema; Agaoglu, Leyla; Devecioglu, Omer; Yildiz, Inci; Ozbek, Ugur

2010-01-01

152

Application of ceilometers to retrieve planetary boundary layer height near tall-tower sites  

NASA Astrophysics Data System (ADS)

Tall tower measurement sites can provide continuous records of various climate-relevant atmospheric gases like CO2, CH4, CO, N2O, or SF6 at different altitude levels. With the help of inverse transport models, the results can be used to determine sources and sinks of important greenhouse gases. Several tall tower sites with heights around 300 m have been established in Poland, Germany and France. Depending on the height of the tower and meteorological conditions, the different levels are influenced by air masses on a local to synoptic scale. A critical parameter for the analysis of the data is the planetary boundary layer height (PBL). If the top of the tower is still inside the PBL the measurements at the top level would be mostly influenced by local to regional sources and sinks. If the top is already in the free troposphere the measurements would be influenced by long-range transport. However, the PBL height cannot be derived from the tower measurements alone. Within the preparations for the Integrated Carbon Observing System (ICOS), several methods for determining PBL height near tall tower sites have been evaluated. During a campaign in France in October 2008, lidar systems, radio sondes as well as two different commercial ceilometers (Vaisala CL31 and Jenoptik CHM15k) were run side-by-side. One goal of the campaign was to find out if and how ceilometers could be used to retrieve PBL height operationally and if they should become part of future ICOS network sites.

Biavati, G.; Feist, D. G.; Heimann, M.

2009-04-01

153

Quantification of ergovaline using HPLC and mass spectrometry in Iranian Neotyphodium infected tall fescue.  

PubMed

Ergovaline, the main ergopeptine alkaloid produced in tall fescue (Fescue arundinacea Schreb.) infected with endophyte (Neotyphodium coenophialum Morgan- Jones & Gams), is known to cause tall fescue toxicosis. This study was conducted to examine the presence of fungal endophytes in five populations of tall fescue collected from various regions of Iran. The existence of Neotyphodium mycelia in the tissues of the samples was confirmed by microscopic examination, and the isolation was performed from leaf tissues of the hosts on potato dextrose agar. All isolates were confirmed as the Neotyphodium species by PCR, using specific primers. Mass detection and determination of ergovaline were performed by HPLC at three plant growth stages. Ergovaline was detected in all isolates, with the mean concentrations of 0.24 to 3.48 ?g/g dry matter of different populations for the whole three plant growth stages. The differences in ergovaline content between plant populations and sampling time were statistically significant. This is the first report of ergovaline content in endophyte infected Fescue arundinacea from natural grasslands in Iran. PMID:22049272

Najafabadi, A Sobhani; Mofid, M R; Mohammadi, R; Moghim, S

2010-07-01

154

Transgenic Expression of MsHsp23 Confers Enhanced Tolerance to Abiotic Stresses in Tall Fescue  

PubMed Central

Tall fescue (Festuca arundinacea Schreb.) is an important cool season forage plant that is not well suited to extreme heat, salts, or heavy metals. To develop transgenic tall fescue plants with enhanced tolerance to abiotic stress, we introduced an alfalfa Hsp23 gene expression vector construct through Agrobacterium-mediated transformation. Integration and expression of the transgene were confirmed by polymerase chain reaction, northern blot, and western blot analyses. Under normal growth conditions, there was no significant difference in the growth of the transgenic plants and the non-transgenic controls. However, when exposed to various stresses such as salt or arsenic, transgenic plants showed a significantly lower accumulation of hydrogen peroxide and thiobarbituric acid reactive substances than control plants. The reduced accumulation of thiobarbituric acid reactive substances indicates that the transgenic plants possessed a more efficient reactive oxygen species-scavenging system. We speculate that the high levels of MsHsp23 proteins in the transgenic plants protect leaves from oxidative damage through chaperon and antioxidant activities. These results suggest that MsHsp23 confers abiotic stress tolerance in transgenic tall fescue and may be useful in developing stress tolerance in other crops.

Lee, Ki-Won; Choi, Gi Jun; Kim, Ki-Yong; Ji, Hee Jung; Park, Hyung Soo; Kim, Yong-Goo; Lee, Byung Hyun; Lee, Sang-Hoon

2012-01-01

155

Full-scale monitoring of typhoon effects on super tall buildings  

NASA Astrophysics Data System (ADS)

This paper presents the field measurement results of wind characteristics and structural responses of two super tall buildings, Central Plaza Tower (374 m, 78 floors) in Hong Kong and Di Wang Tower (384 m, 78 floors) in Shenzhen during the passage of Typhoon Sally. The field data such as wind speeds, wind directions and acceleration responses were simultaneously and continuously measured from the tall buildings during the typhoon. Detailed analysis of the field data and comparative study were conducted to investigate the characteristics of typhoon-generated wind over the two cities and wind-induced vibrations of the two super tall buildings under typhoon condition. The dynamic characteristics of the buildings were determined on the basis of the field measurements and comparisons with those calculated from the computational models of the buildings were made. The damping ratios of the buildings were estimated and the amplitude-dependent damping characteristics are presented and discussed. Furthermore, the full-scale measurements were compared with the wind tunnel results to evaluate the accuracy of the model test results and the adequacy of the techniques used in wind tunnel tests.

Li, Q. S.; Xiao, Y. Q.; Wong, C. K.

2005-07-01

156

The effect of amplitude-dependent damping on wind-induced vibrations of a super tall building  

Microsoft Academic Search

Full-scale measurements of wind effects on a 70 storey tall building have been conducted. The tall building that has a height of 367m is the second tallest structure in Hong Kong. The amplitude-dependent characteristics of damping have been obtained by using the random decrement technique from the field measurements of acceleration responses. The objective of this study is to present

Q. S. Li; Ke. Yang; C. K. Wong; A. P. Jeary

2003-01-01

157

How Do Changes in Leaf\\/Shoot Morphology and Crown Architecture Affect Growth and Physiological Function of Tall Trees?  

Microsoft Academic Search

\\u000a With increasing height within the crowns of tall trees, leaves tend to become smaller and thicker and shoots shorter. In tall\\u000a trees, the vertical variation in leaf\\/shoot morphology is largely driven by water status. Morphological changes associated\\u000a with increasing height in the crown present static constraints on photosynthesis, such as decreasing light intercepting area\\u000a relative to leaf mass and decreasing

Hiroaki Ishii

158

TALL1 is a novel member of the TNF family that is down-regulated by mitogens  

Microsoft Academic Search

Members of the tumor necrosis factor (TNF) family play important roles in modulation of immune responses. We describe the identification and cloning of a novel TNF family member that has been designated as TALL-1. TALL-1 is a 285-amino acid type II transmembrane protein. Its carboxy terminus shares D35% sequence identity with the recently identified APRIL and D20-25% with TNF, FasL,

Hong-Bing Shu; Wen-Hui Hu; Holly Johnson

159

A cooperative microRNA-tumor suppressor gene network in acute T-cell lymphoblastic leukemia (T-ALL).  

PubMed

The importance of individual microRNAs (miRNAs) has been established in specific cancers. However, a comprehensive analysis of the contribution of miRNAs to the pathogenesis of any specific cancer is lacking. Here we show that in T-cell acute lymphoblastic leukemia (T-ALL), a small set of miRNAs is responsible for the cooperative suppression of several tumor suppressor genes. Cross-comparison of miRNA expression profiles in human T-ALL with the results of an unbiased miRNA library screen allowed us to identify five miRNAs (miR-19b, miR-20a, miR-26a, miR-92 and miR-223) that are capable of promoting T-ALL development in a mouse model and which account for the majority of miRNA expression in human T-ALL. Moreover, these miRNAs produce overlapping and cooperative effects on tumor suppressor genes implicated in the pathogenesis of T-ALL, including IKAROS (also known as IKZF1), PTEN, BIM, PHF6, NF1 and FBXW7. Thus, a comprehensive and unbiased analysis of miRNA action in T-ALL reveals a striking pattern of miRNA-tumor suppressor gene interactions in this cancer. PMID:21642990

Mavrakis, Konstantinos J; Van Der Meulen, Joni; Wolfe, Andrew L; Liu, Xiaoping; Mets, Evelien; Taghon, Tom; Khan, Aly A; Setty, Manu; Setti, Manu; Rondou, Pieter; Vandenberghe, Peter; Delabesse, Eric; Benoit, Yves; Socci, Nicholas B; Leslie, Christina S; Van Vlierberghe, Pieter; Speleman, Frank; Wendel, Hans-Guido

2011-07-01

160

Repression of tumor suppressor miR-451 is essential for NOTCH1-induced oncogenesis in T-ALL.  

PubMed

The NOTCH1 signaling pathway is a critical determinant of cell fate decisions and drives oncogenesis through mechanisms that are incompletely understood. Using an established mouse model of T cell acute lymphoblastic leukemia (T-ALL), here we report that induction of intracellular Notch1 (ICN1) leads to repression of miR-451 and miR-709. ICN1 decreases expression of these miRNAs by inducing degradation of the E2a tumor suppressor, which transcriptionally activates the genes encoding miR-451 and miR-709. Both miR-451 and miR-709 directly repress Myc expression. In addition, miR-709 directly represses expression of the Akt and Ras-GRF1 oncogenes. We also show that repression of miR-451 and miR-709 expression is required for initiation and maintenance of mouse T-ALL. miR-451 but not miR-709 is conserved in humans, and human T-ALLs with activating NOTCH1 mutations have decreased miR-451 and increased MYC levels compared with T-ALLs with wild-type NOTCH1. Thus, miR-451 and miR-709 function as potent suppressors of oncogenesis in NOTCH1-induced mouse T-ALL, and miR-451 influences MYC expression in human T-ALL bearing NOTCH1 mutations. PMID:21464222

Li, Xiaoyu; Sanda, Takaomi; Look, A Thomas; Novina, Carl D; von Boehmer, Harald

2011-04-11

161

PREFACE: Nano and microfluidics Nano and microfluidics  

Microsoft Academic Search

The field of nano- and microfluidics emerged at the end of the 1990s parallel to the demand for smaller and smaller containers and channels for chemical, biochemical and medical applications such as blood and DNS analysis [1], gene sequencing or proteomics [2, 3]. Since then, new journals and conferences have been launched and meanwhile, about two decades later, a variety

Karin Jacobs

2011-01-01

162

Nano-electromembrane extraction.  

PubMed

The present work has for the first time described nano-electromembrane extraction (nano-EME). In nano-EME, five basic drugs substances were extracted as model analytes from 200 ?L acidified sample solution, through a supported liquid membrane (SLM) of 2-nitrophenyl octyl ether (NPOE), and into approximately 8 nL phosphate buffer (pH 2.7) as acceptor phase. The driving force for the extraction was an electrical potential sustained over the SLM. The acceptor phase was located inside a fused silica capillary, and this capillary was also used for the final analysis of the acceptor phase by capillary electrophoresis (CE). In that way the sample preparation performed by nano-EME was coupled directly with a CE separation. Separation performance of 42,000-193,000 theoretical plates could easily be obtained by this direct sample preparation and injection technique that both provided enrichment as well as extraction selectivity. Compared with conventional EME, the acceptor phase volume in nano-EME was down-scaled by a factor of more than 1000. This resulted in a very high enrichment capacity. With loperamide as an example, an enrichment factor exceeding 500 was obtained in only 5 min of extraction. This corresponded to 100-times enrichment per minute of nano-EME. Nano-EME was found to be a very soft extraction technique, and about 99.2-99.9% of the analytes remained in the sample volume of 200 ?L. The SLM could be reused for more than 200 nano-EME extractions, and memory effects in the membrane were avoided by effective electro-assisted cleaning, where the electrical potential was actively used to clean the membrane. PMID:23764444

Payán, María D Ramos; Li, Bin; Petersen, Nickolaj Jacob; Jensen, Henrik; Hansen, Steen Honoré; Pedersen-Bjergaard, Stig

2013-06-27

163

Building Tall  

NSDL National Science Digital Library

In this engineering activity (page 2 of PDF), young learners investigate how a wide base can make a building more stable. Learners use blocks or boxes of different sizes to construct stable towers. Learners will compare and contrast different structures, document their observations, experiment with different materials, and conduct stability tests. This activity is part of the Curious George "Under Construction" lesson plan and related to the show Curious George on PBS, specifically the episode "Curious George's Home for Pigeons." The lesson plan includes several activities that explore building engineering. Activities are connected to fiction and non-fiction books and include family extension projects.

Kids, Pbs

2006-01-01

164

Tall oil precursors and turpentine in Jack and Eastern White Pine  

SciTech Connect

The tall oil precursors and turpentine from jack pine (Pinus banksiana Lamb.) and eastern white pine (Pinus strobus L.) were investigated. The tall oil precursors (resin acids, fatty acids, and unsaponifiables were determined by chemical fractionation of the nonvolatile diethyl ether extractives (NVEE) of these speices: (approximate % resin acids, % fatty acids, % unsaponifiables, and % acids other that fatty and resin acids) - jack pine sapwood (10, 60, 10, 20%), heartwood (38, 12, 6, 44%); eastern white pine sapwood (11, 57, 9, 22%), and heartwood (11, 18, 10, 62%). The resin acids were a mixture of the pimaric and abietic acids common to pines. In addition, eastern white pine contained major amounts of the resin acid, anticopalic acid. The fatty acids were predominately oleic, linoleic, and 5, 9, 12-octadecatrienoic acids. The unsaponsiables were a complex mixture of diterpenes and sterols (mainly campesterol and sitosterol). On treating these species with paraquat, lightwood occurred in the sapwood but not in the heartwood areas as we have oberved with other pines. The NVEE of the lightwood areas contained increased amounts of resin acids, unsaponifiables, and acids other than fatty and resin acids. The total fatty acid content was essentially unchanged. Since fatty acid components are preferentially lost by esterification with neutral alcoholic constituents in the unsaponifiables during the distillation refining of crude tall oil, the increased unsaponifiables relative to the constant fatty acid content might result in a net reduction in fatty acid recovery from lightered trees. The turpentine content of both jack and eastern white pine increased on lightering and was primarily a mixture of ..cap alpha..- and ..beta..-pinene.

Conner, A.H.; Diehl, M.A.; Rowe, J.W.

1980-04-01

165

Too tall for the tape: the weight of schoolchildren who do not fit the Broselow tape.  

PubMed

BACKGROUND: In paediatric resuscitation, for a rapid and accurate estimate of children's weight, the Broselow tape can be used in children who are 46-144 cm tall. The Broselow tape has previously been found to provide the most accurate estimate of children's weight internationally, but it is not known how many fall outside the range of the tape, or whether such children can be assumed to be of adult weight, or how otherwise to estimate the weight of these children. OBJECTIVES: To determine what proportion of children in different age groups falls outside the limits of the Broselow tape, how their weight compares with that of the adults and what correlates most strongly with weight in these children. METHODS: This was a population-based prospective observational study of Chinese children up to 12 years old, from schools in Hong Kong. Weight was measured to the nearest 0.2 kg, and the height, foot-length and mid-arm circumference (MAC) were measured to the nearest 0.1 cm. RESULTS: 40% of 10-year olds and 70% of 11-year olds were too tall for the tape. Their median weight was 41.9 kg. This was significantly less than the median weight of 18-year olds (55 kg, p<0.0001) in Hong Kong. The strongest correlate with weight in these children was MAC. CONCLUSIONS: The Broselow tape is inappropriate for use in most children over 10 years old. Children too tall for the tape cannot be assumed to be of adult weight; to do so would imply an average overestimate of 30%. Weight estimates in older children could be based on MAC. PMID:23585576

Cattermole, G N; Leung, P Y M; Graham, C A; Rainer, T H

2013-04-13

166

Reverse engineering of TLX oncogenic transcriptional networks identifies RUNX1 as tumor suppressor in T-ALL.  

PubMed

The TLX1 and TLX3 transcription factor oncogenes have a key role in the pathogenesis of T cell acute lymphoblastic leukemia (T-ALL). Here we used reverse engineering of global transcriptional networks to decipher the oncogenic regulatory circuit controlled by TLX1 and TLX3. This systems biology analysis defined T cell leukemia homeobox 1 (TLX1) and TLX3 as master regulators of an oncogenic transcriptional circuit governing T-ALL. Notably, a network structure analysis of this hierarchical network identified RUNX1 as a key mediator of the T-ALL induced by TLX1 and TLX3 and predicted a tumor-suppressor role for RUNX1 in T cell transformation. Consistent with these results, we identified recurrent somatic loss-of-function mutations in RUNX1 in human T-ALL. Overall, these results place TLX1 and TLX3 at the top of an oncogenic transcriptional network controlling leukemia development, show the power of network analyses to identify key elements in the regulatory circuits governing human cancer and identify RUNX1 as a tumor-suppressor gene in T-ALL. PMID:22366949

Della Gatta, Giusy; Palomero, Teresa; Perez-Garcia, Arianne; Ambesi-Impiombato, Alberto; Bansal, Mukesh; Carpenter, Zachary W; De Keersmaecker, Kim; Sole, Xavier; Xu, Luyao; Paietta, Elisabeth; Racevskis, Janis; Wiernik, Peter H; Rowe, Jacob M; Meijerink, Jules P; Califano, Andrea; Ferrando, Adolfo A

2012-03-01

167

Reverse engineering of TLX oncogenic transcriptional networks identifies RUNX1 as tumor suppressor in T-ALL  

PubMed Central

The TLX1 and TLX3 transcription factor oncogenes play an important role in the pathogenesis of T-cell acute lymphoblastic leukemia (T-ALL)1,2. Here we used reverse engineering of global transcriptional networks to decipher the oncogenic regulatory circuit controlled by TLX1 and TLX3. This Systems Biology analysis defined TLX1 and TLX3 as master regulators of an oncogenic transcriptional circuit governing T-ALL. Notably, network structure analysis of this hierarchical network identified RUNX1 as an important mediator of TLX1 and TLX3 induced T-ALL, and predicted a tumor suppressor role for RUNX1 in T-cell transformation. Consistent with these results, we identified recurrent somatic loss of function mutations in RUNX1 in human T-ALL. Overall, these results place TLX1 and TLX3 atop of an oncogenic transcriptional network controlling leukemia development, demonstrate power of network analysis to identify key elements in the regulatory circuits governing human cancer and identify RUNX1 as a tumor suppressor gene in T-ALL.

Gatta, Giusy Della; Palomero, Teresa; Perez-Garcia, Arianne; Ambesi-Impiombato, Alberto; Bansal, Mukesh; Carpenter, Zachary W.; De Keersmaecker, Kim; Sole, Xavier; Xu, Luyao; Paietta, Elisabeth; Racevskis, Janis; Wiernik, Peter H; Rowe, Jacob M; Meijerink, Jules P; Califano, Andrea; Ferrando, Adolfo A.

2011-01-01

168

Baseline report - tall upland shrubland at the Rocky Flats Environmental Technology Site  

SciTech Connect

Rocky Flats Environmental Technology Site (Site) is located on the Colorado Piedmont east of the Front Range between Boulder and Golden. At an elevation of approximately 6,000 feet, the Site contains a unique ecotonal mixture of mountain and prairie plant species, resulting from the topography and close proximity to the mountain front. The Buffer Zone surrounding the Industrial Area is one of the largest remaining undeveloped areas of its kind along the Colorado Piedmont. A number of plant communities at the Site have been identified as increasingly rare and unique by Site ecologists and the Colorado Natural Heritage Program (CNHP). These include the xeric tallgrass prairie, tall upland shrubland, wetlands, and Great Plains riparian woodland communities. Many of these communities support populations of increasingly rare animals as well, including the Preble`s meadow jumping mouse, grasshopper sparrow, loggerhead shrike, Merriam`s shrew, black crowned night heron, and Hops blue and Argos skipper butterflies. One of the more interesting and important plant communities at the Site is the tall upland shrubland community. It has been generally overlooked by previous Site ecological studies, probably due to its relatively small size; only 34 acres total. Although mentioned in a plant community ordination study conducted by Clark et al. and also in the Site baseline ecological study, few data were available on this plant community before the present study.

NONE

1997-03-01

169

A Generalized Component Modal Analysis for Space Mega Frames of Super Tall Buildings  

NASA Astrophysics Data System (ADS)

A generalized component modal analytical method for space mega frames of super tall buildings is developed. The components used herein are not the actual components, but they are conceptual ones. They are actually the nodal lines employed to discretize the computational model of the structure, a three dimensional model with continuously distributed mass and stiffness. One-variable functions defined on the nodal lines selected by the analyst are unknown functions (eigenfunctions) employed to describe the behavior of the model. By a Hamiltonian principle, the governing equations of the modal analysis can be obtained, which are a set of Ordinary Differential Equations (ODE) of the eigenfunctions with their corresponding boundary conditions. The desired eigenvalues and corresponding eigenfunctions (eigenmode) can be obtained by numerically solving the system of ODEs with boundary conditions. The method is applied to the space-mega-frame system of super tall buildings. The results from the illustration example show that the method is rational and powerful for the modal analysis of space-mega-frame systems.

Gong, Yaoqing; Liu, Liping

2010-05-01

170

Interaction of heavy metals and pyrene on their fates in soil and tall fescue (Festuca arundinacea).  

PubMed

90-Day growth chamber experiments were performed to investigate the interactive effect of pyrene and heavy metals (Cu, Cd, and Pb) on the growth of tall fescue and its uptake, accumulation, and dissipation of heavy metals and pyrene. Results show that plant growth and phytomass production were impacted by the interaction of heavy metals and pyrene. They were significantly decreased with heavy metal additions (100-2000 mg/kg), but they were only slightly declined with pyrene spiked up to 100 mg/kg. The addition of a moderate dosage of pyrene (100 mg/kg) lessened heavy metal toxicity to plants, resulting in enhanced plant growth and increased metal accumulation in plant tissues, thus improving heavy metal removal by plants. In contrast, heavy metals always reduced both plant growth and pyrene dissipation in soils. The chemical forms of Cu, Cd, and Pb in plant organs varied with metal species and pyrene addition. The dissipation and mineralization of pyrene tended to decline in both planted soil and unplanted soils with the presence of heavy metals, whereas they were enhanced with planting. The results demonstrate the complex interactive effects of organic pollutants and heavy metals on phytoremediation in soils. It can be concluded that, to a certain extent, tall fescue may be useful for phytoremediation of pyrene-heavy metal-contaminated sites. Further work is needed to enhance methods for phytoremediation of heavy metal-organics co-contaminated soil. PMID:24383577

Lu, Mang; Zhang, Zhong-Zhi; Wang, Jing-Xiu; Zhang, Min; Xu, Yu-Xin; Wu, Xue-Jiao

2014-01-21

171

Influence of copper supplementation on blood and liver copper in cattle fed tall fescue or quackgrass.  

PubMed

Copper concentrations were measured in naturally Cu-deficient and Cu-supplemented yearling Hereford heifers fed tall fescue (Festuca arundinacea Schreb.) or quackgrass (Agropyron repens [L] Beauv.) forage. The data were used to establish a relationship between dietary Cu supplementation and accumulation of liver Cu, and to test the influence of diet and Cu supplementation on blood plasma Cu and ceruloplasmin oxidase activity. Dietary Cu supplementation was positively correlated with accumulation of liver Cu; the rate of increase in liver Cu levels diminished at high supplementation rates (liver Cu = 410.43 - 353.47 x e-.00295 x mg Cu supplement; R2 = .740), suggesting an efficient mechanism preventing fast, toxic Cu-overloading in cattle. The linear relationship (R2 = .7878) between blood plasma Cu and ceruloplasmin oxidase activity indicated that similar percentages of blood plasma Cu were present as ceruloplasmin in deficient, normal and Cu-supplemented cattle. However, the portion of plasma Cu occurring as ceruloplasmin changes significantly with type of feed. When compared with quackgrass, tall fescue not only produced rapid Cu depletion in unsupplemented cattle, but affected intermediary Cy metabolism and activity of Cu-enzyme ceruloplasmin differently at all levels of experimental Cu supplementation. PMID:3957807

Stoszek, M J; Mika, P G; Oldfield, J E; Weswig, P H

1986-01-01

172

Secondary flow and its stability for natural convection in tall vertical enclosures  

SciTech Connect

The multicellular flow in a tall vertical rectangular and annular enclosure was studied by solving the Boussinesq equations with time-splitting pseudospectral methods. Comparison between two time-splitting algorithms is presented, and results show that the method that introduces a time-splitting error in the calculation is unacceptable for simulations of time-dependent large Prandtl number flows. The steady flow of air and the time-periodic flow of oil were investigated, and descriptions of these flows based on physical and spectral approaches are presented. The dependency of the flow on the axial wave length was established and it was found that the maximum heat transfer appears to coincide with the natural axial wave length. Three-dimensional linear stability of the multicellular flow of air in a cartesian slot was also investigated. The domain of stable two-dimensional cellular motions was found to be constrained by the Eckhaus instability and by two types of monotone instabilities. These limit the two-dimensional multicellular flow to Grashof numbers below about 8550. For this reason the flow of air in a sufficiently tall vertical cavity is likely to be three-dimensional in many practical cases.

Chait, A.

1986-01-01

173

Meiotic and isozymic characterization of plants regenerated from euploid and selfed monosomic tall fescue embryos.  

PubMed

Tissue culture of tall fescue (Festuca arundinacea Schreb., 2n=6x=42) would be enhanced by improving the callus induction and plant regeneration efficiency, and evaluating the meiotic and isozymic variation induced by culture. Mature embryos were cultured from four lines of Kenhy tall fescue and from the progeny of three selfed monosomics. Evaluation of six media-auxin combinations showed callus initiation was greatest on SH medium with 2.5 mg/l 2,4,5-T or 7.4 mg/l pCPA, while plant regeneration was greatest on SH medium with 0.5 mg/l 2,4-D. Cytological analyses of 27 plants derived from euploid parents showed a high frequency of aneuploidy (15/27). Chromosome numbers of aneuploids ranged from 36 to 41, with one plant having 80 chromosomes and two plants being asynaptic. Two of ten monosomic-derived plants were euploid, five were monosomic, one was monosomic with a fragment and two were double monosomic. Zymograms of the parents and regenerants were obtained for the enzymes ACPH, ADH, GOT, 6-PGD and PGI. Isozyme variation was observed for two groups of plants derived from the same Kenhy embryos. One group of four monosomic-derived plants differed for the enzymes GOT and ACPH, and all four plants had a PGI pattern. different from that of the parental monosomic plant. This indicated loss of a PGI allele, probably as a result of callus culture. PMID:24226117

Dahleen, L S; Eizenga, G C

1990-01-01

174

NanoSail-D  

NASA Technical Reports Server (NTRS)

The "NanoSail-D" mission is currently scheduled for launch onboard a Falcon-1 Launch Vehicle in the early June 2008 timeframe. The NanoSail-D spacecraft will consist of a solar sail subsystem stowed in a 2U volume and a 1U spacecraft bus, provided by Ames Research Center. The primary objectives of the NanoSail-D technology demonstration mission are to fabricate, stow and deploy on-orbit a solar sail and perform a de-orbit maneuver to demonstrate a potential orbital debris mitigation technology. The NanoSail-D mission is being developed through a collaborative effort between the NASA Marshall Space Flight Center and the NASA Ames Research Center Small Spacecraft Office. Details of the NanoSail-D system will be presented, including: 1) design details of the solar sail reflective membrane quadrants, gossamer booms, deployment system and passive attitude control system, 2) design analysis results including structural, thermal, environmental, orbital debris and safety, and 3) test results including deployment, ascent venting, launch vibration and PPOD integration verification.

Montgomery, Edward E., IV; Adams, Charles L.

2008-01-01

175

What is Nano-Infusion?  

NSDL National Science Digital Library

This page from Nano-Link describes Nano-Infusion. This program "promotes integration and inclusion of nanoscale concepts into high school and college level education." Teachers are encouraged to join the free program to obtain training, support, and nano-related supplies that will aid in introducing nano experiments into their classrooms. To join the program, applicants merely need to create an account on the Nan-Link website and complete and introductory survey.

2012-11-08

176

An amperometric hydrogen peroxide biosensor based on immobilizing horseradish peroxidase to a nano-Au monolayer supported by sol–gel derived carbon ceramic electrode  

Microsoft Academic Search

A novel strategy for fabricating horseradish peroxidase (HRP)-based H2O2 sensor has been developed by combining the merits of carbon sol–gel supporting matrix and nano-scaled particulate gold (nano-Au) mediator. The thiol functional group-derived carbon ceramic electrode (CCE) was first constructed using (3-mercaptopropyl) trimethoxy silane as sol–gel monomer. Then, the stable nano-Au monolayer was obtained through covalent linkage between nano-Au and thiol

Cun-Xi Lei; Shun-Qin Hu; Na Gao; Guo-Li Shen; Ru-Qin Yu

2004-01-01

177

NANO ARTE, A POÉTICA METAFÓRICA  

Microsoft Academic Search

The text focuses on nano art as a transdisciplinary instrument for the manifestation of art, science and technology now transmuted into a poetical manifestation through the pioneer works of artist Victoria Vesna and nano scientist Jim Gimzewski viewed at the Nano: Poetry of a New World, exhibition at MAB FAAP. The evolution of microscopes is here related to the full

Anna Barros

178

Nano-carbons as theranostics.  

PubMed

Nano-carbons, including fullerenes, carbon nanoparticles, carbon nanotubes, graphene, and nano-diamonds, are an important class of nanostructures attracting tremendous interests in the past two decades. In this special issue, seven review articles and research reports are collected, to summarize and present the latest progress in the exploration of various nano-carbons for theranostic applications. PMID:22448193

Liu, Zhuang; Liang, Xing-Jie

2012-01-01

179

NANO: Network Access Neutrality Observatory  

Microsoft Academic Search

We present NANO, a system that establishes whether per- formance degradations that services or clients experience are caused by an ISP's discriminatory policies. To distin- guish discrimination from other causes of degradation (e.g., overload, misconfiguration, failure), NANO uses a statisti- cal method to estimate causal effect. NANO aggregates pas- sive measurements from end-hosts, stratifies the measure- ments to account for

Mukarram Bin Tariq; Murtaza Motiwala; Nick Feamster

180

CALM-AF10+ TALL expression profiles are characterized by overexpression of HOXA and BMI1 oncogenes  

Microsoft Academic Search

The t(10;11)(p13;q14–21) is found in T-ALL and acute myeloid leukemia and fuses CALM (Clathrin-Assembly protein-like Lymphoid-Myeloid leukaemia gene) to AF10. In order to gain insight into the transcriptional consequences of this fusion, microarray-based comparison of CALM-AF10+ vs CALM-AF10? T-ALL was performed. This analysis showed upregulation of HOXA5, HOXA9, HOXA10 and BMI1 in the CALM-AF10+ cases. Microarray results were validated by

W A Dik; W Brahim; C Braun; V Asnafi; N Dastugue; O A Bernard; J J M van Dongen; A W Langerak; E A Macintyre; E Delabesse

2005-01-01

181

Characterizing the Vertical Flux of CO2 within the Nocturnal Boundary Layer near a Tall Tower  

NASA Astrophysics Data System (ADS)

Understanding the vertical dispersion of carbon dioxide respired from plants at night is crucial to distinguishing local- to regional-scale transport and continental-scale transport in global carbon budgets. When atmospheric conditions are stable, CO2 will be weakly mixed, and nearby detectors above the surface layer will instead sample CO2 carried from large distances. These conditions often prevail during the nighttime, making that period ideal for continental-scale sampling. On the other hand, during periods of moderate or intermittent nocturnal turbulence, locally-respired CO2 will be transported through the surface layer and produce a signal at the detector. In August 2008, a 329m tall TV tower (33.4058N, 81.834W) in Aiken, South Carolina (the "South Carolina Tower" http://www.esrl.noaa.gov/gmd/ccgg/towers/#sct) was incorporated into the NOAA-Global Monitoring Division's Tall Tower network. This site is located within a region that varies from agricultural, broken forests, suburban, urban and industrial. Emissions from several cities (most notably Augusta, GA) and industrial sites are within 50km of the tower and may contribute disproportionately to the nighttime tower readings. To distinguish local and regional sources, it is necessary to characterize vertical turbulent transport at this site. There are several ways to do this, and we focus on three. First, a mesoscale model was run at high-resolution to recreate the winds and temperature observed during a May 2009 nocturnal tracer release field project conducted in the region surrounding the site. The model data then served as input to a Lagrangian transport model. This was done for two eight-hour periods on successive but different nights: one slightly stable, and the other more stable. The coupled mesoscale/transport model was then validated against the tracer data, and was used to calculate the dispersion properties of the tracer and provide a 3-dimensional picture of the plume. For comparison, we apply two other methods to calculate eddy diffusivity. We calculate it directly using sonic anemometer and fast-response CO2 flux and concentration data from the tall tower. The fast response data (10Hz) allows for the explicit calculation of the turbulent transport and, along with the vertical gradient, provide an estimate of the diffusivity. As a third method, the eddy diffusivity can also be calculated by an empirical method that uses as input the turbulent properties measured at the tower. We select one such method and compare the results to the other two estimates.

Werth, D. W.; Buckley, R.; Kurzeja, R.; Zhang, G.; Parker, M.; Duarte, H.; Leclerc, M.

2012-12-01

182

Numerical modeling of initiation of lightning leaders from tall structures by sprite-producing lightning discharges  

NASA Astrophysics Data System (ADS)

It is well established by now that large charge transfers between cloud and ground in positive cloud-to-ground lightning discharges (+CGs) can lead to transient electric field enhancements at mesospheric and lower ionospheric altitudes. In these events the electric field can exceed the conventional breakdown field and lead to formation of transient luminous events referred to as sprites and sprite halos [e.g., Qin et al., JGR, 116, A06305, 2011, and references therein]. Stanley and Heavner [Proc. 12th International Conference on Atmospheric Electricity, Versailles, France, 2003] reported that the large and rapid charge transfer of +CGs producing sprites can also initiate upward positive leaders from tall structures. These authors also presented data analysis indicating that structures with >400 m height have a significantly enhanced probability of launching upward positive leaders that may culminate in a -CG return stroke to the structure. The effect can be understood by considering the field intensification at the top of the tall structure combined with fast application of the field preventing formation and shielding effects of ion corona [Brook et al., JGR, 66, 3967, 1961]. In the present work we utilize the most recent modeling approaches developed at Penn State [e.g., Riousset et al., JGR, 115, A00E10, 2010] to quantify the conditions leading to initiation of positive leaders from tall structures following sprite-producing +CGs. Experiments show that the streamer zone transforms into leader when voltage drop along the streamer zone exceeds 400 kV [e.g., Aleksandrov et al., J. Phys. D: Appl. Phys., 38, 1225, 2005]. For a formed leader half of the voltage drops in the streamer zone, and another half in free space ahead of the streamer zone [Bazelyan and Raizer, Lightning physics and lightning protection, p. 62, 2000]. In our analysis therefore we assume that minimum voltage at the tip of the tower should exceed 800 kV for sustainment of upward propagating leader. The results indicate, in particular, that a charge moment change of 390 C km in a +CG can lead to leader initiation from a 457 m tower approximately 15 km from the +CG, in good agreement with observations reported in [Stanley and Heavner, 2003]. We report detailed relationships, including analytical estimates and numerical modeling results, providing information on the charge moment charges versus tower height and radial position with respect to +CG required for initiation of upward leaders.

Pasko, V. P.

2011-12-01

183

Are tall trees more sensitive to prolonged drought in tropical per-humid forests?  

NASA Astrophysics Data System (ADS)

Seasonality of water flux was investigated for common tree species of a Central Sulawesi pre-montane perhumid forest located in the Lore Lindu National Park. Trees were exposed to reduced soil water levels under a rainfall exclusion experiment (Sulawesi Throughfall Displacement Experiment, STD), to simulate drought effects and to monitor species-specific short-term responses to extended water stress. Several climate scenarios predict more frequent occurrence of ENSO droughts with increasing severity induced by global warming. Detailed assessments of the ecological consequences of droughts in perhumid forests are scarce and knowledge whether and how these ecosystems are adapted to severe droughts is limited. Key research questions were: (1) how do tall rainforest trees cope with long pathways under low evaporative demand, (2) how sensitive are trees from tropical perhumid forests and how do they acclimate to drought-stress and 3) does wood density determine the drought sensitivity of perhumid forest trees? From June 2007 until October 2009 we monitored 95 trees from 8 common tree species. Half of them were located under the STD Experiment and the other half in control areas. We used the constant heated method to continuously monitor stem xylem flux density and conduct parallel measurements of xylem anatomy and hydraulic conductivity in twigs, stems and roots. After almost 22 months of experimental drought only 25% of xylem flux density reduction was observed in the experimental trees. But the reaction to water stress was species-specific and in some species xylem flux went down to 50 % compared to the individuals located at the control plots. Wood density did not correlate with any hydraulic measurement, but anatomy and hydraulic architecture observations showed a positive correlation between xylem conductivity and vessel size with tree height. These results reveal a well adapted hydraulic system of tall canopy trees allowing for highly efficient water flow under conditions of low atmospheric evaporative demand at the cost of cavitation security. But this is contradictory to the low reduction in xylem flux density with drought since tall trees undergo the risk of cavitation by having large vessels. With drought these vessels should be easily embolized and we should have observed a clear reduction in xylem flux.

Schuldt, Bernhard; Horna, Viviana; Leuschner, Christoph

2010-05-01

184

Nano Ice Cream  

NSDL National Science Digital Library

In this activity/demo, learners discover how liquid nitrogen cools a creamy mixture at such a rapid rate that it precipitates super fine grained (nano) ice cream. This is a fun (and tasty!) way for learners to discover the nanoworld! Note: this activity should be conducted by adults only.

Network, Nanoscale I.; Science, Museum O.

2014-06-04

185

Nano Meets Spectroscopy  

Microsoft Academic Search

The multidisciplinary two-day Nano Meets Spectroscopy (NMS) event was held at the National Physical Laboratory (NPL), Teddington, UK, in September 2011. The event was planned from the outset to be at the interface of several areas—in particular, spectroscopy and nanoscience, and to bring together topics and people with different approaches to achieving common goals in biomolecular science. Hence the meeting

David J S Birch

2012-01-01

186

Parallel Computations of Natural Convection Flow in a Tall Cavity Using an Explicit Finite Element Method  

SciTech Connect

The Galerkin Finite Element Method was used to predict a natural convection flow in an enclosed cavity. The problem considered was a differentially heated, tall (8:1), rectangular cavity with a Rayleigh number of 3.4 x 10{sup 5} and Prandtl number of 0.71. The incompressible Navier-Stokes equations were solved using a Boussinesq approximation for the buoyancy force. The algorithm was developed for efficient use on massively parallel computer systems. Emphasis was on time-accurate simulations. It was found that the average temperature and velocity values can be captured with a relatively coarse grid, while the oscillation amplitude and period appear to be grid sensitive and require a refined computation.

Dunn, T.A.; McCallen, R.C.

2000-10-17

187

The analysis of the effects of frame response on basement shelters in tall buildings. Final report  

SciTech Connect

This report presents the results of a program to develop a theoretical analysis of the effects of frame response on basement shelters in tall buildings. The objective was to determine the effect on an upgraded basement key worker shelter of the aboveground portion of the structure being subjected to a blast wave that would destroy the building. Both steel and reinforced concrete frame structures were investigated, with most emphasis on poured-in-place reinforced concrete beam, slab, and girder type framing and poured-in-place flat-slab and flat-plate construction. A prediction technique usng both hand and computer analysis was developed and tested using a previously demolished 15-story cast-in-place reinforced structure. The analysis indicated that the upgraded basement would have survived even through the aboveground portion of the structure was exposed to 50 psi.

Gabrielsen, B.L.; Cuzner, G.J.; Hendricks, J.; Zsutty, T.C.

1982-10-01

188

Nano-Satellite Avionics  

NASA Technical Reports Server (NTRS)

Abstract NASA's Goddard Space Flight Center (GSFC) is currently developing a new class of satellites called the nano-satellite (nano-sat). A major objective of this development effort is to provide the technology required to enable a constellation of tens to hundreds of nano-satellites to make both remote and in-situ measurements from space. The Nano-sat will be a spacecraft weighing a maximum of 10 kg, including the propellant mass, and producing at least 5 Watts of power to operate the spacecraft. The electronics are required to survive a total radiation dose rate of 100 krads for a mission lifetime of two years. There are many unique challenges that must be met in order to develop the avionics for such a spacecraft. The first challenge is to develop an architecture that will operate on the allotted 5 Watts and meet the diverging requirements of multiple missions. This architecture will need to incorporate a multitude of new advanced microelectronic technologies. The microelectronics developed must be a modular and scalable packaging of technology to solve the problem of developing a solution to both reduce cost and meet the requirements of various missions. This development will utilize the most cost effective approach, whether infusing commercially driven semiconductor devices into spacecraft applications or partnering with industry to design and develop low cost, low power, low mass, and high capacity data processing devices. This paper will discuss the nano-sat architecture and the major technologies that will be developed. The major technologies that will be covered include: (1) Light weight Low Power Electronics Packaging, (2) Radiation Hard/Tolerant, Low Power Processing Platforms, (3) High capacity Low Power Memory Systems (4) Radiation Hard reconfiguragble field programmable gate array (rFPGA)

Culver, Harry

1999-01-01

189

Promoting late-fall establishment of tall fescue with artificial soil covers to minimise soil erosion.  

PubMed

Frequently, turfgrass seedings have been sown in the late fall, which usually results in a poor vegetative stand and the possibility of soil erosion the following spring. This study evaluates the effects of a spun-bonded polyester soil cover placed over a late-fall seeding on subsequent seedling growth and overwintering. Clemfine, Mustang, Rebel, and Rebel II cultivars of tall fescue (Festuca arundinacea Schreb.) were sown on a silt loam soil in late fall (on 17 October in 1989 and 19 October in 1990) and allowed to grow with and without a soil cover until June. In the spring the temperature under the soil cover was greater than 2°C warmer than the uncovered soil from mid-April through May. Over the winter, leaf and root weights showed no detrimental effects from being under the cover. Individual cultivars grown under the cover produced 2 to 11 times greater leaf yields and 38 to 270% better stand establishment than those sown on the exposed soil. However, plant winter injury was observed under the soil cover in small soil depressions which accumulated water originating from thawing. All cultivars had similar amounts of growth under the cover. However, leaf yields for Rebel were 30-55% less than the other cultivars when grown under the cover and this was probably related to a low seed germination rate. The covers also promoted weed growth, which comprised from 34-65% of total leaf weights and was found to be negatively correlated (r = -0.66) to the yields of the sown grass. The soil cover was found to be beneficial to improving the success of seedling establishment of late seedings of tall fescue in cold areas. PMID:24198171

Palazzo, A J

1994-03-01

190

Recent Results From the NOAA/ESRL GMD Tall Tower Network  

NASA Astrophysics Data System (ADS)

We will present a summary of new results from NOAA Earth System Research Laboratory`s Tall Tower greenhouse gas monitoring network. The tower network is operated by the Global Monitoring Division, which also maintains the global Cooperative Air Sampling network and a network of aircraft profiling sites over North America. Tall tower CO2 mixing ratio measurements are sensitive to upwind fluxes over scales of hundreds of kilometers, and the primary objective of the tower network is to obtain regionally representative carbon flux estimates for the North American continent. Mixing ratios of CO2 and CO are measured semi-continuously at the towers, and the KWKT-TV tower site near Moody, TX has recently also been equipped with sensors to measure radon and O3. Daily flask samples are collected at the KWKT tower and analyzed for CO2, CO, CH4, SF6, N2O, H2, stable isotopes of CO2 and CH4, COS, and a variety of halocarbon and hydrocarbon species. Daily flask sampling will be implemented at all tower sites within the next few years. We have used the Stochastic Time Inverted Lagrangian Transport (STILT) model to investigate upwind influences on the tower observations. CO measurements provide an indicator of polluted air masses, and we will present a summary of the frequency and origin of pollution events observed at the towers. We will present an analysis of the primary factors contributing to observed CO2 variability along with average seasonal and diurnal cycles of CO2 at the tower sites. Tower measurements are being used to evaluate atmospheric transport models in the context of the Transcom Continuous experiment and are an important constraint for CO2 data assimilation systems that produce regional to global carbon flux estimates with up to weekly resolution.

Andrews, A. E.; Tans, P. P.; Peters, W.; Hirsch, A.; Sweeney, C.; Petron, G.; Kofler, J.; Zhao, C.; Masarie, K.; Wofsy, S. C.; Matross, D. M.; Mahadevan, P.; Longo, M.; Gerbig, C.; Lin, J. C.

2006-12-01

191

Urinary and Biliary Excretion of Ergot Alkaloids from Steers That Grazed Endophyte-Infected Tall Fescue1  

Microsoft Academic Search

Ergot alkaloids cause fescue toxicosis when livestock graze endophyte-infected (E+) tall fescue. Little is known about the bioavailability of the ergot alkaloid classes (lysergic acid, lysergic acid amides, or ergopeptine alkaloids) in livestock, and this hampers development of pharmacological strate- gies to ameliorate the toxicosis. One method used to determine bioavailability of ergot alkaloids is to examine urinary and biliary

J. A. Stuedemann; N. S. Hill; F. N. Thompson; R. A. Fayrer-Hosken; W. P. Hay; D. L. Dawe; D. H. Seman; S. A. Martin

2010-01-01

192

78 FR 54574 - Safety Zone; Tall Ships Erie 2013 Fireworks Show, Holland Street Pier, Presque Isle Bay, Erie, PA  

Federal Register 2010, 2011, 2012, 2013

...Street Pier, Presque Isle Bay, Erie, PA AGENCY: Coast Guard...safety zone on Presque Isle Bay, Erie, PA. This safety zone is intended...Isle Bay during the Tall Ships Erie 2013 Fireworks Show. This temporary...Temporary Final Rule A. Regulatory History and Information The Coast...

2013-09-05

193

THE COLONIZATION AND FORMATION OF EQUILIBRIUM PLANT SPECIES ASSOCIATIONS ON BADGER DISTURBANCES IN A TALL-GRASS PRAIRIE  

Microsoft Academic Search

Badger disturbances in a tall-grass prairie were used to study colonization patterns and the formation of equilibrium plant species associations in a complex mainland community. Colonization processes were described from field observations over a 4-yr period. A qualitative colonization model was developed to predict noninteractive species equilibria. Predicted colonization rates were based upon relative immigration rates determined by interactions among

WILLIAM J. PLATT

1975-01-01

194

Auxin-gibberellin interaction in apical dominance: Experiments with tall and dwarf varieties of pea and bean  

Microsoft Academic Search

Seedlings of dwarf and tall varieties of pea and bean, growing in John Innes Compost No. 2, were studied in relation to the effects of decapitation, indole-3-acetic acid (IAA), and gibberellic acid (GA3) on axillary bud growth. In all varieties, GA3 antagonized the inhibitory influence of IAA on bud growth when both hormones were applied to the upper cut end

I. D. J. Phillips

1969-01-01

195

46 CFR 34.20-90 - Installations contracted for prior to January 1, 1970-T/ALL.  

Code of Federal Regulations, 2013 CFR

...Installations contracted for prior to January 1, 1970-T/ALL. 34.20-90 Section 34...Installations contracted for prior to January 1, 1970âT/ALL. (a) Installations contracted for prior to January 1, 1970, shall meet the following...

2013-10-01

196

46 CFR 32.40-65 - Crew accommodations on tankships constructed before June 15, 1987-T/ALL.  

Code of Federal Regulations, 2013 CFR

...accommodations on tankships constructed before June 15, 1987-T/ALL. 32.40-65 Section 32.40-65 Shipping COAST...accommodations on tankships constructed before June 15, 1987âT/ALL. All tankships of 100 gross tons and over...

2013-10-01

197

46 CFR 34.10-90 - Installations contracted for prior to May 26, 1965-T/ALL.  

Code of Federal Regulations, 2013 CFR

... false Installations contracted for prior to May 26, 1965-T/ALL. 34.10-90 Section 34.10-90 Shipping COAST...10-90 Installations contracted for prior to May 26, 1965âT/ALL. (a) Installations contracted for prior to...

2013-10-01

198

46 CFR 34.17-90 - Installations contracted for prior to January 1, 1962-T/ALL.  

Code of Federal Regulations, 2013 CFR

...false Installations contracted for prior to January 1, 1962-T/ALL. 34.17-90 Section 34.17-90 Shipping COAST...17-90 Installations contracted for prior to January 1, 1962âT/ALL. (a) Installations contracted for prior to...

2013-10-01

199

ESTIMATION OF DIGESTA KINETICS OF FORAGE KOCHIA AND TALL WHEATGRASS USING YB AND DY WHEN FED ALONE OR MIXED TOGETHER  

Microsoft Academic Search

Little is known about the nutritional value of forage kochia (Kochia prostrata) for grazing beef cattle when mixed in low-quality forage diets. Our objectives were to evaluate digesta kinetics using different ratios of forage kochia and tall wheatgrass (Agropyron elongatum) and to examine the use of two rare earth markers to simultaneously measure the kinetics of each feedstuff. Five ruminally

A. R. Wall; K. C. Olson; C. A. Stonecipher; M. Stuart; M. A. Maughn; J. C. Malechek

200

Wet concrete loading of thin-walled steel box columns during the construction of a tall building  

Microsoft Academic Search

Concrete filled thin-walled steel box columns are currently being increasingly used in the construction and design of tall buildings. These columns provide economy during construction and many other advantages for steel-framed buildings. The most significant factor that concrete filled steel box columns display in reducing the construction cost of a steel framed building is that the external steel box provides

B. Uy; S. Das

1997-01-01

201

Effects of Ozone on the Regrowth and Energy Reserves of a Ladino Clover-Tall Fescue Pasture.  

National Technical Information Service (NTIS)

A ladino clover and tall fescue pasture was established in September 1983 to determine the impact of ozone and available soil moisture on plants grown in open-top field chambers and exposed for 12 h daily to ozone (O3) from April through October in 1984 a...

J. Rebbeck U. Blum A. S. Heagle

1988-01-01

202

Pollen-mediated transgene flow in the wind-pollinated grass species tall fescue ( Festuca arundinacea Schreb.)  

Microsoft Academic Search

Information regarding gene flow in wind-pollinated, outcrossing forage grasses is essential for any future releases of value-added transgenic cultivars. Experiments on pollen dispersal was carried out by growing transgenic tall fescue (Festuca arundinacea) in a central plot, surrounded by exclosures containing recipient plants up to a distance of 200 m from the central source plants in eight directions. The central

Z. Y. Wang; R. Lawrence; A. Hopkins; J. Bell; M. Scott

2004-01-01

203

40 CFR 721.10188 - Fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine...  

Code of Federal Regulations, 2010 CFR

. (1) The chemical substance identified generically as fatty acids, tall-oil, reaction products with 4-methyl-2-pentanone and aliphatic polyamine (PMN P-05-186, Chemical B) is subject to reporting under this section for the significant new uses described in paragraph (a)(2) of this...

2010-07-01

204

Tall oatgrass mosaic virus (TOgMV): a novel member of the genus Tritimovirus infecting Arrhenatherum elatius.  

PubMed

A novel tritimovirus of the family Potyviridae was isolated from tall oatgrass, Arrhenatherum elatius, exhibiting mosaic symptoms. The virus, for which the name tall oatgrass mosaic virus (TOgMV) is coined, has a filamentous particle of 720 nm and is associated with pinwheel inclusion bodies characteristic of members of the family Potyviridae. The virus was mechanically transmitted to tall oatgrass seedlings, which subsequently exhibited mosaic symptoms. The experimental host range was limited to a few monocot species. The complete genome sequence of TOgMV was determined to be 9359 nucleotides, excluding the 3' polyadenylated tail. The viral RNA encodes one large putative open reading frame of 3029 amino acids with a genome organization typical of monopartite potyvirids. Pairwise comparison of putative mature proteins and proteinase cleavage sites indicated that TOgMV is most closely related to members of the genus Tritimovirus. Phylogenetic analysis of the complete polyprotein and CP sequences of representative members of the family Potyviridae indicate that TOgMV is a distinct tritimovirus naturally infecting tall oatgrass. PMID:24193952

Hassan, Mohamed; Sirlová, Lenka; Vacke, Josef

2014-07-01

205

FePt Nano-particles and Nano -wires  

NASA Astrophysics Data System (ADS)

In this work, we have studied the microstructure and magnetic properties of FePt nano-particles, nano-rods, and nano-wires synthesized by a modified chemical synthesis route described elsewhere^[1],[2] The effect of synthesis parameters on the particle shape has been investigated for nanoparticles with sizes of 5-7 nm, for nano-rods and nano-wires with a diameter of 2-3 nm and a length of 20 and 100 nm, respectively. Low injection temperature for the iron precursor and usage of surfactants as reaction solvents resulted in 7 nm nano-cubes whereas a high heating rate to refluxing temperature and high injection temperature resulted in spherical shapes with 5 nm diameter. Nano-rods and nano-wires are formed by simply adjusting the relative ratios of surfactants to reaction solvents (oleic acid, oleyl amine and octadecene/benzylether) and the refluxing time. Transmission electron microscope (TEM) studies show that usage of high concentrations of oleyl amine and longer refluxing times induce nano-wire formation. HRTEM and magnetometry studies are currently in progress to investigate the development of particle morphology and microstructure during the synthesis and determine their influence on the magnetic properties. 1. C.Wang et. al. Angew. Chem. Int. Ed. 2007, 46,1-4. 2. M. Chen et. al. J. Am. Chem. Soc. 2007, 129, 6348-6349.

Colak, Levent; Hadjipanayis, George

2008-03-01

206

Protein micro- and nano-capsules for biomedical applications.  

PubMed

Micro- and nano-scale systems have emerged as important tools for developing clinically useful drug delivery systems. In this tutorial review, we discuss the exploitation of biomacromolecules for this purpose, focusing on proteins, polypeptides, nucleic acids and polysaccharides and mixtures thereof as potential building blocks for novel drug delivery systems. We focus on the mechanisms of formation of micro- and nano-scale protein-based capsules and shells, as well as on the functionalization of such structures for use in targeted delivery of bioactive materials. We summarise existing methods for protein-based capsule synthesis and functionalization and highlight future challenges and opportunities for delivery strategies based on biomacromolecules. PMID:24336689

Shimanovich, Ulyana; Bernardes, Gonçalo J L; Knowles, T P J; Cavaco-Paulo, Artur

2014-03-01

207

Novel approaches to biosensing and nano-biological interactions  

NASA Astrophysics Data System (ADS)

Nanotechnology has recently been applied to a wide range of biological systems. In particular, there is a current push to examine the interface between the biological world and micro/nano-scale systems. Our research in this field has led to the development of novel strategies for spatial patterning of biomolecules, electrical and optical biosensing, nanomaterial delivery systems, single-cell manipulation, and the study of cellular interactions with nano-structured surfaces. Current work on these topics will be presented, including work on novel, semiconductor-based DNA detection methods and mechanical, atomic force microscopy (AFM)-based characterization of bacterial biofilms in threedimensional microfluidic systems.

Cady, Nathaniel C.; Fahrenkopf, Nicholas; Mosier, Aaron

2009-08-01

208

Coupled nano-plasmons  

NASA Astrophysics Data System (ADS)

A simple model of coupled plasmons arising in two neighbouring nano-particles is presented. The coupled oscillations and the corresponding eigenfrequencies are computed. It is shown that the plasmons may be periodically transferred between the two particles. For larger separation distances between the two particles the retardation is included. The oscillation eigenmodes are the polaritons in this case. There are distances for which the particles do not couple to each other, i.e. the polaritonic coupling gets damped. The van der Waals-London-Casimir force is estimated for the two particles; it is shown that for large distances the force is repulsive. We compute also the polarizabilities of the two coupled nano-particles and their cross-section under the action of an external monochromatic plane wave, which exhibit resonances indicative of light trapping and field enhancement. A resonant force is also identified, acting upon the particles both on behalf of the external field and of each other.

Apostol, M.; Ilie, S.; Petrut, A.; Savu, M.; Toba, S.

2014-05-01

209

Measurement of property relationships of nano-structure micelles and coacervates of asphaltene in a pure solvent  

Microsoft Academic Search

We have made some progress in studies towards formation and measurement of the behavior of asphaltene micelles nano-structures that might be formed to serve as elements of nano-materials and also on synthetic strategies for creating such structures. An investigation of the micellization and coacervation measurements of asphaltenes in polar solvents at various concentrations and temperatures are made. The critical micellization

Slamet Priyanto; G. Ali Mansoori; Aryadi Suwono

2001-01-01

210

Transcriptional Activation of Prostate Specific Homeobox Gene NKX3-1 in Subsets of T-Cell Lymphoblastic Leukemia (T-ALL)  

PubMed Central

Homeobox genes encode transcription factors impacting key developmental processes including embryogenesis, organogenesis, and cell differentiation. Reflecting their tight transcriptional control, homeobox genes are often embedded in large non-coding, cis-regulatory regions, containing tissue specific elements. In T-cell acute lymphoblastic leukemia (T-ALL) homeobox genes are frequently deregulated by chromosomal aberrations, notably translocations adding T-cell specific activatory elements. NKX3-1 is a prostate specific homeobox gene activated in T-ALL patients expressing oncogenic TAL1 or displaying immature T-cell characteristics. After investigating regulation of NKX3-1 in primary cells and cell lines, we report its ectopic expression in T-ALL cells independent of chromosomal rearrangements. Using siRNAs and expression profiling, we exploited NKX3-1 positive T-ALL cell lines as tools to investigate aberrant activatory mechanisms. Our data confirmed NKX3-1 activation by TAL1/GATA3/LMO and identified LYL1 as an alternative activator in immature T-ALL cells devoid of GATA3. Moreover, we showed that NKX3-1 is directly activated by early T-cell homeodomain factor MSX2. These activators were regulated by MLL and/or by IL7-, BMP4- and IGF2-signalling. Finally, we demonstrated homeobox gene SIX6 as a direct leukemic target of NKX3-1 in T-ALL. In conclusion, we identified three major mechanisms of NKX3-1 regulation in T-ALL cell lines which are represented by activators TAL1, LYL1 and MSX2, corresponding to particular T-ALL subtypes described in patients. These results may contribute to the understanding of leukemic transcriptional networks underlying disturbed T-cell differentiation in T-ALL.

Nagel, Stefan; Ehrentraut, Stefan; Tomasch, Jurgen; Lienenklaus, Stefan; Schneider, Bjorn; Geffers, Robert; Meyer, Corinna; Kaufmann, Maren; Drexler, Hans G.; MacLeod, Roderick A. F.

2012-01-01

211

Electrospray neutralization process and apparatus for generation of nano-aerosol and nano-structured materials  

SciTech Connect

The claimed invention describes methods and apparatuses for manufacturing nano-aerosols and nano-structured materials based on the neutralization of charged electrosprayed products with oppositely charged electrosprayed products. Electrosprayed products include molecular ions, nano-clusters and nano-fibers. Nano-aerosols can be generated when neutralization occurs in the gas phase. Neutralization of electrospan nano-fibers with molecular ions and charged nano-clusters may result in the formation of fibrous aerosols or free nano-mats. Nano-mats can also be produced on a suitable substrate, forming efficient nano-filters.

Bailey, Charles L. (Cross Junction, VA); Morozov, Victor (Manassas, VA); Vsevolodov, Nikolai N. (Kensington, MD)

2010-08-17

212

Steer responses to feeding soybean hulls and steroid hormone implantation on toxic tall fescue pasture.  

PubMed

Crossbred steers were grazed in the spring and early summer on endophyte-infected (Neotyphodium coenophialum), Kentucky-31 tall fescue (Lolium arundinaceum) pastures to evaluate effects and interactions of feeding pelleted soybean hulls (PSBH) and steroid hormone implants (SHI) on steer performance, serum prolactin, and hair coat ratings (HCR). Steers were stratified by BW for assignment to six 3.0-ha toxic tall fescue pastures. With or without daily PSBH feeding, treatments were assigned randomly to pastures as the main plot treatment in a split-plot design. Pelleted soybean hulls were group-fed to provide 2.3 kg(steer·d(-1)) (as fed). With or without SHI (200 mg of progesterone and 20 mg of estradiol) treatments were randomly assigned as the subplot treatment to 2 steer subgroups within each pasture. Sixty-four steers were grazed for 77 d in 2007, and 60 steers were grazed for 86 d in 2008. Pasture forage mass declined linearly over time, but the rate of decline was greater (P = 0.001) in 2007 than in 2008. Pasture forage mass was never below 2,300 kg of DM/ha in either year. Average daily gain for steers on the combined PSBH and SHI treatments was greater (P < 0.01) than for those on the PSBH-only, SHI-only, and control (no SHI, no PSBH) treatments. Average daily gain for the PSBH-only steers was greater (P < 0.01) than for SHI-only and control steers and tended (P = 0.063) to be greater for SHI-only than for control steers. Steroid implants did not affect (P = 0.826) serum prolactin concentrations; however, prolactin concentrations in PSBH steers, with or without SHI, were increased (P = 0.01) 2-fold over SHI-only and control steers. Feeding PSBH and SHI treatments both reduced (P < 0.05) the percentage of steers with rough HCR, and a greater percentage of steers fed PSBH tended (P < 0.076) to have sleek hair coats. An economic analysis was conducted, which determined that costs of additional ADG with PSBH feeding were below breakeven costs over a wide range of PSBH costs and cattle prices. Breakeven costs for PSBH-only treatment for a range of cattle prices of $1.80 to $2.40/kg of BW were less than $120/t, whereas with PSBH feeding combined with SHI the breakeven cost was less than $240/t. Results indicate that steers grazing endophyte-infected tall fescue can be fed PSBH and implanted with steroid hormones to cost effectively increase ADG and that feeding PSBH can increase serum prolactin concentrations and induce some shedding of rough hair coats. PMID:20656966

Carter, J M; Aiken, G E; Dougherty, C T; Schrick, F N

2010-11-01

213

Nano robots in Bio medical application  

Microsoft Academic Search

Nano-robots are the robots that are simply known as that controllable machines at the nano (10?9) meter or molecular scale, composed of nano-components. More specifically, nano robotics refer to the still largely hypothetical nanotechnology engineering discipline of designing and building nano robots. Even though the field of nano robotics is fundamentally different from that of the macro robots due to

R. B. Durairaj; M. Sivasankar

2012-01-01

214

Tasco-Forage: I. Influence of a seaweed extract on antioxidant activity in tall fescue and in ruminants.  

PubMed

Seaweed (Ascophyllum nodosum) is a known source of plant growth regulators, and application to turfgrasses has increased activity of the antioxidant superoxide dismutase (SOD) and specific vitamin precursors. Increased antioxidant activity in both plants and animals diminishes oxidative stress. Two pasture experiments investigated effects of Tasco-Forage (a proprietary seaweed-based product) applied to tall fescue (Festuca arundinacea) on antioxidant activity in plants and in ruminants that grazed the forage. In Exp. 1, fescue was 70 to 100% infected with the endophyte fungus Neotyphodium coenophialum ([Morgan-Jones and Gams] Glenn, Bacon, and Hanlin). Twenty-four wether lambs (initial BW 41 kg; SD = 5) grazed fescue treated with 0, 1.7, or 3.4 kg Tasco/ha applied in April and July, 1994, with four replications per treatment. Grazing occurred for 26 d beginning April 21 and for 22 d beginning July 19. In July, there was a linear increase in daily gains (P < 0.05), and serum vitamin A (P < 0.13) and whole-blood Se (P < 0.10) tended to increase in lambs grazing Tasco-treated fescue. In Exp. 2,48 Angus and Angus x Hereford steers (initial BW 245 kg; SD = 20) grazed infected or uninfected tall fescue in Virginia that was treated (3.4 kg/ ha) or untreated with Tasco in April and July, 1995. Steers that grazed infected tall fescue had lower (P < 0.02) serum vitamin A and E and tended (P < 0.07) to have lower whole-blood Se in September compared with steers that grazed uninfected tall fescue. Tasco decreased (P < 0.06) serum vitamin E but tended to increase whole-blood Se (P < 0.10) in September and serum vitamin A in July (P < 0.12). During 1996 and 1997, the experiment was repeated in Virginia with Angus steers and was replicated at Prairie, MS, where 1/4 Brahman x 3/4 Angus steers were used. Forty-eight steers were included at each location in each year (n = 192 total steers for 1996 and 1997). Steers that grazed infected tall fescue in Mississippi had lower (P < 0.05) serum vitamin E by the end of the grazing season. At both locations Tasco increased (P < 0.05) activity of superoxide dismutase in both infected and uninfected fescue. The endophyte in tall fescue seemed to decrease antioxidant activity in grazing steers, whereas Tasco seemed to increase antioxidant activity in both the forage and the grazing ruminant. Tasco may provide opportunities to reduce oxidative stress in plants and animals. PMID:11325175

Fike, J H; Allen, V G; Schmidt, R E; Zhang, X; Fontenot, J P; Bagley, C P; Ivy, R L; Evans, R R; Coelho, R W; Wester, D B

2001-04-01

215

The TCR ?? repertoire and relative gene expression characteristics of T-ALL cases with biclonal malignant V?1 and V?2 T cells.  

PubMed

Despite significant improvement in our understanding of T-cell acute lymphoblastic leukemia (T-ALL) biology and pathogenesis, many questions remain unanswered. In previous studies, we found a T-ALL case with two malignant T-cell clones with V?1D?2D?3J?1 and V?2D?3J?2 rearrangements. In this study, we further characterized T-ALL cases with two malignant clones containing V?1D?3J?1 and V?2D?1J?1 rearrangements using fine-tiling array comparative genomic hybridization, ligation-mediated polymerase chain reaction (LM-PCR), sequencing, and reverse transcription polymerase chain reaction (RT-PCR) analysis. We further analyzed the distribution and clonality of the T-cell receptor (TCR) V? and V? subfamily T cells in the two T-ALL cases by RT-PCR and GeneScan. Monoclonal V?1 and V?2 subfamilies were confirmed in both samples, the V?3 through V?7 subfamilies could not be detected in the T-ALL samples, whereas the oligoclonal V?8 subfamily could be identified. Based on the clinical finding that both of the T-ALL cases with two malignant T-cell clones had a poor outcome, we attempted to compare the expression pattern of genes related to T-cell activation and proliferation between cases with the malignant V?1 and V?2 T-cell clones and T-ALL cases with a mono-malignant V? T-cell clone. We selected two T-ALL cases with V?J? rearrangements and analyzed the expression level of Notch1, TAL1, and the CARMA-BCL10-MALT-A20-NF-?B pathway genes by real-time PCR. A20 had significantly higher expression in the biclonal compared with the monoclonal T-ALL group (p=0.0354), and there was a trend toward higher expression for the other genes in the biclonal group with the exception of TAL1, although the differences were not statistically significant. In conclusion, we identified two T-ALL cases with biclonal malignant T-cell clones and described the characteristics of the biclonal T-ALL subtype and its gene expression pattern. Thus, our findings may improve the understanding of biclonal T-ALL. PMID:24329526

Zheng, Haitao; Wang, Xu; Ma, Yu; Xu, Bing; Chen, Shaohua; Yang, Lijian; Wu, Xiuli; Przybylski, Grzegorz K; Huang, Suming; Ye, Tiezhen; Li, Yangqiu

2014-01-01

216

A novel method for measuring trace gas fluxes from tall vegetation  

NASA Astrophysics Data System (ADS)

The nature of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) as greenhouse gases (GHGs) means that accurate measurement of their net ecosystem exchange (NEE) is extremely important to our ability to manage climate change. Manual static chambers are commonly used to measure soil fluxes of these trace gases, with landscape values extrapolated from point measurements of typically less than 1m2, at a weekly or monthly frequency. Moreover, due to the reliance upon manual sampling, data are typically biased towards day-time measurements, and use of opaque chambers halts photosynthesis. Automation of chambers, such as the Licor Li-8100 (Lincoln, NE) system, allows for measurement of soil respiration at a near-constant frequency, but does not solve the problem of measuring CH4 and N2O, neither does it allow measurements to be taken from over tall (more than 20 cm) vegetation. Eddy covariance (EC) techniques allow for high frequency measurements of CO2 and CH4 to be made at the landscape scale, and are increasingly available for N2O. However, the inability of EC to resolve to the plot scale hinders its use for manipulative experiments, and replication is rare. Additionally, stratification of the boundary layer creates difficulty in measuring night-time fluxes and it is common to discard large parts of data sets due to unsuitable wind direction or other meteorological conditions. Here we present a new technique for measuring trace gas fluxes from over tall vegetation. The system is capable of simultaneously delivering NEE of CO2, CH4 and N2O, automatically measuring at high temporal resolution (circa hourly) from replicated plots. We show the effect of green compost addition on trace gas fluxes from Miscanthus x giganteus, an important crop for bioenergy production. The ability to quantify NEE of GHGs from such crops forms an essential part of the lifecycle analysis of energy produced from biomass, which may play an important role in future mitigation of climate change.

Keane, James; Phil, Ineson

2014-05-01

217

The stable isotopic composition of atmospheric molecular hydrogen at the Cabauw tall tower in the Netherlands  

NASA Astrophysics Data System (ADS)

Molecular hydrogen (H2) is a promising energy carrier that might replace fossil fuels in vehicles. It has great potential for making transportation more sustainable, but there may be environmental side effects that, to some degree, offset the benefits. Concerns have been raised that large-scale leakage of H2 into the atmosphere could affect the atmosphere's oxidative capacity and stratospheric ozone chemistry. To assess these risks, a better understanding of the global, regional and global atmospheric H2 cycle is needed. Since the H2 source and sink processes have large effects on ?D(H2), due to the large relative mass difference between 'ordinary' hydrogen and deuterium, studying the stable isotopic composition of H2 (?D(H2)) is a promising way to achieve this. Over the last decade, studies of the isotope effects in H2 source and sink processes have appeared, ?D(H2) has been incorporated into global chemical transport models and many more environmental observations of ?D(H2) have been published. The latter, however, were mostly obtained from samples that were collected at ground level at remote locations, which is not sufficient to fully characterize the H2 cycle or to assess the possible environmental effects of H2 leakage in very polluted regions. For this project, samples are collected at the Cabauw tall tower owned by KNMI. The Cabauw tower is 213 m tall and located in a central part of the Netherlands. It is equipped with a tubing system with air inlets at 20, 60, 120, and 200 meter altitude. This tubing system was used to make continuous measurements of carbon monoxide (CO) and H2 mixing ratios, but also to collect flasks samples at different heights for the analysis of ?D(H2). More than 200 samples were collected over a period of more than three years. The results show that the local H2 cycle at Cabauw is under heavy anthropogenic influence compared to Mace Head, a station that receives mostly clean marine background air at the Irish West Coast. On average, m(H2) is larger and ?D(H2) lower at Cabauw, a result of anthropogenic emissions of deuterium-depleted H2. Because of the same anthropogenic emissions, the samples collected from the lower levels of the tower tend to have larger m(H2) and lower ?D(H2) than the samples collected from the higher levels. This also indicates that the local uptake of H2 by soils is relatively weak.

Batenburg, A. M.; Popa, M. E.; Vermeulen, A. T.; van den Bulk, W. C. M.; Jongejan, P. A. C.; Röckmann, T.

2012-04-01

218

Genotoxic effects of fumes from asphalt modified with waste plastic and tall oil pitch.  

PubMed

As the use of recycled materials and industrial by-products in asphalt mixtures is increasing, we investigated if recycled additives modify the genotoxicity of fumes emitted from asphalt. Fumes were generated in the laboratory at paving temperature from stone-mastic asphalt (SMA) and from SMA modified with waste plastic (90% polyethylene, 10% polypropylene) and tall oil pitch (SMA-WPT). In addition, fumes from SMA, SMA-WPT, asphalt concrete (AC), and AC modified with waste plastic and tall oil pitch (AC-WPT) were collected at paving sites. The genotoxicity of the fumes was studied by analysis of DNA damage (measured in the comet assay) and micronucleus formation in human bronchial epithelial BEAS 2B cells in vitro and by counting mutations in Salmonella typhimurium strains TA98 and YG1024. DNA damage was also assessed in buccal leukocytes from road pavers before and after working with SMA, SMA-WPT, AC, and AC-WPT. The chemical composition of the emissions was analysed by gas chromatography/mass spectrometry. The SMA-WPT fume generated in the laboratory induced a clear increase in DNA damage in BEAS 2B cells without metabolic activation. The laboratory-generated SMA fume increased the frequency of micronucleated BEAS 2B cells without metabolic activation. None of the asphalt fumes collected at the paving sites produced DNA damage with or without metabolic activation. Fumes from SMA and SMA-WPT from the paving sites increased micronucleus frequency without metabolic activation. None of the asphalt fumes studied showed mutagenic activity in Salmonella. No statistically significant differences in DNA damage in buccal leukocytes were detected between the pre- and post-shift samples collected from the road pavers. However, a positive correlation was found between DNA damage and the urinary metabolites of polycyclic aromatic hydrocarbons (PAHs) after work shift, which suggested an association between occupational exposures during road paving and genotoxic effects. Our results indicate that fumes from SMA and SMA-WPT contain direct-acting genotoxic components. PMID:18499510

Lindberg, Hanna K; Väänänen, Virpi; Järventaus, Hilkka; Suhonen, Satu; Nygren, Jonas; Hämeilä, Mervi; Valtonen, Jarkko; Heikkilä, Pirjo; Norppa, Hannu

2008-05-31

219

Magnetic Nano-Materials: Truly Sustainable Green Chemistry Nano Catalysis  

EPA Science Inventory

We envisioned a novel nano-catalyst system, which can bridge the homogenous and heterogeneous system, and simultaneously be cheaper, easily accessible (sustainable) and possibly does not require elaborate work-up. Because of its nano-size, i.e. high surface area, the contact betw...

220

Laser-induced breakdown spectroscopy used to detect endophyte-mediated accumulation of metals by tall fescue  

SciTech Connect

Laser-induced breakdown spectroscopy (LIBS) was used to determine the impact of endophyte (Neotyphodium sp.) infection on elemental composition of tall fescue (Festuca arundinacea). Leaf material from endophyte-infected (E+) and endophyte-free (E-) tall fescue populations in established plots was examined. Leaf-tissue digestates were also tested for metals, by inductively coupled plasma (ICP) mass spectrometry (MS). Seven of eleven metals (Ca, Mg, Fe, Mn, Cu, Ni, and Zn) were measured by both techniques at concentrations great enough for a reliable comparison. Mg, Zn, and Cd, a toxic metal that can be present in forage, were readily detected by LIBS, even though Cd concentrations in the plants were below levels typically achieved using ICP MS detection. Implications of these results for research on forage analysis and phytoremediation are discussed.

Martin, Madhavi Z.; Stewart, Arthur J.; Gwinn, Kimberley D.; Waller, John C.

2010-05-01

221

A virtual tall tower network for understanding continental sources and sinks of CO2  

SciTech Connect

Our understanding of the North American terrestrial carbon cycle is limited by both a lack of continental atmospheric CO2 data, and by a need for methods to interpret these and other continental data with confidence. In response to this challenge a rapid expansion of the N. American carbon cycle observational network is underway. This expansion includes a network of continuous, continental CO2 mixing ratio observations being collected at a subset of AmeriFlux towers. Progress in developing this resource includes instrument development, site installation, calibration and intercalibration efforts, and initiation of a uniform data product. Progess in applying these data include proposed methods for interpreting surface layer measurements in atmospheric inversions (the virtual tall towers approach), examination of coherence patterns in continental mixing ratios in response to weather and climate, and application of these mixing ratio measurements in formal atmospheric inversions. Future work will merge these methods with interpretation of flux towers observations of terrestrial carbon fluxes in an effort to create a single coherent diagnosis of North American terrestrial carbon fluxes over a multi-year period.

Davis, K.J.; Richardson, S.J.; Miles, N.L.

2007-03-09

222

Impacts of experimental trampling on tall alpine herbfields and subalpine grasslands in the Australian Alps.  

PubMed

The Australian Alps, which are of high conservation value, are popular summer bushwalking destinations. Experimental trampling trials using a standardized methodology were conducted to determine the resistance and resilience of the two common vegetation types: tall alpine herbfield and subalpine grasslands. Vegetation parameters were measured in lanes subject to control (no trampling), 30, 100, 200, 500 and 700 passes at five sites prior to trampling, immediately post trampling, 2 weeks, 6 weeks and 1 year post trampling. Vegetation height, cover of graminoids and herbs, as well as net species richness all declined with trampling, while litter cover increased. Thresholds for damage varied between the two communities and among the different vegetation parameters. The resistance indices for the two communities (number of passes resulting in 50% reduction in vegetation cover), however, were similar at around 440-450 passes indicating that these two communities are among the most resistant of the 19 alpine-subalpine communities that have been tested around the world, but only of moderate resistance compared to non-alpine communities. The two communities showed limited recovery with damage still evident 1 year post trampling. This indicates that they have only moderate tolerance to damage due to moderate resistance, but low resilience. PMID:19854561

Pickering, Catherine Marina; Growcock, Andrew J

2009-01-01

223

Tall Tower and Aircraft Measurements of Carbon Dioxide: Prospects for the North American Carbon Program (NACP)  

NASA Astrophysics Data System (ADS)

For over 10 years we have monitored carbon dioxide mixing ratios over North America from tall (up to 600 m) transmitter towers and aircraft (up to 8 km). The data, though sparse, give a measure of the temporal and 3D spatial variability of CO2 over the continent. Analysis of these data suggest ways in which measurements from a more extensive network of sites, such as is envisioned for the NACP, could be used to estimate net CO2 surface fluxes on a regional scale (i.e., roughly one million square kilometers). We also evaluate the use of mixing ratio data from short (30-100 m) towers for regional flux estimates. Short towers are widely used for local scale (a few hectares) measurements of atmosphere/surface exchange of CO2 (FLUXNET). The results indicate that measurements of CO2 mixing ratios at continental tower sites can be used to constrain estimates of regional CO2 fluxes. However, at present CO2 mixing ratios are measured with sufficient accuracy relative to global reference gas standards at only a few continental sites.

Bakwin, P.

2003-04-01

224

Fabrication process for tall, sharp, hollow, high aspect ratio polymer microneedles on a platform  

NASA Astrophysics Data System (ADS)

This paper reports on a new lithographic process for fabricating arrays of tall, high aspect ratio (defined as height/wall thickness), hollow, polymer microneedles on a platform. The microneedles feature a high sharpness (down to 3 µm tip radius) and aspect ratio (>65) which is a factor 2 and 4 better than the state of the art, respectively. The maximum achievable needle shaft length is over 1 mm. The improved performance was obtained by using an anisotropically patterned silicon substrate covered with an antireflective layer as mold for the needle tip and an optimized SU-8 lithographic process. Furthermore, a platform containing liquid feedthroughs holding an arbitrary number of needles out of plane can be manufactured with only one additional process step. The high aspect ratio microneedles undergo failure at the critical load of around 230 mN in the case of 1 mm long hollow needles with triangular cross section and a base of 175 µm. Penetration into human skin is demonstrated as well.

Ceyssens, Frederik; Chaudhri, Buddhadev Paul; Van Hoof, Chris; Puers, Robert

2013-07-01

225

Numerical Modelling of the Sound Field Near a Tall Building with Balconies Near a Road  

NASA Astrophysics Data System (ADS)

A two-dimensional, boundary element numerical model is used to study the sound field in the region of balconies in a tall building close to a roadway. The sound pressure level relative to the free field level is calculated within the balconies on the first four floors, and at positions 1 m outside the external facade. The effects of shielding of the source by the balcony wall are found to be largely cancelled by the strong reflected sound from the ceiling and rear wall of the balcony. The insertion loss resulting from eight different applications of an efficient sound absorbing material to the building surfaces is calculated. It is found that treatment of the ceiling or the rear wall of the balcony is the most efficient in terms of noise reduction, producing values of between about 5 and 8 dB for a broad band spectrum characteristic of A-weighted road traffic noise. The maximum effects obtained for a combination of surface treatments is 10 dB. Spectra of the sound pressure level relative to the free field level are compared for a receiver position in one balcony and it is observed that the main effect of an absorbent is to reduce the high frequency resonance peaks.

Hothersall, D. C.; Horoshenkov, K. V.; Mercy, S. E.

1996-12-01

226

Gender effects of tall oil versus soybean phytosterols as cholesterol-lowering agents in hamsters.  

PubMed

To examine the effect of gender on the mechanisms of action of phytosterols extracted from tall oil (TO) and soybean (SB) on cholesterol and phytosterol metabolism, male and female hamsters were fed cholesterol-enriched diets containing 0.5 or 1% (w/w) TO or SB phytosterols for 90 days. Plasma lipoprotein cholesterol profile and tissue phytosterol and cholesterol biosynthesis levels were determined. Mean plasma total-cholesterol level in females fed 1% (w/w) SB was reduced (p<0.05) by 44%, while in males it was lowered (p<0.05) by 25% compared with their respective controls. Moreover, mean plasma total-cholesterol level was reduced (p<0.05) in male hamsters by -31% and female hamsters by -32% when fed 1% (w/w) TO. Cholesterol biosynthesis was higher (p<0.05) by twofold in groups fed TO at 0.5 and 1% (w/w) concentrations, compared with SB. Hamsters fed TO at 0.5 and 1% (w/w) levels also had higher (p<0.05) hepatic and enterocytic campesterol contents than SB-fed animals. These findings demonstrate gender differences in cholesterol metabolism in TO- and SB-fed hamsters. The results suggest that TO, conversely to SB phytosterol, is a more effective cholesterol-lowering agent in male, but not as much in female, hamsters, over a feeding period of 90 days. PMID:10030459

Ntanios, F Y; MacDougall, D E; Jones, P J

1998-01-01

227

Factors associated with plant species richness in a coastal tall-grass prairie  

USGS Publications Warehouse

In this study we examine the factors associated with variations in species richness within a remnant tall-grass prairie in order to gain insight into the relative importance of controlling variables. The study area was a small, isolated prairie surrounded by wetlands and located within the coastal prairie region, which occurs along the northwestern Gulf of Mexico coastal plain. Samples were taken along three transects that spanned the prairie. Parameters measured included micro-elevation, soil characteristics, indications of recent disturbance, above-ground biomass (including litter), light penetration through the plant canopy, and species richness. Species richness was found to correlate with micro-elevation, certain soil parameters, and light penetration through the canopy, but not with above-ground biomass. Structural equation analysis was used to assess the direct and indirect effects of micro-elevation, soil properties, disturbance, and indicators of plant abundance on species richness. The results of this analysis showed that observed variations in species richness were primarily associated with variations in environmental effects (from soil and microtopography) and were largely unrelated to variations in measures of plant abundance (biomass and light penetration). These findings suggest that observed variations in species richness in this system primarily resulted from environmental effects on the species pool. These results fit with a growing body of information that suggests that environmental effects on species richness are of widespread importance.

Grace, J. B.; Allain, L.; Allen, C.

2000-01-01

228

Photographer: KSC Space Shuttle Orbiter Enterprise, mated to a 15-story-tall external propellant  

NASA Technical Reports Server (NTRS)

Photographer: KSC Space Shuttle Orbiter Enterprise, mated to a 15-story-tall external propellant tank and twin inert solid rocket boosters on top of a Mobile Launcher Platform, is rolled back to the Vehicle Assembly Building from Lauch Complex 39's Pad A July 23 at the completion of nearly three months of fit and function checks at the shuttle launch site as part of the exercise designed to help clear the way for the liftoff of its sister ship Columbia. The massive Crawler Transporter began moving its 11 million pound load the 3.5 miles from pad A to the VAB at 10:23 a.m. and reached the doorway to High Bay 1 at 3:48p.m. following serveral days of fit checks of modified extermiable platforms in the assembly bay, the nonlaunchable shuttle will be destacked. Enterprise will be returned to Rockwell International and stripped of parts for integration into orbiter destined for space, while the external tank and solid booster will be returned to their respective prime contractors and refurbished for use on a later shuttle mission.

1980-01-01

229

Effect of the surface thermal radiation on turbulent natural convection in tall cavities of façade elements  

NASA Astrophysics Data System (ADS)

The effect of the surface thermal radiation in tall cavities with turbulent natural convection regime was analyzed and quantified numerically. The parameters considered were: the Rayleigh number 109 1012, the aspect ratio 20, 40 and 80 and the emmisivity 0.0 1.0. The percentage contribution of the radiative surface to the total heat transfer has a maximum value of 15.19% ( Ra = 109, A = 20) with emissivity equal to 1.0 and a minimum of 0.5% ( Ra = 1012, A = 80) with ?* = 0.2. The average radiative Nusselt number for a fixed emissivity is independent of the Rayleigh number, but for a fixed Rayleigh number diminishes with the increase of the aspect ratio. The results indicate that the surface thermal radiation does not modify significantly the flow pattern in the cavity, just negligible effects in the bottom and top of the cavity were observed. Two different temperature patterns were observed a conductive regime Ra = 109 and a boundary layer regime Ra = 1012.

Xamán, J. P.; Hinojosa, J. F.; Flores, J. J.; Cabanillas, R. E.

2008-12-01

230

Biosolids applications to tall fescue have long-term influence on soil nitrogen, carbon, and phosphorus.  

PubMed

Repeated applications of biosolids provide long-term benefits by increasing soil organic matter and N supply but can cause excess accumulation of P. Our objective was to determine the residual effects of repeated surface applications of biosolids on N availability and fate, tall fescue ( Schreb.) response, soil C, and P. A field experiment was started in 1993 to compare two biosolids products, each applied at three rates (6.7, 13.4, and 20.1 Mg ha yr), with synthetic N fertilizer (0 and 403 kg N ha yr as ammonium nitrate). Treatments were surface applied for 10 yr, followed by a 9-yr residual period where all plots received a reduced rate of inorganic N (202 kg N ha yr). Annual measurements included forage yield, N uptake, and soil nitrate N. Soil samples collected in 2002 and 2011 were analyzed for total C and N and Bray-1 P. Cumulative apparent N recoveries in harvested grass (1993-2010) were 51% for biosolids N and 72% for ammonium nitrate. Net fall soil nitrate N summed for the period 1993-2002 ranged from <1 to 3% of N applied. The N applied that was accounted for in forage and soil averaged 74% for biosolids and 73% for ammonium nitrate. Soil C increased in the biosolids treatments, and the increase was equivalent to 27% of biosolids C. Bray-1 P remained at excessive levels (338-629 mg P kg soil) 9 yr after the last biosolids application. PMID:23673844

Cogger, Craig G; Bary, Andy I; Myhre, Elizabeth A; Fortuna, Ann-Marie

2013-01-01

231

[Limited but potential efficacy by graft-versus-leukemia (GVL) for Pro T-ALL].  

PubMed

We present a 22-year-old male diagnosed with pro T-acute lymphoblastic leukemia (ALL). His laboratory test showed 181,900/microL of WBC complicated with lymphoadenopathy, pleural effusion, pericardial effusion and hepatosplenomegaly at the onset. Flow cytometry analysis of the leukemic cells showed cCD3+, CD7+, CD2+, CD1a-, CD3-, CD5-, CD4-, CD8-, CD34+, and HLA-DR+ as a pro T-cell phenotype. The patient was treated with induction therapy followed by 3 courses of consolidation therapy and achieved his first complete remission. He underwent up-front stem cell transplantation (SCT) from an HLA-full matched sibling, with early relapse just before transplantation. The conditioning regimen consisted of fludarabine (100 mg/m2) and melphalan (180 mg/m2). He relapsed with an extramedullary mass (gingival, testis, and femoral muscles) 1 year after transplantation. Since bone marrow involvement was not apparent, he received involved field radiation therapy (25.2 Gy/14 frequencies) in each mass. Six months after extramedullary relapse, bone marrow relapse occurred, and the patient died of sepsis due to Pseudomonas aeruginosa during re-induction therapies. Based on the immature T cell phenotype frequently with myeloid markers, a graft-versus- leukemic effect might be expected after allogeneic SCT for Pro T-ALL and a positive indication of SCT for this disease should be considered. PMID:19011341

Imataki, Osamu; Koike, Airi; Iwabu, Masako; Shintani, Takamichi; Waki, Fusako; Ohue, Yukiko; Ohnishi, Hiroaki; Ishida, Toshihiko

2008-11-01

232

Corking nano test tubes by chemical self-assembly.  

PubMed

There is tremendous current interest in using nanoparticles to deliver biomolecules and macromolecules (e.g., drugs and DNA) to specific sites in living systems. Release of the biomedical payload from the nanoparticle can be accomplished by chemical or enzymatic degradation of the nanoparticle or of the link between the payload and the nanoparticle. We are exploring an alternative payload-release strategy that builds on our work on template-synthesized nano test tubes. These are hollow nanotubes that are closed on one end and open on the other, and the dimensions can be controlled at will. If these nano test tubes could be filled with a payload and then the open end corked with a chemically labile cap, they might function as a universal delivery vehicle. We show here that silica nano test tubes can be covalently corked by chemical self-assembly of nanoparticles to the tubes. We also show that the nanoparticle corks remain attached to the mouths of the nano test tubes after liberation from the alumina template. For this proof-of-principle study, we used simple imine linkages to attach the corks to the test tubes. Schiff's bases are thermodynamically unstable in the presence of water; however, the multiple points of contact between the nano test tubes and nanoparticles allow the assembled structure to be metastable under our experimental conditions. Other chemical linkages-either more or less stable-may be more appropriate for other applications, and these are currently under development. PMID:16568992

Hillebrenner, Heather; Buyukserin, Fatih; Kang, Myungchan; Mota, Miguel O; Stewart, Jon D; Martin, Charles R

2006-04-01

233

Micron sized nano-materials  

Microsoft Academic Search

The difference in “diameter” from micron to nano is 103 which is 109 (a billion) times difference in volume or mass. This implies that the properties that we have intuitive feeling for at the micron scale are considerably modified at masses a billion times smaller. Indeed it is for this reason that “nano” materials have been exploited. For example, in

Alan F. Rawle

2007-01-01

234

Antitumor activity of a human cytotoxic T-cell line (TALL104) in brain tumor xenografts 1  

Microsoft Academic Search

Malignant glioma in adults and primitive neuroectoder- mal tumors\\/medulloblastomas in children are the most common malignant primary brain tumors that either respond poorly to current treatment or tend to recur. Adoptive therapy with TALL-104 cells—an IL-2-depen- dent, major histocompatibility complex nonrestricted, cytotoxic T-cell line—has demonstrated signiécant antitu- mor activity against a broad range of implanted or spon- taneously arising tumors.

Birgit Geoerger; Cheng-Bi Tang; Alessandra Cesano; Sophie Visonneau; Sunil Marwaha; Kevin D. Judy; Leslie N. Sutton; Daniela Santoli; Peter C. Phillips

235

Upregulation of T-Cell-Specific Transcription Factor Expression in Pediatric T-Cell Acute Lymphoblastic Leukemia (T-ALL)  

PubMed Central

Objective: T-cell acute lymphoblastic leukemia (T-ALL) is associated with recurrent chromosomal aberrations andabnormal ectopic gene expression during T-cell development. In order to gain insight into the pathogenesis of T-ALLthis study aimed to measure the level of expression of 7 T-cell oncogenes (LMO2, LYL1, TAL1, TLX1, TLX3, BMI1, andCALM-AF10) in pediatric T-ALL patients Material and Methods: LMO2, LYL1, TLX1, TLX3, BMI1, TAL1, and CALM-AF10 expression was measured usingquantitative real-time PCR in 43 pediatric T-ALL patients. Results: A high level of expression of LMO2, LYL1, TAL1, and BMI1 genes was observed in a large group of T-ALL.Several gene expression signatures indicative of leukemic arrest at specific stages of normal thymocyte development(LYL1 and LMO2) were highly expressed during the cortical and mature stages of T-cell development. Furthermore,upregulated TAL1 and BMI1 expression was observed in all phenotypic subgroups. In all, 6 of the patients had TLX1and TLX3 proto-oncogene expression, which does not occur in normal cells, and none of the patients had CALM-AF10fusion gene transcription. Expression of LYL1 alone and LMO2-LYL1 co-expression were associated with mediastinalinvolvement; however, high-level oncogene expression was not predictive of outcome in the present pediatric T-ALLpatient group, but there was a trend towards a poor prognostic impact of TAL1 and/or LMO2 and/or LYL1 protooncogeneexpression. Conclusion: Poor prognostic impact of TAL1 and/or LMO2 and/or LYL1 proto-oncogene expression indicate the needfor extensive study on oncogenic rearrangement and immunophenotypic markers in T-ALL, and their relationship totreatment outcome. Conflict of interest:None declared.

Sayitoglu, Muge; Erbilgin, Yucel; Hat?rnaz Ng, Ozden; Y?ld?z, Inci; Celkan, Tiraje; Anak, Sema; Devecioglu, Omer; Aydogan, Gonul; Karaman, Serap; Sarper, Nazan; Timur, Cetin; Ure, Umit; Ozbek, Ugur

2012-01-01

236

Responses of MxPPO overexpressing transgenic tall fescue plants to two diphenyl-ether herbicides, oxyfluorfen and acifluorfen  

Microsoft Academic Search

We generated transgenic tall fescue (Festuca arundinacea Schreb. cv. Kentucky-31) plants harboring a synthetic Myxococcus xanthus protoporphyrinogen oxidase (MxPPO) gene through Agrobacterium-mediated gene transfer. Successful integration of the transgene into the genome of transgenic plants confirmed by polymerase\\u000a chain reaction (PCR) and Southern blot analysis, and the functional expression of the MxPPO gene at the mRNA level in transgenic lines

Ki-Won Lee; Nagib Ahsan; Sang-Hoon Lee; Dong-Gi Lee; Kyung-Hee Kim; Iftekhar Alam; Suk-Yoon Kwon; Jin-Seog Kim; Kyoungwhan Back; Sung Sil Lee; Byung-Hyun Lee

2008-01-01

237

Water-use patterns of tall fescue and hybrid bluegrass cultivars subjected to ET-based irrigation scheduling  

Microsoft Academic Search

In turf industry, the ability of a cultivar to use less water is an important consideration, especially where rainfall and\\u000a irrigation water are insufficient. Knowledge of turf grass water-use patterns is therefore important for developing efficient\\u000a water management practices and also for selection of drought-resistant cultivars. We evaluated the soil water?use patterns\\u000a of tall fescue and hybrid bluegrasses cultivars irrigated

Leonard J. M. Githinji; Jacob H. Dane; Robert H. Walker

2009-01-01

238

Investigation of a long time series of CO2 from a tall tower using WRF-SPA  

NASA Astrophysics Data System (ADS)

Atmospheric observations from tall towers are an important source of information about CO2 exchange at the regional scale. Here, we have used a forward running model, WRF-SPA, to generate a time series of CO2 at a tall tower for comparison with observations from Scotland over multiple years (2006-2008). We use this comparison to infer strength and distribution of sources and sinks of carbon and ecosystem process information at the seasonal scale. The specific aim of this research is to combine a high resolution (6 km) forward running meteorological model (WRF) with a modified version of a mechanistic ecosystem model (SPA). SPA provides surface fluxes calculated from coupled energy, hydrological and carbon cycles. This closely coupled representation of the biosphere provides realistic surface exchanges to drive mixing within the planetary boundary layer. The combined model is used to investigate the sources and sinks of CO2 and to explore which land surfaces contribute to a time series of hourly observations of atmospheric CO2 at a tall tower, Angus, Scotland. In addition to comparing the modelled CO2 time series to observations, modelled ecosystem specific (i.e. forest, cropland, grassland) CO2 tracers (e.g., assimilation and respiration) have been compared to the modelled land surface assimilation to investigate how representative tall tower observations are of land surface processes. WRF-SPA modelled CO2 time series compares well to observations (R2 = 0.67, rmse = 3.4 ppm, bias = 0.58 ppm). Through comparison of model-observation residuals, we have found evidence that non-cropped components of agricultural land (e.g., hedgerows and forest patches) likely contribute a significant and observable impact on regional carbon balance.

Smallman, Luke; Williams, Mathew; Moncrieff, John B.

2013-04-01

239

On the formation of degradation products from the pyrolysis of tall oil fatty acids with kraft lignin  

Microsoft Academic Search

Mixtures of tall oil fatty acids and kraft lignin from southern pine wood were pyrolyzed at 160 C and 280 C with or without\\u000a exclusion of oxygen. In addition to fatty acids of various chain lengths and aromatic degradation products from lignin, a\\u000a number of homologousn-alkylbenzenes were formed (ca. 1.5%) and characterized by gas chromatography-mass spectrometry. The possible ways of

H. Traitler; K. Kratzl

1980-01-01

240

Comparative photosynthesis, growth, productivity, and nutrient use efficiency among tall- and short-stemmed rain-fed cassava cultivars  

Microsoft Academic Search

Field trials under rain-fed conditions at the International Center for Tropical Agriculture (CIAT) in Colombia were conducted\\u000a to study the comparative leaf photosynthesis, growth, yield, and nutrient use efficiency in two groups of cassava cultivars\\u000a representing tall (large leaf canopy and shoot biomass) and short (small leaf canopy and shoot biomass) plant types. Using\\u000a the standard plant density (10,000 plants

M. A. El-Sharkawy; S. M. De Tafur

2010-01-01

241

Exploring Materials: Nano Gold  

NSDL National Science Digital Library

In this activity, learners discover that nanoparticles of gold can appear red, orange or even blue. They learn that a material can act differently when itâs nanometer-sized. Use this activity to explain how stained glass gets its different colors. Note: the cost for the materials in this activity is quite high. However, this is a one-time cost, since the nano gold is kept in vials at all time and thus should not be used up. SAFETY: Do not let visitors ingest the contents of the vials. Keep vials sealed shut. Use caution when handling the stained glass samples. Do not remove them from their protective case.

Network, Nanoscale I.; Sciencenter

2011-01-01

242

Ascorbic Acid Enhances the Accumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in Roots of Tall Fescue (Festuca arundinacea Schreb.)  

PubMed Central

Plant contamination by polycyclic aromatic hydrocarbons (PAHs) is crucial to food safety and human health. Enzyme inhibitors are commonly utilized in agriculture to control plant metabolism of organic components. This study revealed that the enzyme inhibitor ascorbic acid (AA) significantly reduced the activities of peroxidase (POD) and polyphenol oxidase (PPO), thus enhancing the potential risks of PAH contamination in tall fescue (Festuca arundinacea Schreb.). POD and PPO enzymes in vitro effectively decomposed naphthalene (NAP), phenanthrene (PHE) and anthracene (ANT). The presence of AA reduced POD and PPO activities in plants, and thus was likely responsible for enhanced PAH accumulation in tall fescue. This conclusion is supported by the significantly enhanced uptake of PHE in plants in the presence of AA, and the positive correlation between enzyme inhibition efficiencies and the rates of metabolism of PHE in tall fescue roots. This study provides a new perspective, that the common application of enzyme inhibitors in agricultural production could increase the accumulation of organic contaminants in plants, hence enhancing risks to food safety and quality.

Gao, Yanzheng; Li, Hui; Gong, Shuaishuai

2012-01-01

243

Effects of multiple climate change factors on the tall fescue-fungal endophyte symbiosis: infection frequency and tissue chemistry.  

PubMed

• Climate change (altered CO(2) , warming, and precipitation) may affect plant-microbial interactions, such as the Lolium arundinaceum-Neotyphodium coenophialum symbiosis, to alter future ecosystem structure and function. • To assess this possibility, tall fescue tillers were collected from an existing climate manipulation experiment in a constructed old-field community in Tennessee (USA). Endophyte infection frequency (EIF) was determined, and infected (E+) and uninfected (E-) tillers were analysed for tissue chemistry. • The EIF of tall fescue was higher under elevated CO(2) (91% infected) than with ambient CO(2) (81%) but was not affected by warming or precipitation treatments. Within E+ tillers, elevated CO(2) decreased alkaloid concentrations of both ergovaline and loline, by c. 30%; whereas warming increased loline concentrations 28% but had no effect on ergovaline. Independent of endophyte infection, elevated CO(2) reduced concentrations of nitrogen, cellulose, hemicellulose, and lignin. • These results suggest that elevated CO(2) , more than changes in temperature or precipitation, may promote this grass-fungal symbiosis, leading to higher EIF in tall fescue in old-field communities. However, as all three climate factors are likely to change in the future, predicting the symbiotic response and resulting ecological consequences may be difficult and dependent on the specific atmospheric and climatic conditions encountered. PMID:21070246

Brosi, Glade B; McCulley, Rebecca L; Bush, Lowell P; Nelson, Jim A; Classen, Aimée T; Norby, Richard J

2011-02-01

244

EDITORIAL: Nano Meets Spectroscopy Nano Meets Spectroscopy  

NASA Astrophysics Data System (ADS)

The multidisciplinary two-day Nano Meets Spectroscopy (NMS) event was held at the National Physical Laboratory (NPL), Teddington, UK, in September 2011. The event was planned from the outset to be at the interface of several areas—in particular, spectroscopy and nanoscience, and to bring together topics and people with different approaches to achieving common goals in biomolecular science. Hence the meeting cut across traditional boundaries and brought together researchers using diverse techniques, particularly fluorescence and Raman spectroscopy. Despite engaging common problems, these techniques are frequently seen as mutually exclusive with the two communities rarely interacting at conferences. The meeting was widely seen to have lived up to its billing in good measure. It attracted the maximum capacity of ~120 participants, including 22 distinguished speakers (9 from outside the UK), over 50 posters and a vibrant corporate exhibition comprising 10 leading instrument companies and IOP Publishing. The organizers were Professor David Birch (Chair), Dr Karen Faulds and Professor Duncan Graham of the University of Strathclyde, Professor Cait MacPhee of the University of Edinburgh and Dr Alex Knight of NPL. The event was sponsored by the European Science Foundation, the Institute of Physics, the Royal Society of Chemistry, NPL and the Scottish Universities Physics Alliance. The full programme and abstracts are available at http://sensor.phys.strath.ac.uk/nms/program.php. The programme was quite ambitious in terms of the breadth and depth of scope. The interdisciplinary and synergistic concept of 'X meets Y' played well, cross-fertilization between different fields often being a source of inspiration and progress. Fluorescence and Raman spectroscopy provided the core, but the meeting had little repetition and also attracted contributions on more specialist techniques such as CARS, super-resolution, single molecule and chiral methods. In terms of application the event bridged as far as medical application of nanotechnologies. It could have turned out that such a hotchpotch produced an incoherent event that lacked direction and focus, but in truth, as the feedback showed, the delegates revelled in the diversity and depth of quality. Excellent speakers, the common application to biomolecules and common language of spectroscopy were probably the reasons why things worked out so well. I am delighted to bring together in this special feature in Measurement Science and Technology a selection of contributions from the meeting and I thank all the authors for their excellent contributions. Included are papers on nanoparticles, plasmonics, sensing and imaging. This special feature, and indeed similar meetings in the future, will undoubtedly help sustain the 'nanomeeters' message of NMS.

Birch, David J. S.

2012-08-01

245

Continuous CO2/CH4 measurement at Zotino Tall Tower Observatory (ZOTTO) in Central Siberia  

NASA Astrophysics Data System (ADS)

Global climate change has particular impact on Siberia, where one tenth of global vegetation and soil carbon is stored. The increase in temperature lengthens the vegetation period and consequently enlarges the carbon sink. On the other hand, a warming climate will enhance thawing of permafrost which contains organic carbon that can be released either as carbon dioxide or methane depending on the local hydrological conditions. Long-term biogeochemical trace gas measurements on tall towers (> 250 m) over continents help to improve the knowledge about surface source/sink processes at regional to continental scales. Without the usage of aircrafts, the height of the tower allows regular probing of the mixed part of the boundary layer, which is - unlike the surface layer - only moderately influenced by diurnal variations of local surface fluxes and thus representative for a larger region (~1000km). The recently established Zotino Tall Tower Observatory (ZOTTO, 304 m, www.zottoproject.org) is located near the village of Zotino at the Yenisei River in central Siberia (60° N, 89° E). The ZOTTO facility was built in the perspective to monitor and determine variability and trends in the carbon balance of central Siberian forests. Since April 2009 we measure CO2 and CH4 from 6 height levels reaching from 4 to 301 m with an analyzer based on the cavity ring-down spectroscopy technique (Picarro Inc., CA, USA, model G1301). Experiments have shown that reliable accurate measurements can be obtained even without drying the sample gas. To obtain dry air mixing ratios for CO2 and CH4, the simultaneous water vapor measurements are used to correct dilution and pressure broadening effects, resulting in a precision and accuracy that is better than WMO recommendations. Furthermore, the system requires only a very low amount of calibration gases, because calibration takes place only every 100 hrs. These two aspects allow keeping maintenance low, which is an important requirement for this remote station. In each sampling line buffer volumes integrate the atmospheric signal over a typical time period of 40 minutes. With these the periodic switching from line to line every three minutes with only one single analyzer provides a quasi continuous, concurrent measurement from each height level. As a consequence of the averaging as well as the precision of the analyzer, the data show a low noise level and still moderately high temporal resolution, and gradients between different levels can be determined to a very high accuracy. The new data from 2009 and 2010 will be presented and interpreted in the context of regional sources and sinks of CO2 and CH4 in central Siberia. As the nocturnal boundary develops during night, it locally traps respired CO2 and CH4 and builds up vertical gradients. The analysis of the gradients allows estimating the trapped carbon amount in this layer which can be assigned to a certain region by using the Lagrangian transport model STILT.

Winderlich, Jan; Chen, Huilin; Höfer, Annette; Gerbig, Christoph; Panov, Alexey; Heimann, Martin

2010-05-01

246

Measuring plant diversity in the tall threetip sagebrush steppe: influence of previous grazing management practices.  

PubMed

In July 2000, a 490-ha wildfire burned a portion of a long-term grazing study that had been established in 1924 at the US Sheep Experiment Station north of Dubois, Idaho, USA. Earlier vegetation measurements in this tall threetip sagebrush (Artemisia tripartita spp. tripartita) bunchgrass plant community documented significant changes in vegetation due to grazing and the timing of grazing by sheep. A study was initiated in May 2001 using 12 multiscale modified Whittaker plots to determine the consequences of previous grazing practices on postfire vegetation composition. Because there was only one wildfire and it did not burn all of the original plots, the treatments are not replicated in time or space. We reduce the potential effects of psuedoreplication by confining our discussion to the sample area only. There were a total of 84 species in the sampled areas with 69 in the spring-grazed area and 70 each in the fall- and ungrazed areas. Vegetation within plots was equally rich and even with similar numbers of abundant species. The spring-grazed plots, however, had half as much plant cover as the fall- and ungrazed plots and the spring-grazed plots had the largest proportion of plant cover composed of introduced (27%) and annual (34%) plants. The fall-grazed plots had the highest proportion of native perennial grasses (43%) and the lowest proportion of native annual forbs (1%). The ungrazed plots had the lowest proportion of introduced plants (4%) and the highest proportion of native perennial forbs (66%). The vegetation of spring-grazed plots is in a degraded condition for the environment and further degradation may continue, with or without continued grazing or some other disturbance. If ecosystem condition was based solely on plant diversity and only a count of species numbers was used to determine plant diversity, this research would have falsely concluded that grazing and timing of grazing did not impact the condition of the ecosystem. PMID:14753648

Seefeldt, Steven S; McCoy, Scott D

2003-08-01

247

Energy and protected protein supplements to lambs on endophyte-infected tall fescue pasture.  

PubMed

The effect of supplements on intake, digestibility, N retention, ADG and blood and body composition of growing lambs fed cut herbage or grazing KY 31 tall fescue (Festuca arundinacea Schreb.) pastures at two levels of N fertilization (92 and 318 kg/ha) was determined. Supplements were corn (C), corn with soybean meal (U-SBM) and corn with heat-treated SBM (H-SBM). Metabolism trials were run at three growth stages in the 1st yr with 24 lambs. Although all supplements increased total DMI and DM digestibility, they decreased NDF digestibility relative to grass (G), with no difference between supplements; C depressed apparent CP digestibility. Nitrogen retention increased from -2.5 g/d on G to -.4 g/d on C and 3.2 and 4.1 g/d on U-SBM and H-SBM, respectively, for combined periods and N rates. Blood urea N (BUN) concentrations differed (P less than .01) in the following order: G greater than U-SBM greater than H-SBM greater than C. In the 2nd yr, lambs (n = 64) grazed fescue pastures at the same N fertilizer rates and were given the same supplements. Gains were not different (P less than .05) on low-N (LN) and high-N (HN) pastures. Seasonal ADG were 80, 115, 122 and 130 g/d for G, C, U-SBM and H-SBM treatments, respectively, with no difference (P less than .05) between U-SBM and H-SBM. At slaughter, lambs from G had lower dressing percentages (P less than .05) and fat content (P less than .01) than lambs on C, U-SBM and H-SBM treatments, with no differences between supplements. Results indicated a better performance of growing lambs on fescue with both energy and protein supplements. Response to protected vs unprotected protein was small. PMID:2005030

Daura, M T; Reid, R L

1991-01-01

248

Immunophenotypic analysis of T-acute lymphoblastic leukemia. A CD5-based ETP-ALL perspective of non-ETP T-ALL.  

PubMed

T-cell antigens [CD5,CD1a,CD8] define early T-cell precursor acute lymphoblastic leukemia (ETP-ALL). To understand immature T-ALL of which ETP-ALL is part, we used these antigens to subcategorize non-ETP T-ALL for examining expression of myeloid/stem cell antigens (M/S) and clinical features. Using CD5 (+/-) to start categorization, we studied 69 routinely immunophenotyped patients with T-ALL. CD5(-) was a homogenous (CD8,CD1a)(-) M/S(+) ETP-ALL group (n = 9). CD5(+) cases were (CD8,CD1a)(-) pre-T-ALL (n = 22) or (CD8,CD1a)(+) (n = 38) thymic/cortical T-ALL; M/S(+) 20/22 (90.91%) in former and 22/38 (57.89%) in latter (P = 0.007). ETP- and pre-T-ALL together (CD1a(-) ,CD5(-/+) immature T-ALL group) were nearly always M/S(+) (29/31; 93.55%). In multivariate analysis, only ETP-ALL predicted poor overall survival (P = 0.02). We conclude (i) CD5 negativity in T-ALL almost always means ETP-ALL. CD1a and CD8 negativity, as much as CD5, marks immaturity in T-ALL, and the CD5(+/-) /CD1a(-) /CD8(-) immature T-ALL group needs further study to understand the biology of the T-ALL-myeloid interface. (ii) ETP-ALL patients may be pre-T-ALL if CD2(+) ; CD2(+) , conversely, CD5(-) /CD1a(-) /CD8(-) pre-T ALL patients are ETP-ALL. (iii) Immunophenotypic workup of T-ALL must not omit CD1a, CD5, CD8 and CD2, and positivity of antigens should preferably be defined as recommended for ETP-ALL, so that this entity can be better evaluated in future studies of immature T-ALL, a group to which ETP-ALL belongs. (iv) ETP-ALL has poor prognosis. PMID:24329989

Chopra, Anita; Bakhshi, Sameer; Pramanik, Suman Kumar; Pandey, Ravindra Mohan; Singh, Saroj; Gajendra, Smeeta; Gogia, Ajay; Chandramohan, Jagan; Sharma, Atul; Kumar, Lalit; Seth, Rachna; Rai, Sandeep; Kumar, Rajive

2014-03-01

249

Silicon-carbon nano-structures to nano-tubes  

Microsoft Academic Search

There have been continuing efforts to stabilize silicon cage-type nano-structures or nano-tubes which can be used in similar ways as the carbon-based fullerene structures. This is due to the fact that the current semiconductor industries are based on silicon. Silicon carbide is the focus of scientific research due to its potential use even in extreme conditions, such as extreme high-temperature,

M. N. Huda; Leonard Kleinman; A. K. Ray

2006-01-01

250

Nano surface generation of grinding process using carbon nano tubes  

Microsoft Academic Search

Nano surface finish has become an important parameter in the semiconductor, optical, electrical and mechanical industries.\\u000a The materials used in these industries are classified as difficult to machine materials such as ceramics, glasses and silicon\\u000a wafers. Machining of these materials up to nano accuracy is a great challenge in the manufacturing industry. Finishing of\\u000a micro components such as micro-moulds, micro-lenses

S. Prabhu; B. K. Vinayagam

2010-01-01

251

Nano-optomechanical transducer  

DOEpatents

A nano-optomechanical transducer provides ultrabroadband coherent optomechanical transduction based on Mach-wave emission that uses enhanced photon-phonon coupling efficiencies by low impedance effective phononic medium, both electrostriction and radiation pressure to boost and tailor optomechanical forces, and highly dispersive electromagnetic modes that amplify both electrostriction and radiation pressure. The optomechanical transducer provides a large operating bandwidth and high efficiency while simultaneously having a small size and minimal power consumption, enabling a host of transformative phonon and signal processing capabilities. These capabilities include optomechanical transduction via pulsed phonon emission and up-conversion, broadband stimulated phonon emission and amplification, picosecond pulsed phonon lasers, broadband phononic modulators, and ultrahigh bandwidth true time delay and signal processing technologies.

Rakich, Peter T; El-Kady, Ihab F; Olsson, Roy H; Su, Mehmet Fatih; Reinke, Charles; Camacho, Ryan; Wang, Zheng; Davids, Paul

2013-12-03

252

NanoKids(TM)  

NSDL National Science Digital Library

NanoKids(TM) is an education and outreach program for intermediate-level (middle-school) students intended to increase their knowledge of nanotechnology and emerging research and technology in this field, which involves working with objects on the molecular and atomic scale (as small as one-billionth of a meter). Site materials include a series of self-contained lessons accompanied by animated videos and an online workbook for students. There is also a sample test and additional resources for teachers (slide presentations, games, and other materials). The site also offers an overview of the project and its participants, biographical "sketches" of the characters used in the animations, and one-page features that explain the nanometer scale, the countries and scientists involved in nanotechnology, and atoms, molecules, and bondng. Some materials on the site are available in Spanish.

253

Detection of a tall ridge at the core-mantle boundary from scattered PKP energy  

NASA Astrophysics Data System (ADS)

The seismic wavefield mainly contains reflected, refracted and direct waves but energy related to elastic scattering can also be identified at frequencies of 1 Hz and higher. The scattered, high-frequency seismic wavefield contains information on the small-scale structure of the Earth's crust, mantle and core. Due to the high thermal conductivity of mantle materials causing rapid dissipation of thermal anomalies, the Earth's small-scale structure most likely reveals details of the composition of the interior, and, is therefore essential for our understanding of the dynamics and evolution of the Earth. Using specific ray configurations we can identify scattered energy originating in the lower mantle and under certain circumstances locate its point of origin in the Earth allowing further insight into the structure of the lowermost mantle. Here we present evidence, from scattered PKP waves, for a heterogeneous structure at the core-mantle boundary (CMB) beneath southern Africa. The structure rises approximately 80 km above the CMB and is located at the eastern edge of the African LLSVP. Mining-related and tectonic seismic events in South Africa, with mb from 3.2 to 6.0 recorded at epicentral distances of 119.3° to 138.8° from Yellowknife Array (YKA) (Canada), show large amplitude precursors to PKPdf arriving 3-15 s prior to the main phase. We use array processing to measure slowness and backazimuth of the scattered energy and determine the scatterer location in the deep Earth. To improve the resolution of the slowness vector at the medium aperture YKA we present a new application of the F-statistic. The high-resolution slowness and backazimuth measurements indicate scattering from a structure up to 80 km tall at the CMB with lateral dimensions of at least 1200 km by 300 km, at the edge of the African Large Low Shear Velocity Province. The forward scattering nature of the PKP probe indicates that this is velocity-type scattering resulting primarily from changes in elastic parameters. The PKP scattering data are in agreement with dynamically supported dense material related to the Large Low Shear Velocity Province.

Frost, Daniel A.; Rost, Sebastian; Selby, Neil D.; Stuart, Graham W.

2013-10-01

254

Road pavers' occupational exposure to asphalt containing waste plastic and tall oil pitch.  

PubMed

Waste plastic (WP) and tall oil pitch (T), which are organic recycled industrial by-products, have been used as a binder with bitumen in stone mastic asphalt (SMA) and asphalt concrete (AC). We compared the exposure over one workday in 16 road pavers participating in a survey at four paving sites, using mixes of conventional asphalt (SMA, AC) or mixes containing waste material (SMA-WPT, AC-WPT). The concentrations of 11 aldehydes in air were 515 and 902 microg m(-3) at the SMA-WPT and AC-WPT worksites, being 3 and 13 times greater than at the corresponding worksites laying conventional asphalt. Resin acids (2-42 microg m(-3)), which are known sensitizers, were detected only during laying of AC-WPT. The emission levels (microg m(-3)) of total particulates (300-500), bitumen fumes (60-160), bitumen vapour (80-1120), naphthalene (0.59-1.2), phenanthrene (0.21-0.32), pyrene (<0.015-0.20), benzo(a)pyrene (<0.01) and the sum of 16 PAHs (polycyclic aromatic hydrocarbons, 1.28-2.00) were similar for conventional and WPT asphalts. The dermal deposition of 16 PAHs on exposure pads (on workers' wrist) was low in all pavers (0.7-3.5 ng cm(-2)). Eight OH-PAH biomarkers of naphthalene, phenanthrene and pyrene exposures were quantified in pre- and post-shift urine specimens. The post-shift concentrations (mean +/- SD, micromol mol(-1) creatinine) of 1- plus 2-naphthol; 1-,2-,3-,4- plus 9-phenanthrol; and 1-hydroxypyrene were, respectively, for asphalt workers: 18.1+/- 8.0, 2.41 +/- 0.71 and 0.66+/- 0.58 (smokers); 6.0+/- 2.3, 1.70+/- 0.72 and 0.27+/- 0.15 (non-smokers); WPT asphalt workers: 22.0+/- 9.2, 2.82+/- 1.11 and 0.76+/- 0.18 (smokers); 6.8+/- 2.6, 2.35+/- 0.69 and 0.46+/- 0.13 (non-smokers). The work-related uptake of PAHs was low in all pavers, although it was significantly greater in smokers than in non-smokers. The WPT asphalt workers complained of eye irritation and sore throat more than the pavers who had a much lower exposure to aldehydes and resin acids. PMID:16395464

Väänänen, Virpi; Elovaara, Eivor; Nykyri, Erkki; Santonen, Tiina; Heikkilä, Pirjo

2006-01-01

255

Tall FIN formation for FINFET devices of 20nm and beyond using multi-cycles of passivation and etch processes  

NASA Astrophysics Data System (ADS)

In the past a few years, there has been a trend that non-planar field effect transistors (FETs) replace planar counterparts in semiconductor industry. One of critical and challenging processes to fabricate this non-planar device in bulk Si wafers is forming the array of tall Si fins with tight pitch that is used for gate channel as well as source and drain. Fin formation process typically involves deep Si etch using hard mask formed by double patterning technique (DPT). Traditional Si etch tends to results in intra-cell depth loading due to pitch walking and necking profile at the top portion of fins due to deep Si etch at small space. In addition, tall fins tend to stick to each other after post etch wet clean due to surface tension and hydrophilic fin sidewall. In this publication, 200nm tall fins with straight profile at the significant top portion of fins are demonstrated by using multi cycles of passivation and etch process. Physical and chemical parameters of each cycle were tuned respectively to generate straight top profile for gate channel control and smooth bottom profile to make it friendly for the following oxide gap fill process. Intra-cell and iso-dense depth loading is less than 3% of total depth. In addition, fin sticking is no longer observed after this multi cycle process. The exact mechanism is still under investigation but it is postulated that the fin sidewall surface condition has changed to be less hydrophilic due to multi cycle passivation.

Choi, Dae-han; Yang, Dae Geun; Khanna, Puneet; Maeng, Chang; Hu, Owen; Shen, Hongliang; Wei, Andy; Kim, Sung

2013-03-01

256

Constriction of bovine vasculature caused by endophyte-infected tall fescue seed extract is similar to pure ergovaline.  

PubMed

Ergovaline has been extensively used to study vasoactive effects of endophyte- (Neotyphodium coenophialum) infected tall fescue (Lolium arundinaceum). However, initial results indicated that an extract of toxic tall fescue seed (E+EXT) is more potent than ergovaline alone in a right ruminal artery and vein bioassay. The E+EXT induced a greater contractile response than an equal concentration of ergovaline alone in the ruminal artery of heifers (P = 0.018). This led to a hypothesis that other compounds in the seed extract contribute to vasoconstriction. Thus, experiments were conducted to determine if vasoactivity of an E+EXT is different from a mixture of ergot alkaloids (ALK; ergovaline, ergotamine, ergocristine, ergocryptine, ergocornine, ergonovine, and lysergic acid) of similar concentrations and to determine if the vasoactivity of an E+EXT differs from an endophyte-free tall fescue seed extract (E-EXT). Segments of lateral saphenous vein and right ruminal artery and vein were collected from Holstein steers (n = 6) shortly after slaughter. Vessels were cleaned of excess connective tissue and fat and sliced into segments that were suspended in a multimyograph chamber with 5 mL of continually oxygenated Krebs-Henseleit buffer, equilibrated for 90 min, and exposed to a reference compound (120 mM KCl for ruminal vessels and 0.1 mM norepinephrine for saphenous vein). Increasing concentrations of each treatment (E+EXT, E-EXT, ALK, and ergovaline) were added to the respective chamber every 15 min after buffer replacement. Data were normalized as a percentage of maximal contractile response of the reference compound and fit to a sigmoidal concentration response curve. Ergovaline, ALK, and E+EXT induced similar responses in the saphenous vein, ruminal artery, and ruminal vein. The E+EXT displayed a smaller EC(50) (half maximal effective concentration) than ergovaline or ALK in the saphenous vein and ruminal vein (P < 0.008), but not the ruminal artery (P = 0.31). Extrapolated maximum response was greatest in the saphenous vein for ergovaline, least for E+EXT, and intermediate for ALK (P < 0.0001). The E-EXT did not induce a contractile response in any vessel tested (P > 0.1). Data from this study indicate that ergovaline is largely responsible for the locally induced vasoconstriction of bovine vasculature observed with endophyte-infected tall fescue. PMID:22147482

Foote, A P; Harmon, D L; Brown, K R; Strickland, J R; McLeod, K R; Bush, L P; Klotz, J L

2012-05-01

257

Characterization of Fructan from Mature Leaf Blades and Elongation Zones of Developing Leaf Blades of Wheat, Tall Fescue, and Timothy 1  

PubMed Central

Water-soluble carbohydrate composition of mature (ceased expanding) leaf blades and the elongation zone of developing leaf blades was characterized in wheat (Triticum aestivum L.), tall fescue (Festuca arundinacea Schreb.), and timothy (Phleum pratense L.). These species were chosen because they differ in mean degree of polymerization (DP) of fructan in the mature leaf blade. Our objective was to compare the nature and DP of the fructan. Vegetative plants were grown with a 14-hour photoperiod and constant 21°C at the leaf base. Gel permeation chromatography of leaf blade extracts showed that the apparent mean fructan DP increased in the order wheat < tall fescue < timothy. Apparent mean DP of elongation zone fructan was higher than that of leaf blade fructan in wheat and timothy, but the reverse occurred for tall fescue. Low DP (?10) and high DP (>10) pools were found in both tissues of tall fescue and wheat, but concentration of low DP fructan was very low in either tissue of timothy. All three species have high DP fructan. Comigration with standards on thin-layer chromotography showed that wheat contained 1-kestose and a noninulin fructan oligomer series. Tall fescue contained neokestose, 1-kestose and higher oligosaccharides that comigrated with neokestose-based compounds and inulins. Thin-layer chromatography showed that small amounts of fructose-containing oligosaccharides were present in timothy. Images Fig. 2 Fig. 3

Spollen, William G.; Nelson, Curtis J.

1988-01-01

258

KPT-330 inhibitor of CRM1 (XPO1)-mediated nuclear export has selective anti-leukaemic activity in preclinical models of T-ALL and AML  

PubMed Central

Summary This study explored the anti-leukaemic efficacy of novel irreversible inhibitors of the major nuclear export receptor, chromosome region maintenance 1 (CRM1, also termed XPO1). We found that these novel CRM1 antagonists, termed SINE (Selective Inhibitors of Nuclear Export), induced rapid apoptosis at low nanomolar concentrations in a panel of 14 human T-cell acute lymphoblastic leukaemia (T-ALL) cell lines representing different molecular subtypes of the disease. To assess in vivo anti-leukaemia cell activity, we engrafted immunodeficient mice intravenously with the human T-ALL MOLT-4 cells, which harbour activating mutations of NOTCH1 and NRAS as well as loss of function of the CDKN2A, PTEN and TP53 tumour suppressors and express a high level of oncogenic transcription factor TAL1. Importantly, we examined the in vivo anti-leukaemic efficacy of the clinical SINE compound KPT-330 against TALL and acute myeloid leukaemia (AML) cells. These studies demonstrated striking in vivo activity of KPT-330 against T-ALL and AML cells, with little toxicity to normal murine haematopoietic cells. Taken together, our results show that SINE CRM1 antagonists represent promising “first-in-class” drugs with a novel mechanism of action and wide therapeutic index, and imply that drugs of this class show promise for the targeted therapy of T-ALL and AML.

Etchin, Julia; Sanda, Takaomi; Mansour, Marc R.; Kentsis, Alex; Montero, Joan; Le, Bonnie T.; Christie, Amanda L.; McCauley, Dilara; Rodig, Scott J.; Kauffman, Michael; Shacham, Sharon; Stone, Richard; Letai, Anthony; Kung, Andrew L.; Look, A. Thomas

2013-01-01

259

Probing the magnetization reversal process of permalloy nano-rings with high wall height-to-thickness ratios  

NASA Astrophysics Data System (ADS)

We report a study of magnetization reversal process on a tall magnetic nano-ring with a wall height-to-thickness ratio of up to 21. Samples in a hexagonal lattice pattern of ring array with an outer/inner diameter of 300/260 nm and a ring height of 420 nm are fabricated using electron beam lithography in conjunction with an ion beam etching technique. A longitudinal magneto-optical Kerr effect (MOKE) measurement reveals that meta-stable states exist during the magnetization reversal process. In particular, the exact magnetization configurations at the top end of the nano-ring are illustrated using magnetic force microscopy (MFM) that is facilitated with a photoresist etch-back technique. Most interestingly, MFM images of two sets of head-to-head (H2H)/tail-to-tail (T2T) domain walls are captured during the magnetization reversal process. It is believed that the domain walls formation and evolution processes at the top end of the nano-ring are mediated by the anti-symmetrical distribution of the vortex domain wall on the tubular sidewalls. Simulation results using Object Oriented Micromagnetic Framework confirm the MOKE hysteresis loop and MFM imaging.

Chao, C. T.; Huang, Y. C.; Kuo, C. Y.; Horng, Lance; Wu, J. C.

2013-05-01

260

3D nano-structures for laser nano-manipulation  

PubMed Central

Summary The resputtering of gold films from nano-holes defined in a sacrificial PMMA mask, which was made by electron beam lithography, was carried out with a dry plasma etching tool in order to form well-like structures with a high aspect ratio (height/width ? 3–4) at the rims of the nano-holes. The extraordinary transmission through the patterns of such nano-wells was investigated experimentally and numerically. By doing numerical simulations of 50-nm and 100-nm diameter polystyrene beads in water and air, we show the potential of such patterns for self-induced back-action (SIBA) trapping. The best trapping conditions were found to be a trapping force of 2 pN/W/?m2 (numerical result) exerted on a 50-nm diameter bead in water. The simulations were based on the analytical Lorentz force model.

Seniutinas, Gediminas; Gervinskas, Gediminas; Brasselet, Etienne; Juodkazis, Saulius

2013-01-01

261

3D nano-structures for laser nano-manipulation.  

PubMed

The resputtering of gold films from nano-holes defined in a sacrificial PMMA mask, which was made by electron beam lithography, was carried out with a dry plasma etching tool in order to form well-like structures with a high aspect ratio (height/width ? 3-4) at the rims of the nano-holes. The extraordinary transmission through the patterns of such nano-wells was investigated experimentally and numerically. By doing numerical simulations of 50-nm and 100-nm diameter polystyrene beads in water and air, we show the potential of such patterns for self-induced back-action (SIBA) trapping. The best trapping conditions were found to be a trapping force of 2 pN/W/?m(2) (numerical result) exerted on a 50-nm diameter bead in water. The simulations were based on the analytical Lorentz force model. PMID:24062979

Seniutinas, Gediminas; Rosa, Lorenzo; Gervinskas, Gediminas; Brasselet, Etienne; Juodkazis, Saulius

2013-01-01

262

Folded Conformation, Cyclic Pentamer, Nano-Structure and PAD4 Binding Mode of YW3-56  

PubMed Central

The physical and chemical mechanisms of small molecules with pharmacological activity forming nano-structures are developing into a new field of nano-medicine. By using ROESY 2D NMR spectroscopy, trandem mass spectroscopy, transmission electron microscopy and computer-assisted molecular modeling, this paper demonstrated the contribution of the folded conformation, the intra- and intermolecular ?-? stacking, the intra- and intermolecular hydrogen bonds, and the receptor binding free energy of 6-dimethylaminonaph-2-yl-{N-S-[1-benzylcarba-moyl-4-(2-chloroacetamidobutyl)]-carboxamide (YW3-56) to the rapid formation of nano-rings and the slow formation of nano-capsules. Thus we have developed a strategy that makes it possible to elucidate the physical and chemical mechanisms of bioactive small molecules forming nano-structures.

Zhu, Haimei; Wang, Yuji; Wang, Yaonan; Zhao, Shurui; Zhao, Ming; Gui, Lin; Xu, Wenyun; Chen, Xiangyun Amy; Wang, Yanming; Peng, Shiqi

2013-01-01

263

Oncogenic NOTCH1 control of MYC and PI3K: challenges and opportunities for anti-NOTCH1 therapy in T-ALL  

PubMed Central

The identification of activating mutations in NOTCH1 in the majority of T-cell acute lymphoblastic leukemias and lymphomas (T-ALL) has brought much interest in inhibiting NOTCH1 signaling as therapeutic target in this disease. Small molecule inhibitors of the ?-secretase complex, which mediates a critical proteolytic cleavage required for NOTCH1 activation, hold the promise of becoming an effective molecular therapy against relapsed and refractory T-ALL. Recent progress in the elucidation of the transcriptional regulatory networks downstream of oncogenic NOTCH1 has uncovered a central role of NOTCH1 signaling in promoting leukemic cell growth and revealed an intricate circuitry that connects NOTCH1 signaling with MYC and the PI3K-AKT signaling pathway. The identification of the downstream effector pathways controlled by NOTCH1 should pave the way for the rational design of anti-NOTCH1 therapies for the treatment of T-ALL.

Palomero, Teresa; Ferrando, Adolfo

2008-01-01

264

Epigenetic regulation of the Ink4a-Arf (Cdkn2a) tumor suppressor locus in the initiation and progression of Notch1 driven T-ALL  

PubMed Central

Activating mutations of NOTCH1 and deletion of the INK4A-ARF (CDKN2A) tumor suppressor locus are two of the most frequent genetic alterations in T cell acute lymphoblastic leukemia (T-ALL). In a murine model of T-ALL induced by the intracellular domain of Notch1 (ICN1), the genetic interaction between ICN1 signaling and Arf inactivation is developmentally stage-specific, with a more pronounced requirement for Arf deletion in thymocytes than in bone marrow precursors targeted for transformation. In the thymus, the target cell for transformation is a CD4 and CD8 double-negative progenitor that undergoes T cell receptor beta chain rearrangement, a cell type in which polycomb silencing of Ink4a-Arf is normally requisite. Epigenetic remodeling during tumor progression licenses Arf as a tumor suppressor and in turn provides the selective pressure for Ink4a-Arf deletion in clonal T-ALLs that emerge.

Volanakis, Emmanuel J.; Boothby, Mark R.; Sherr, Charles J.

2013-01-01

265

Nano Science and Technology Institute  

NSDL National Science Digital Library

The Nano Science and Technology Institute (NSTI) is chartered with the promotion and integration of nano and other advanced technologies through education, technology and business development. NSTI accomplishes this mission through its offerings of membership services, continuing education programs, scientific and business publishing and community outreach. NSTI produces the annual Nanotech conference and trade show, the most comprehensive international nanotechnology convention in the world. NSTI also produces the semi-annual Nanotech Venture, Nanotech Industrial Impact Workshop, Nano Impact Summit and the Nanotech Course Series in the US and Europe. NSTI was founded in 1997 as a result of the merger between various scientific societies, and is headquartered in Cambridge, Massachusetts with additional offices in California and Switzerland.

2008-12-03

266

Vacuum nano-hole array embedded organic light emitting diodes.  

PubMed

We demonstrated a nano-hole array (NHA) embedded structure that was fabricated for organic light emitting diodes (OLEDs) using a robust reverse transfer process. The NHA structure is proposed in this study as a strategy for maximizing the diffraction strength of two dimensional photonic crystals (PCs) by engineering vacuum nano-holes inside a dielectric slab. The electroluminescence (EL) intensity of the OLED was improved by more than twice. Such an optical enhancement was evaluated by using the angular dependence of photoluminescence (PL). The FDTD simulation was carried out to optimize the NHA structure for extraction of the emission induced from both vertical and horizontal dipoles. We explored the effect of the NHA structure on the extraction improvement converted from waveguide mode by measuring EL intensities of the devices with a hemisphere lens. In addition, the transfer process employed in this study yielded extremely low surface roughness, and thus outstanding electrical characteristics. PMID:24336917

Jeon, Sohee; Jeong, Jun-ho; Song, Young Seok; Jeong, Won-Ik; Kim, Jang-Joo; Youn, Jae Ryoun

2014-03-01

267

Plasmasynthesized nano-aluminum powders  

Microsoft Academic Search

The plasma electro-condensation\\u000a process was used to synthesize nano-sized aluminum powders. Adding different\\u000a chemicals modified the physical and chemical properties of these powders.\\u000a To characterize the nano-sized powders, X-ray diffraction, TEM, BET analyses,\\u000a and simultaneous TG\\/DSC analyses were performed. TG\\/DSC analyses revealed\\u000a a dramatic degradation of the aluminum oxide layer after storage of the aluminum\\u000a powder in air for a

Alla Pivkina; D. Ivanov; Yu. Frolov; Svetlana Mudretsova; Anna Nickolskaya; J. Schoonman

2006-01-01

268

The E-cadherin-repressed hNanos1 gene induces tumor cell invasion by upregulating MT1-MMP expression.  

PubMed

In this study, we examined the role of the E-cadherin-repressed gene human Nanos1 (hNanos1) in tumor invasion process. First, our in vivo study revealed that hNanos1 mRNAs were overexpressed in invasive lung carcinomas. Moreover, hNanos1 was co-localized with MT1-MMP (membrane type 1-matrix metalloproteinase) in E-cadherin-negative invasive lung tumor clusters. Using an inducible Tet-on system, we showed that induction of hNanos1 expression in DLD1 cells increased their migratory and invasive abilities in a three-dimensional migration and in a modified Boyden chamber assay. Accordingly, we demonstrated that hNanos1 upregulated MT1-MMP expression at the mRNA and protein levels. Inversely, using an RNA interference strategy to inhibit hNanos1 expression in invasive Hs578T, BT549 and BZR cancer cells, we observed a downregulation of MT1-MMP mRNA and protein and concomitantly a decrease of the invasive capacities of tumor cells in a modified Boyden chamber assay. Taken together, our results demonstrate that hNanos1, by regulating MT1-MMP expression, plays an important role in the acquisition of invasive properties by epithelial tumor cells. PMID:18223680

Bonnomet, A; Polette, M; Strumane, K; Gilles, C; Dalstein, V; Kileztky, C; Berx, G; van Roy, F; Birembaut, P; Nawrocki-Raby, B

2008-06-12

269

Convergence of goals: phylogenetical, morphological, and physiological characterization of tolerance to drought stress in tall fescue (Festuca arundinacea Schreb.).  

PubMed

The aim of this study is to find Iranian tall fescue accessions that tolerate drought stress and investigation on phylogenetical, morphological, and physiological characterization of them. For this propose, inter-simple sequence repeats (ISSR) markers were used to examine the genetic variability of accessions from different provinces of Iran. Of 21 primers, 20 primers generated highly reproducible fragments. Using these primers, 390 discernible DNA fragments were produced with 367 (93.95 %) being polymorphic. The polymorphic information content (PIC) values ranged from 0.948 to 0.976, with a mean PIC value of 0.969. Probability identity (PI) and discriminating power (D = 1-PI) among the primers ranged from 0.001 to 0.004 and 0.998 to 0.995, respectively. A binary qualitative data matrix was constructed. Data analyses were performed using the NTSYS software and the similarity values were used to generate a dendrogram via UPGMA. To study the drought stress, plants were irrigated at 25 % FC condition for three times. Fresh leaves were collected to measure physiological characters including: superoxide dismutase, catalase, and peroxidase activities and proline and total chlorophyll content at two times, before and after stress application. Relative water content, fresh and dry weight ratio, survival percentage, and visual quality were evaluated after stress. Morphological and physiological characters were assessed in order to classify accessions as either tolerant or sensitive using Ward's method of Hierarchical cluster analysis in SPSS software. The results of present study demonstrated that the ISSR markers are useful for studying tall fescue genetic diversity. Convergence of morphological and physiological characterizations during drought stress and phylogenetic relationship results showed that accessions can be grouped into four clusters; drought-tolerant accessions that collected from west of Iran, drought-tolerant accessions collected from northwest of Iran, drought semi-tolerant accessions collected from center of Iran, and drought-sensitive accessions collected from north of Iran. Data presented could be used to classify the tall fescue accessions based on suitability of cultivation in the regions studied or the regions with the similar environmental condition. PMID:24078217

Salehi, Mohammadreza; Salehi, Hassan; xNiazi, Hassan; Ghobadi, Cyrus

2014-03-01

270

Nano wires by self assembly  

Microsoft Academic Search

We present a technique to fabricate nano wires on silicon substrates without any lithography. The wires are 50 nm or less in width, but their lengths can be 10 s of micro meters. They can be formed by a single or multiple layers of metals. The wires can be designed to form a network which can be partially released from

Taher Saif; Erdem Alaca; Huseyin Sehitoglu

2003-01-01

271

Alterations in serotonin receptor-induced contractility of bovine lateral saphenous vein in cattle grazing endophyte-infected tall fescue.  

PubMed

As part of a 2-yr study documenting the physiologic impact of grazing endophyte-infected tall fescue on growing cattle, 2 experiments were conducted to characterize and evaluate effects of grazing 2 levels of toxic endophyte-infected tall fescue pastures on vascular contractility and serotonin receptors. Experiment 1 examined vasoconstrictive activities of 5-hydroxytryptamine (5HT), ?-methylserotonin (ME5HT; a 5HT(2) receptor agonist), d-lysergic acid (LSA), and ergovaline (ERV) on lateral saphenous veins collected from steers immediately removed from a high-endophyte-infected tall fescue pasture (HE) or a low-endophyte-infected mixed-grass (LE) pasture. Using the same pastures, Exp. 2 evaluated effects of grazing 2 levels of toxic endophyte-infected tall fescue on vasoconstrictive activities of (±)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI), BW 723C86 (BW7), CGS-12066A (CGS), and 5-carboxamidotryptamine hemiethanolate maleate (5CT), agonists for 5HT(2A),( 2B), 5HT(1B), and 5HT(7) receptors, respectively. One-half of the steers in Exp. 2 were slaughtered immediately after removal from pasture, and the other one-half were fed finishing diets for >91 d before slaughter. For Exp. 1, maximal contractile intensities were greater (P < 0.05) for steers grazing LE pastures than HE pastures for 5HT (73.3 vs. 48.9 ± 2.1%), ME5HT (52.7 vs. 24.9 ± 1.5%), and ERV (65.7 vs. 49.1 ± 2.6%). Onset of contractile response did not differ for 5HT (P = 0.26) and ERV (P = 0.93), but onset of ME5HT contraction was not initiated (P < 0.05) in HE steers until 10(-4) compared with 10(-5) M in LE-grazing steers. For Exp. 2, maximal contractile intensities achieved with DOI were 35% less (P < 0.05), whereas those achieved with 5CT were 37% greater (P < 0.05), in steers grazing HE pastures. Contractile response to CGS did not differ between pasture groups, and there was an absence of contractile response to BW7 in both groups. There were no differences between endophyte content in contractile responses after animals were finished for >91 d. Experiment 1 demonstrated that grazing of HE pastures for 89 to 105 d induces functional alterations in blood vessels, as evidenced by reduced contractile capacity and altered serotonergic receptor activity. Experiment 2 demonstrated that grazing HE pastures alters vascular responses, which may be mediated through altered serotonin receptor activities, and these alterations may be ameliorated by the removal of ergot alkaloid exposure as demonstrated by the absence of differences in finished steers. PMID:22274863

Klotz, J L; Brown, K R; Xue, Y; Matthews, J C; Boling, J A; Burris, W R; Bush, L P; Strickland, J R

2012-02-01

272

Comparison of ground and satellite based measurements of the fraction of photosynthetically active radiation intercepted by tall-grass prairie  

NASA Technical Reports Server (NTRS)

The fraction, of photosynthetically active radiation absorbed by vegetation, F sub ipar, is an important requirement for estimating vegetation biomass productivity and related quantities. This was an integral part of a large international effort; the First ISLSCP Field Experiment (FIFE). The main objective of FIFE was to study the effects of vegetation on the land atmosphere interactions and to determine if these interactions can be assessed from satellite spectral measurements. The specific purpose of this experiment was to find out how well measurements of F sub ipar relate to ground, helicopter, and satellite based spectral reflectance measurements. Concurrent measurements of F sub ipar and ground, helicopter, and satellite based measurements were taken at 13 tall grass prairie sites in Kansas. The sites were subjected to various combinations of burning and grazing managements.

Demetriades-Shah, T. H.; Kanemasu, E. T.; Flitcroft, I.; Su, H.

1990-01-01

273

Evaluation and comparison of dominant backscattering sources at 10 GHz in two treatments of tall-grass prairie  

NASA Technical Reports Server (NTRS)

A very-fine-range resolution Frequency Modulated-Continuous Wave radar, operating at X-band, was used to evaluate the primary backscattering contributors to the radar signal from a tall-grass prairie. Defoliation was used to help measure relative backscatter from various components of the canopy with both linear polarizations and at 30 deg and 50 deg incidence angles. Variation of the average returned power with incidence angle was greatest for the natural prairie at horizontal polarization and was the least for vertical polarization. Vertical polarization seemed to be more sensitive to the upper portions of the plants, whereas horizontal polarization was to the lower portions. Attenuation for horizontal polarization was only half that for vertical polarization. Dielectric measurements of the grass and some of the canopy components were conducted as well.

Zoughi, Reza; Bredow, J.; Moore, R. K.

1987-01-01

274

[Genetic variability of juniper tall (Juniperus excelsa Bieb.) in the northern and southern limits of the natural distribution].  

PubMed

Genetic structure, subdivision and differentiation of six populations of juniper tall (Juniperus excelsa Bieb.) of the Crimean Mountains and of one population in Lebanon were investigated using 18 polymorphic allozyme loci as genetic markers. The high level of genetic variability of J. excelsa was established in the northern and the southern limits of its natural habitat. The mean values of the main indicators of genetic polymorphism were: P99 = 1,000, A = 3,167, H(E) = 0,370, H(o) = 0,405. Subdivision and differentiation of populations were low (F(ST) = 0,032, D(N) = 0,026) indicating similarity of their gene pools. PMID:23821952

Korshikov, I I; Nikolaeva, A V

2013-01-01

275

A Novel Homozygous Mutation in FGFR3 Causes Tall Stature, Severe Lateral Tibial Deviation, Scoliosis, Hearing Impairment, Camptodactyly, and Arachnodactyly.  

PubMed

Most reported mutations in the FGFR3 gene are dominant activating mutations that cause a variety of short-limbed bone dysplasias including achondroplasia and syndromic craniosynostosis. We report the phenotype and underlying molecular abnormality in two brothers, born to first cousin parents. The clinical picture is characterized by tall stature and severe skeletal abnormalities leading to inability to walk, with camptodactyly, arachnodactyly, and scoliosis. Whole exome sequencing revealed a homozygous novel missense mutation in the FGFR3 gene in exon 12 (NM_000142.4:c.1637C>A: p.(Thr546Lys)). The variant is found in the kinase domain of the protein and is predicted to be pathogenic. It is located near a known hotspot for hypochondroplasia. This is the first report of a homozygous loss-of-function mutation in FGFR3 in human that results in a skeletal overgrowth syndrome. PMID:24864036

Makrythanasis, Periklis; Temtamy, Samia; Aglan, Mona S; Otaify, Ghada A; Hamamy, Hanan; Antonarakis, Stylianos E

2014-08-01

276

Secondary cell wall deposition causes radial growth of fibre cells in the maturation zone of elongating tall fescue leaf blades.  

PubMed

A gradient of development consisting of successive zones of cell division, cell elongation and cell maturation occurs along the longitudinal axis of elongating leaf blades of tall fescue (Festuca arundinacea Schreb.), a C3 grass. An increase in specific leaf weight (SLW; dry weight per unit leaf area) in the maturation region has been hypothesized to result from deposition of secondary cell walls in structural tissues. Our objective was to measure the transverse cell wall area (CWA) associated with the increase in SLW, which occurs following the cessation of leaf blade elongation at about 25 mm distal to the ligule. Digital image analysis of transverse sections at 5, 15, 45, 75 and 105 mm distal to the ligule was used to determine cell number, cell area and protoplast area of structural tissues, namely fibre bundles, mestome sheaths and xylem vessel elements, along the developmental gradient. Cell diameter, protoplast diameter and area, and cell wall thickness and area of fibre bundle cells were calculated from these data. CWA of structural tissues increased in sections up to 75 mm distal to the ligule, confirming the role of cell wall deposition in the increase in SLW (r2 = 0.924; P < or = 0.01). However, protoplast diameter of fibre cells did not decrease significantly as CWA increased, although mean thickness of fibre cell walls increased by 95 % between 15 and 105 mm distal to the ligule. Therefore, secondary cell wall deposition in fibre bundles of tall fescue leaf blades resulted in continued radial expansion of fibre cells rather than in a decrease in protoplast diameter. PMID:12096823

Macadam, Jennifer W; Nelson, Curtis J

2002-01-01

277

The spectral shift between near- and far-field resonances of optical nano-antennas.  

PubMed

Within the past several years a tremendous progress regarding optical nano-antennas could be witnessed. It is one purpose of optical nano-antennas to resonantly enhance light-matter interactions at the nanoscale, e.g. the interaction of an external illumination with molecules. In this specific, but in almost all schemes that take advantage of resonantly enhanced electromagnetic fields in the vicinity of nano-antennas, the precise knowledge of the spectral position of resonances is of paramount importance to fully exploit their beneficial effects. Thus far, however, many nano-antennas were only optimized with respect to their far-field characteristics, i.e. in terms of their scattering or extinction cross sections. Although being an emerging feature in many numerical simulations, it was only recently fully appreciated that there exists a subtle but very important difference in the spectral position of resonances in the near-and the far-field. With the purpose to quantify this shift, Zuloaga et al. suggested a Lorentzian model to estimate the resonance shift. Here, we devise on fully analytical grounds a strategy to predict the resonance in the near-field directly from that in the far-field and disclose that the issue is involved and multifaceted, in general. We outline the limitations of our theory if more sophisticated optical nano-antennas are considered where higher order multipolar contributions and higher order antenna resonances become increasingly important. Both aspects are highlighted by numerically studying relevant nano-antennas. PMID:24787879

Menzel, Christoph; Hebestreit, Erik; Mühlig, Stefan; Rockstuhl, Carsten; Burger, Sven; Lederer, Falk; Pertsch, Thomas

2014-04-21

278

Looking back in time: conducting a cohort study of the long-term effects of treatment of adolescent tall girls with synthetic hormones  

PubMed Central

Objective Public health research is an endeavour that often involves multiple relationships, far-reaching collaborations, divergent expectations and various outcomes. Using the Tall Girls Study as a case study, this paper will present and discuss a number of methodological, ethical and legal challenges that have implications for other public health research. Approach The Tall Girls Study was the first study to examine the long-term health and psychosocial effects of oestrogen treatment for tall stature. Results In undertaking this study the research team overcame many hurdles: in maintaining collaboration with treating clinicians and with the women they had treated as girls - groups with opposing points of view and different expectations; using private practice medical records to trace women who had been patients up to forty years earlier; and exploring potential legal issues arising from the collection of data related to treatment. Conclusion While faced with complex challenges, the Tall Girls Study demonstrated that forward planning, ongoing dialogue between all stakeholders, transparency of processes, and the strict adherence to group-developed protocols were keys to maintaining rigour while undertaking pragmatic research. Implications Public health research often occurs within political and social contexts that need to be considered in the planning and conduct of studies. The quality and acceptability of research findings is enhanced when stakeholders are engaged in all aspects of the research process.

2011-01-01

279

Decrements in Children's Reponses to "Big" and "Tall": A Reconsideration of the Potential Cognitive and Semantic Causes. Kansas Working Papers in Linguistics, Vol. 5, No. 2.  

ERIC Educational Resources Information Center

A decline exists in children's ability at ages 4 and 5 to accurately respond to the difference between polar adjectives such as "big" and "tall.""Taller" and "bigger" are both taken to mean "having a higher top point," rather than "bigger" meaning "greater overall mass." Two hypotheses are put forth to explain this. The "strong cognitive…

Gathercole, Virginia C. Mueller

280

46 CFR 32.55-20 - Venting of cargo tanks of tankships constructed on or after July 1, 1951-T/ALL.  

Code of Federal Regulations, 2013 CFR

...tankships constructed on or after July 1, 1951-T/ALL. 32.55-20 Section 32.55-20 Shipping...tankships constructed on or after July 1, 1951âT/ALL. (a) Venting required. (1) On all tankships, the construction or...

2013-10-01

281

46 CFR 32.55-50 - Ventilation of tankships that have a keel laying date on or after January 1, 1975-T/ALL.  

Code of Federal Regulations, 2013 CFR

...tankships that have a keel laying date on or after January 1, 1975-T/ALL. 32.55-50 Section 32.55-50 Shipping COAST...tankships that have a keel laying date on or after January 1, 1975âT/ALL. Each tankship that has a keel laying date on...

2013-10-01

282

Environmental Impact Research Program: Tall Wheatgrass (Agropyron elongatum). Section 7.1.3. US Army Corps of Engineers Wildlife Resources Management Manual.  

National Technical Information Service (NTIS)

A plant materials report on tall wheatgrass (Agropyron elongatum) is provided as Section 7.1.3 of the US Army Corps of Engineers Wildlife Resources Management Manual. The report was prepared as a guide to assist the Corps District or project biologist wit...

C. H. Wasser P. L. Dittberner D. R. Dietz

1986-01-01

283

Effects of modified tall oil and creatine monohydrate on growth performance, carcass characteristics, and meat quality of growing-finishing pigs1,2  

Microsoft Academic Search

The effects of feeding modified tall oil (MTO) and creatine monohydrate (CMH) on growing- finishing pig growth performance, carcass characteris- tics, and meat quality were determined. Eighty cross- bred barrows (initially 45.4 kg) were allotted randomly to one of four dietary treatments by weight and ances- try. The experiment was arranged as a 2 × 2 factorial with two levels

P. R. O'Quinn; B. S. Andrews; R. D. Goodband; J. A. Unruh; J. L. Nelssen; J. C. Woodworth; M. D. Tokach; K. Q. Owen

284

Effects of selected endophyte and tall fescue cultivar combinations on steer grazing performance, indicators of fescue toxicosis, feedlot performance, and carcass traits.  

PubMed

Five tall fescue [Lolium arundinaceum (Schreb.)] pastures [wild-type 'Kentucky-31' with 78.0% of plants infected with ergot alkaloid-producing endophyte Neotyphodium coenophialum (KY31 E+), 'Jesup' AR542 endophyte-infected contaminated with 30.3% tall fescue containing ergot alkaloid producing-endophyte (Jesup AR542 E+); 'GA-186' AR584 endophyte-infected contaminated with 11.8% tall fescue containing ergot alkaloid producing-endophyte (AGRFA 140); 'PDF' AR584 endophyte-infected contaminated with 5.5% tall fescue containing ergot alkaloid producing-endophyte (AGRFA 144); and 'KYFA 9301' AR584 endophyte-infected contaminated with 10.0% tall fescue containing ergot alkaloid producing-endophyte (AGRFA 150)] were compared for steer growth performance, toxicity, feedlot performance, and carcass traits. Steers (mean initial BW=322 kg) grazed pastures for 84 d in spring and 56 d in autumn for 2 yr. Steers were shipped after grazing in Prairie, MS, to Macedonia, IA, for finishing. Mean herbage mass was not different (P=0.15) among pastures. Posttreatment (d 28+) serum prolactin concentrations were depressed (P=0.013) on KY31 E+. Steers grazing KY31 E+ had greater (P<0.01) posttreatment rectal temperatures during spring. Spring hair coat scores were greatest (P<0.01) on KY31 E+ at d 56 and 84. Steer ADG was least (P<0.01) on KY31 E+ in spring and depressed (P=0.014) on KY31 E+ and Jesup AR542 E+ in autumn. Spring grazing ADG was greater (P=0.049) on AGRFA 150 than Jesup AR542 E+ and AGRFA 140. No BW differences (P=0.09) among pastures were seen at reimplant during feedlot finishing. Pasture had no effect on ADG after reimplant (P=0.68), days on feed (P=0.56), or final BW (P=0.55). Exposure to fescue toxicosis did not affect (P?0.19) carcass traits. Hair coat price discounts applied for spring-grazed steers on KY-31 E+ affected (P<0.01) initial steer monetary values. There were no pasture differences for finishing costs (P?0.61) or final carcass value (P=0.59). Elite tall fescue cultivar and novel endophyte combinations improve growth performance of grazing calves over KY31 E+. Producers whose calves graze KY-31 E+ tall fescue should consider retaining ownership of these cattle through feedlot finishing to avoid market discounts and capture value from compensatory BW gains during finishing. PMID:23048138

Parish, J A; Parish, J R; Best, T F; Boland, H T; Young, C A

2013-01-01

285

Synthesis of gold nano-wire and nano-dumbbell shaped colloids and AuC 60 nano-clusters  

Microsoft Academic Search

A technique for the fabrication of colloidal gold nano-wire and nano-dumbbell shaped particles using rod shaped viruses as\\u000a templates is described. The gold (Au) encapsulation process was accomplished by the precipitation of gold chloride from aqueous\\u000a solutions. When this process was conducted in the presence of C60, small nano-cluster composites of AuC60 formed.

Preston B. Landon; Cody L. Gilleland; Jennifer Synowczynski; Samuel G. Hirsch; R. Glosser

2007-01-01

286

Micro/Nano Processing Technology  

NSDL National Science Digital Library

This course introduces the theory and technology of micro/nano fabrication. Lectures and laboratory sessions focus on basic processing techniques such as diffusion, oxidation, photolithography, chemical vapor deposition, and more. Through team lab assignments, students are expected to gain an understanding of these processing techniques, and how they are applied in concert to device fabrication. Students enrolled in this course have a unique opportunity to fashion and test micro/nano-devices, using modern techniques and technology.This course features detailed lecture slides in the lecture notes section, along with other lab materials used by students in the course in the labs section. In addition, problem sets with solutions are also provided in the assignments section.

Ruff, Susan; Schmidt, Martin

2008-11-13

287

3-D nano-fiber manufacturing by controlled pulling of liquid polymers using nano-probes  

Microsoft Academic Search

In-addition to the applications of imaging and characterization, proximal probes are proposed to be used three-dimensional (3-D) nano-scale manufacturing tools in this paper. Commercially available Atomic Force Microscope (AFM) systems are mainly limited to 1-D or 2-D manipulation tasks, and advanced 3-D nano-manufacturing applications are not possible. Therefore, this paper proposes 3-D nano-scale manipulation of liquid polymer nano-fibers by using

Amrinder S. Naint; Metin Sittit

2003-01-01

288

InterNano: Nanomanufacturing Clearinghouse  

NSDL National Science Digital Library

The National Nanomanufacturing Network (NNN) is an open network for collaboration and information exchange among the nanomanufacturing research, development, and education community. The NNN is an alliance of academic, government and industry partners that cooperate to advance nanomanufacturing strength in the U.S. The NNN conducts strategic workshops and other activities to build communities of practice in nanomanufacturing. The NNN hosts InterNano, the open source information clearinghouse, to provide vital information to nanomanufacturing community.

2011-06-06

289

Broadband monopole optical nano-antennas  

NASA Astrophysics Data System (ADS)

In this paper, a novel design of broadband monopole optical nano-antennas is proposed. It consists of a corrugated halfelliptical patch inside an elliptical aperture. Full-wave electromagnetic simulations have been used to investigate the performance of the nano-antenna. The predicted performance of the proposed monopole nano-antenna is remarkably broadband. Moreover, the proposed broadband nano-antenna can respond to light waves with different polarizations. The proposed optical antenna will pave the way towards the development of high performance optical antennas and optical systems.

Zhou, Rongguo; Ding, Jun; Arigong, Bayaner; Lin, Yuankun; Zhang, Hualiang

2014-03-01

290

A new method for nano-tube imogolite synthesis  

Microsoft Academic Search

The discovery of carbon nano-tube and fullerene nano-ball has accelerated rapid development in the field of nano-scale materials. Imogolite is nano-sized aluminum silicate with tubular morphology that exist in various soil environments and has been already found in the soil environment long before carbon nano-tube was discovered. However, development in research of imogolite is still stagnant compared to other nano-materials.

Z. Abidin; N. Matsue; T. Henmi

2007-01-01

291

Optimum testing intervals of building emergency power supply systems in tall buildings in the Hong Kong Special Administrative Region  

NASA Astrophysics Data System (ADS)

The main objective of this study is to develop a model for the determination of optimum testing interval (OTI) of non-redundant standby plants. This study focuses on the emergency power generators in tall buildings in Hong Kong. The model for the reliability, which is developed, is applicable to any non-duplicated standby plant. In a tall building, the mobilisation of occupants is constrained by its height and the building internal layout. Occupant's safety, amongst other safety considerations, highly depends on the reliability of the fire detection and protection system, which in turn is dependent on the reliability of the emergency power generation plants. A thorough literature survey shows that the practice used in determining OTI in nuclear plants is generally applicable. Historically, the OTI in these plants is determined by balancing the testing downtime and reliability gained from frequent testing. However, testing downtime does not exist in plants like emergency power generator. Subsequently, sophisticated models have taken repairing downtime into consideration. In this study, the algorithms for the determination of OTI, and hence reliability of standby plants, are reconsidered. A new concept is introduced into the subject. A new model is developed for such purposes which embraces more realistic factors found in practice. System aging and the finite life cycle of the standby plant are considered. Somewhat more pragmatic is that the Optimum Overhauling Interval can also be determined from this new model. System unavailability grow with time, but can be reset by test or overhaul. Contrary to fixed testing intervals, OTI is determined whenever system point unavailability exceeds certain level, which depends on the reliability requirement of the standby system. An optimum testing plan for lowering this level to the 'minimum useful unavailability' level (see section 9.1 for more elaboration) can be determined by the new model presented. Cost effectiveness is accounted for by a new parameter 'tau min', the minimum testing interval (MTI). The MTI optimises the total number of tests and the total number of overhauls, when the costs for each are available. The model sets up criteria for test and overhaul and to 'announce' end of system life. The usefulness of the model is validated by a detailed analysis of the operating parameters from 8,500 maintenance records collected for emergency power generation plants in high rise buildings in Hong Kong. (Abstract shortened by UMI.)

Kwok, Yu Fat

292

A case study of elementary teachers' conceptions of environmental literacy in relationship to a tall grass prairie restoration project  

NASA Astrophysics Data System (ADS)

The purpose of this qualitative case study was to describe seven elementary teachers' conceptions of environmental literacy in relationship to a tall grass prairie restoration project and to explore ways in which the tall grass prairie restoration project for third grade contributed to enhancing educational learning experiences. The research questions were: 1. What are teachers' conceptions of environmental literacy for third grade students? 2. How does the prairie restoration trip contribute to teachers' capacity to teach for environmental literacy of third grade students? 3. What is the pedagogical value of the prairie restoration project? The theoretical frameworks underpinning this study were David Sobel's (1996) model for developmental progression in children's relationships with nature, and the North American Environmental Education Association's (2011) framework for environmental literacy. The first assertion derived from thematic data analysis of interviews, field trip observations, classroom observations, and artifacts was, The participating teachers' visions of environmental literacy for third grade students included components that spanned across a developmentally appropriate progression from cultivating empathy for living things, to fueling discovery of nature, to fostering a sense of responsibility toward the natural world . Components of environmental literacy described by teachers included being at ease in the natural environment, appreciation and respect, wonder and curiosity, awareness and interdependence, sense of agency, responsibility and service, and environmental knowledge. The second assertion stemming from thematic data analysis was, The prairie restoration project and related curriculum have pedagogical value that included and exceeded addressing state science standards. In addition to addressing state science standards identified by teachers, the curriculum related to the prairie restoration project served as an agent of curricular cohesion to integrate a variety of subject areas, developed scientific ways of thinking, provided life experience for children, and fostered authentic learning experiences through concrete connections. It also provided a means to enhance the presence of science and social studies in elementary curriculum. Themes emerging from qualitative data analysis resonated with Sobel's model of progressive stages in children's relationships with nature, and resulted in a tool potentially useful for design of elementary curriculum aimed at developing environmental literacy.

Shume, Teresa Jayne

293

Sinusoidal reference strategy for adaptive feedforward vibration control: numerical simulation and experimental study  

NASA Astrophysics Data System (ADS)

A new control approach named Sinusoidal Reference Strategy is developed for adaptive feedforward structural control. In this approach, the recursive-least-squares algorithm is used and a higher frequency sinusoidal signal is utilized as the reference signal. The present approach is able to overcome some of the shortcomings of the conventional adaptive feedforward control. Numerical simulations are then conducted on reducing wind-induced vibrations of the JIN MAO Building in Shanghai, China, with a height of 420 m. A multiple-degree-of-freedom (m.d.o.f.) aeroelastic model of a general super-tall building and an active mass damper (AMD) actuator are designed and manufactured. Wind tunnel tests are carried out to investigate further the control efficiency and robustness of the present approach. Both the simulation and experimental results show that the approach can reduce vibration of super-tall buildings remarkably, and can adapt to dynamic uncertainties and modelling errors of the buildings.

Peng, F. J.; Gu, M.; Niemann, H.-J.

2003-08-01

294

Poly-cyclodextrin and poly-paclitaxel nano-assembly for anticancer therapy  

NASA Astrophysics Data System (ADS)

Effective anticancer therapy can be achieved by designing a targeted drug-delivery system with high stability during circulation and efficient uptake by the target tumour cancer cells. We report here a novel nano-assembled drug-delivery system, formed by multivalent host–guest interactions between a polymer–cyclodextrin conjugate and a polymer–paclitaxel conjugate. The multivalent inclusion complexes confer high stability to the nano-assembly, which efficiently delivers paclitaxel into the targeted cancer cells via both passive and active targeting mechanisms. The ester linkages between paclitaxel and the polymer backbone permit efficient release of paclitaxel within the cell by degradation. This novel targeted nano-assembly exhibits significant antitumour activity in a mouse tumour model. The strategy established in this study also provides knowledge for the development of advanced anticancer drug delivery.

Namgung, Ran; Mi Lee, Yeong; Kim, Jihoon; Jang, Yuna; Lee, Byung-Heon; Kim, In-San; Sokkar, Pandian; Rhee, Young Min; Hoffman, Allan S.; Kim, Won Jong

2014-05-01

295

Functionalization of linen/cotton pigment prints using inorganic nano structure materials.  

PubMed

The present work opens up a novel strategy for the development of new multifunctional cellulosic pigment prints. The developed process aims at modifying the solvent-free pigment printing formulations via inclusion of certain inorganic nano materials namely silver (Ag-NPs), zinc oxide (ZnO-NPs), zirconium oxide (ZrO?-NPs) or titanium dioxide (TiO?-NPs) at 20 g/kg paste followed by screen printing and microwave fixation. The imparted functional properties together with the depth of the obtained prints are governed by the type of nano additives, type of binder and the pigment colorant. The imparted antibacterial and/or UV protection properties to the pigment prints were retained with an acceptable level (>70%) of durability even after 20 washing cycles. The presence of nano materials on the surface of the obtained pigment prints was confirmed using SEM images and EDX spectra. PMID:23911482

Ibahim, N A; Eid, B M; Abd El-Aziz, E; Abou Elmaaty, T M

2013-09-12

296

Nano-visualization of viral DNA breaching the nucleocytoplasmic barrier.  

PubMed

Nuclear pore complexes (NPCs) mediate all transport between the cytosol and the nucleus highly selectively. Their selectivity can become an insurmountable hurdle for exogenously applied therapeutic macromolecules. Many viruses naturally overcome the NPC barrier. Therefore, gene therapy often utilizes viral particles as nano-carriers for exogenous therapeutic macromolecules. Viral gene therapy, however, frequently leads to severe adverse effects. We intend to elucidate the mechanisms underlying controlled release of viral DNA at the NPC in order to design new non-viral approach for intranuclear DNA delivery. For this purpose, we developed a comprehensive experimental strategy combining nano-imaging and biochemical methods. Here, we apply Herpes simplex virus type 1 (HSV-1) as an ideal example. HSV-1 contains its long 145kbp DNA in a capsid which is merely 125nm in size. The capsid shields and targets the DNA specifically to the NPC. Only at the NPC, the capsid releases the DNA for nuclear delivery. The underlying mechanisms of this multi-step process remain unresolved. In this work we follow the fate of HSV-1 DNA in the process of transit across the NPC. Our results indicate an involvement of hydrophobicity for capsid opening. Furthermore, the DNA is presumably released as a single thread. We assume that it penetrates the NPC in this conformation. It is compacted by the host intranuclear proteins once it reaches the interior of the nucleus. Our proposed experimental strategy can be extended to other viruses. Moreover, our observations may help design potent non-viral based nano-carriers for gene therapy. PMID:24211704

Meyring-Wösten, Anna; Hafezi, Wali; Kühn, Joachim; Liashkovich, Ivan; Shahin, Victor

2014-01-10

297

Nano photo scouring and nano photo bleaching of raw cellulosic fabric using nano TiO2.  

PubMed

Photo catalytic action of nano TiO(2) for decomposing of some organic compounds is a well known phenomenon. This can be extended to the application on nano TiO(2) on the desized cotton fabric to decompose the hydrophobic impurities and coloring matters of the fabric. This can be nominating as a replacement for the conventional scouring and bleaching processes on cotton fabric producing the hydrophilic white cotton fabric. The photo activities of the nano TiO(2) on the desized cotton through decomposition of the cotton impurities compared for two different light exposures: UV rays and daylight. The desized cotton fabrics treated in the ultrasonic bath containing a colloidal aqueous solution of nano TiO(2)/citric acid (CA)/sodium hypophosphite (SHP). Incorporating CA in the treatment bath enhanced the treatment durability against washing, created a durable hydrophilic white cotton fabric even after several successive washings. Increasing the nano TiO(2) content enhanced the fabric hydrophilicity and whiteness features. Overall, the nano photo scouring and nano photo bleaching on the cotton fabric introduced and thoroughly discussed. This gains the application of nano TiO(2) on textile materials besides the other well known characteristics obtained on the textiles including self-cleaning, antibacterial and UV protection. PMID:22390850

Montazer, M; Morshedi, S

2012-05-01

298

Nano-mechanics of prostate cancer cells on nano-scaffolds  

NASA Astrophysics Data System (ADS)

We investigated the nano-mechanics of lowly metastatic (LNCaP) and highly metastatic (CL-1) prostate cancer cells cultured on nano-scaffolds by performing AFM indenting experiments. The functionalized nano-scaffolds allowed us to control the cell-to-substrate adhesion, hence the focal adhesion. We measured the elastic moduli at the center of the cell at different adhesion sizes of the nano-arrays. The obtained mechanical signature indicates that smaller focal adhesion could elicit apoptosis. This study, in general, demonstrates that nano-scaffolds could be used as a tool for adhesion assay and as a metastatic indicator.

Bastatas, Lyndon; Matthews, James; Hashem, Jood; Sennoune, Souad; Zanguillan-Martinez, Raul; Park, Soyeun

2012-03-01

299

Integrated nano-optic devices based on immersion nano-gratings made by imprint lithography and nano-trench-filling technology  

Microsoft Academic Search

Nano-optic retarders and polarizers based on dielectric and metal nano-gratings were fabricated by UV-nanoimprint lithography. Different from conventional nanostructure-based optical devices, atomic layer deposition, a highly uniform and conformal deposition process, were utilized to fill trenches of the both dielectric and metal nano-gratings. The resulted immersion nano-grating design opens a path for innovative nano-grating based optical devices and integrated optical

Jian Wang; Xuegong Deng; Paul Sciortino; Ron Varghese; Anguel Nikolov; Feng Liu; Xiaoming Liu; Lei Chen

2005-01-01

300

Estimation of abundance and distribution of two moist tall grasses in the Watarase wetland, Japan, using hyperspectral imagery  

NASA Astrophysics Data System (ADS)

The dominant grasses in a wetland are of critical concern for the wetland's ecological integrity, because these species provide the habitats for many small plants and animals. In this study, we used hyperspectral imagery to map the distributions of two dominant tall grasses ( Miscanthus sacchariflorus (Maxim.) Benth and Phragmites australis (Cav.) Trin. ex Stend) in the Watarase wetland, in central Japan. Stepwise multiple linear regression analysis was applied to the hyperspectral data to predict the shoot density and biomass of the two grasses. The independent data sets included original reflectance, band ratios, significant components identified by principal components analysis (PCA), and significant components identified by decision boundary feature extraction (DBFE). The coefficient of determination ( R2) and the root-mean-square error (RMSE) of model calibration and validation were used to evaluate the models. The significant DBFE components showed better ability at predicting shoot density of the two grasses than the other variables in the validating areas. The RMSE values were 7.40/m 2 for M. sacchariflorus and 13.09/m 2 for P. australis, which amounted to errors of around 10.0% and 12.6%, respectively, of the maximum shoot density measured during our surveys. All variables showed similar performance at predicting biomass, but the results were less accurate than those for shoot density. Considering the performance of the DBFE components for both shoot density and biomass prediction, we suggest that these are the best indicators for estimating the abundance of the two grasses.

Lu, Shan; Shimizu, Yo; Ishii, Jun; Funakoshi, Syo; Washitani, Izumi; Omasa, Kenji

301

Water and phosphorus content affect PAH dissipation in spiked soil planted with mycorrhizal alfalfa and tall fescue.  

PubMed

Polycyclic aromatic hydrocarbon (PAH) dissipation efficiency can be increased in the plant rhizosphere, but may be affected by various environmental factors. We investigated the effects of the watering regime and phosphorus concentration on PAH dissipation in the rhizosphere of mycorrhizal plants in a pot experiment. Two plant species, alfalfa (Medicago sativa) and tall fescue (Festuca arundinacea), were co-cultured and inoculated with an arbuscular mycorrhizal (AM) fungus (Glomus intraradices) in PAH (phenanthrene (PHE)=500 mg kg(-1), pyrene (PYR)=500 mg kg(-1), dibenzo(a,h)anthracene (DBA)=65 mg kg(-1)) spiked agricultural soil for 6 weeks. Treatments with different phosphorus concentrations and watering regimes were compared. The PHE dissipation reached 90% in all treatments and was not affected by the treatments. The major finding was the significant positive impact of mycorrhizal plants on the dissipation of high molecular weight PAH (DBA) in high-water low-phosphorus treatment. Such an effect was not observed in high-water high-phosphorus and low-water low-phosphorus treatments, where AM colonization was very low. A positive linear relationship was detected between PYR dissipation and the percentage of Gram-positive PAH-ring hydroxylating dioxygenase genes in high-water high-phosphorus treatments, but not in the other two treatments with lower phosphorus concentrations and water contents. Such results indicated that the phosphorus and water regime were important parameters for the dissipation of HMW-PAH. PMID:19775720

Zhou, X B; Cébron, A; Béguiristain, T; Leyval, C

2009-10-01

302

Structure of the Notch1-negative regulatory region: implications for normal activation and pathogenic signaling in T-ALL  

SciTech Connect

Proteolytic resistance of Notch prior to ligand binding depends on the structural integrity of a negative regulatory region (NRR) of the receptor that immediately precedes the transmembrane segment. The NRR includes the 3 Lin12/Notch repeats and the juxtamembrane heterodimerization domain, the region of Notch1 most frequently mutated in T-cell acute lymphoblastic leukemia lymphoma (T-ALL). Here, we report the x-ray structure of the Notch1 NRR in its autoinhibited conformation. A key feature of the Notch1 structure that maintains its closed conformation is a conserved hydrophobic plug that sterically occludes the metalloprotease cleavage site. Crystal packing interactions involving a highly conserved, exposed face on the third Lin12/Notch repeat suggest that this site may normally be engaged in intermolecular or intramolecular protein-protein interactions. The majority of known T-ALL-associated point mutations map to residues in the hydrophobic interior of the Notch1 NRR. A novel mutation (H1545P), which alters a residue at the crystal-packing interface, leads to ligand-independent increases in signaling in reporter gene assays despite only mild destabilization of the NRR, suggesting that it releases the autoinhibitory clamp on the heterodimerization domain imposed by the Lin12/Notch repeats. The Notch1 NRR structure should facilitate a search for antibodies or compounds that stabilize the autoinhibited conformation.

Gordon, Wendy R.; Roy, Monideepa; Vardar-Ulu, Didem; Garfinkel, Megan; Mansour, Marc R.; Aster, Jon C.; Blacklow, Stephen C.; (BWH); (Wellesley); (UCL)

2009-09-02

303

Characterization of the FaVRT-2 gene encoding a MADS-box transcription factor responsive to vernalization in tall fescue (Festucaarundinacea)  

Microsoft Academic Search

Delay of floral transition is a valuable trait in commercially important turfgrass species. It has been reported that short vegetative phase (SVP)-like proteins, potential repressors of the floral inductive pathway, control the transition from vegetative to reproductive phase. A homolog of SVP-like genes was isolated from tall fescue (Festuca arundinacea) by 5?-rapid amplification of cDNA ends (RACE) and 3?-RACE and

X.-L. Wang; X.-X. Liu; W. Chen; W.-C. Li; J. H. Wu; S.-Y. Wang; Y.-C. Yang; L.-Q. Xi

2012-01-01

304

Seasonal, synoptic, and diurnal-scale variability of biogeochemical trace gases and O2 from a 300-m tall tower in central Siberia  

Microsoft Academic Search

We present first results from 19 months of semicontinuous concentration measurements of biogeochemical trace gases (CO2, CO, and CH4) and O2, measured at the Zotino Tall Tower Observatory (ZOTTO) in the boreal forest of central Siberia. We estimated CO2 and O2 seasonal cycle amplitudes of 26.6 ppm and 134 per meg, respectively. An observed west-east gradient of about ?7 ppm

Elena A. Kozlova; Andrew C. Manning; Yegor Kisilyakhov; Thomas Seifert; Martin Heimann

2008-01-01

305

Effects of initial and extended exposure to an endophyte-infected tall fescue seed diet on faecal and urinary excretion of ergovaline and lysergic acid in mature geldings  

Microsoft Academic Search

AIM: To determine the amount of ergovaline and lysergic acid retained or excreted by geldings fed endophyte-infected seed containing known concentrations of these alkaloids, and the effects of exposure time on clinical expression of toxicosis.METHODS: Mature geldings (n=10) received diets containing either endophyte-free (E-) or endophyte-infected (E+) tall fescue seed during three experimental phases. The first phase (Days ?14 to

CL Schultz; SL Lodge-Ivey; LP Bush; AM Craig; JR Strickland

2006-01-01

306

DEVELOPMENT OF HPLC METHOD FOR THE DETERMINATION OF GASTRODIN AND PARA-HYDROXYBENZYL ALCOHOL IN TALL GASTRODIA TUBER ON THE POLYGLYCOL-C8 COLUMN  

Microsoft Academic Search

Compared with the C8 and C18 reversed phases the polyglycol-C8 bonded phase synthesized in this laboratory exhibits strong retention and different selectivity to hydrophilic solutes. Their characteristic advantages were used to develop a HPLC method for the analysis of the active components, gastrodin and p-hydroxybenzyl alcohol, in tall gastrodia tuber. The chromatographic conditions were optimized by means of computer-assisted method

H. Deng; C.-L. Liu; H.-X. Zhang; M.-C. Liu; P.-L. Zhu

2001-01-01

307

Determination of gastrodin, p -hydroxybenzyl alcohol, vanillyl alcohol, p -hydroxylbenzaldehyde and vanillin in tall gastrodia tuber by high-performance liquid chromatography  

Microsoft Academic Search

Summary  A high-performance liquid chromatographic method for the separation and determination of gastrodin,p-hydroxybenzyl alcohol, vanillyl alcohol,p-hydroxylbenzaldehyde and vanillin in extract of Chinese herbal medicine tall gastrodia tuber (Chinese name: Tianma) was established.\\u000a The chromatographic conditions were optimized by means of computer-assisted method development technique. Dry-Lab software\\u000a was used to model the retention behavior of the compounds as a function of gradient

C. L. Liu; M. C. Liu; P. L. Zhu

2002-01-01

308

Nano-fabricated size exclusion chromatograph  

NASA Technical Reports Server (NTRS)

This poster describes the development of a nano-fabricated size exclusion chromatograph (nSEC) based on the principle that molecules traveling through a microcolumn containing nano-fabricated features will have characteristics elution times that directly correlate to molecular weight.

Svehla, D.; Feldman, S.; Feldman, J.; Grunthaner, F.; Shakkottai, P.; dle Castillo, L.; White, V.

2002-01-01

309

New Functional Device using Bio Nano Process.  

National Technical Information Service (NTIS)

In order to fabricate new dye-sensitised solar cells, we studied a new photoresponsive electrode structure using bio-nano processes. Carbon nanotube-TiO2 hybrid materials having multitudinous nano-scale cavities were realized using a bifunctional cage-sha...

Y. Uraoka

2011-01-01

310

Ceramic bioactivity and related biomimetic strategy  

Microsoft Academic Search

Bioactivity a property displayed by ceramics such as Bioglass®, hydroxyapatite and glass-ceramic A–W is a surface property, which provides a chemical integration of synthetic materials with living tissue. A core mechanism of bioactivity is the biomineralization of calcium phosphate nano-crystals on ceramics with specific compositions and structures, inspiring acellular and protein-free biomimetic strategies for bio-interactive materials with new physical, chemical

H.-M. Kim

2003-01-01

311

Enhanced salt tolerance of transgenic progeny of tall fescue (Festuca arundinacea) expressing a vacuolar Na+/H+ antiporter gene from Arabidopsis.  

PubMed

Salinity is a major abiotic stress factor limiting crop production. To generate salt-tolerant turf and forage, we had transformed tall fescue (Festuca arundinacea) with AtNHX1, a vacuolar Na(+)/H(+) antiporter gene from Arabidopsis thaliana. In this paper, we report that overexpression of the AtNHX1 gene confers enhanced salt tolerance to the transformed tall fescue progenies. DNA gel blot analysis and reverse transcription (RT) polymerase chain reaction (PCR) were carried out to confirm the inheritance and expression of the AtNHX1 gene in transgenic T(1) and T(2) lines. These transgenic lines showed no phenotypic changes or yield reduction. Plants carrying the AtNHX1 gene were more resistant to a 20 mM NaCl solution than control plants. The roots of the transgenic lines had a higher sodium content than controls, due to an increased Na(+)/H(+) antiporter activity in tonoplast vesicles. Our results suggest that this accumulation of sodium in vacuoles of root cells, mediated by vacuolar Na(+)/H(+) antiporters, reduced the toxic effects of salinity to tall fescue and thus enhanced its salt tolerance. PMID:17561307

Zhao, Junsheng; Zhi, Daying; Xue, Zheyong; Liu, Heng; Xia, Guangmin

2007-10-01

312

c-Myc inhibition prevents leukemia initiation in mice and impairs the growth of relapsed and induction failure pediatric T-ALL cells.  

PubMed

Although prognosis has improved for children with T-cell acute lymphoblastic leukemia (T-ALL), 20% to 30% of patients undergo induction failure (IF) or relapse. Leukemia-initiating cells (LICs) are hypothesized to be resistant to chemotherapy and to mediate relapse. We and others have shown that Notch1 directly regulates c-Myc, a known regulator of quiescence in stem and progenitor populations, leading us to examine whether c-Myc inhibition results in efficient targeting of T-ALL-initiating cells. We demonstrate that c-Myc suppression by small hairpin RNA or pharmacologic approaches prevents leukemia initiation in mice by eliminating LIC activity. Consistent with its anti-LIC activity in mice, treatment with the BET bromodomain BRD4 inhibitor JQ1 reduces C-MYC expression and inhibits the growth of relapsed and IF pediatric T-ALL samples in vitro. These findings demonstrate a critical role for c-Myc in LIC maintenance and provide evidence that MYC inhibition may be an effective therapy for relapsed/IF T-ALL patients. PMID:24394663

Roderick, Justine E; Tesell, Jessica; Shultz, Leonard D; Brehm, Michael A; Greiner, Dale L; Harris, Marian H; Silverman, Lewis B; Sallan, Stephen E; Gutierrez, Alejandro; Look, A Thomas; Qi, Jun; Bradner, James E; Kelliher, Michelle A

2014-02-13

313

NanoSense: Nanoscience Activities  

NSDL National Science Digital Library

Drawing on concepts from physics, chemistry, and biology, NanoSense units reflect the interdisciplinary nature of nanoscience, emphasize fundamental nanoscience concepts such as size and scale and surface dominance of reactions, and explore applications of nanoscience and how they could affect society and policy.Each unit includes background materials and directions for the teacher, activities and instructional materials for students, and embedded assessments. Available units include:- Size Matters: Introduction to Nanoscience -- Clear Sunscreen: How Light Interacts with Matter -- Clean Energy: Converting Light into Electricity -- Fine Filters: Filtering Solutions for Clean Water.

2014-01-29

314

Vacuum nano-hole array embedded organic light emitting diodes  

NASA Astrophysics Data System (ADS)

We demonstrated a nano-hole array (NHA) embedded structure that was fabricated for organic light emitting diodes (OLEDs) using a robust reverse transfer process. The NHA structure is proposed in this study as a strategy for maximizing the diffraction strength of two dimensional photonic crystals (PCs) by engineering vacuum nano-holes inside a dielectric slab. The electroluminescence (EL) intensity of the OLED was improved by more than twice. Such an optical enhancement was evaluated by using the angular dependence of photoluminescence (PL). The FDTD simulation was carried out to optimize the NHA structure for extraction of the emission induced from both vertical and horizontal dipoles. We explored the effect of the NHA structure on the extraction improvement converted from waveguide mode by measuring EL intensities of the devices with a hemisphere lens. In addition, the transfer process employed in this study yielded extremely low surface roughness, and thus outstanding electrical characteristics.We demonstrated a nano-hole array (NHA) embedded structure that was fabricated for organic light emitting diodes (OLEDs) using a robust reverse transfer process. The NHA structure is proposed in this study as a strategy for maximizing the diffraction strength of two dimensional photonic crystals (PCs) by engineering vacuum nano-holes inside a dielectric slab. The electroluminescence (EL) intensity of the OLED was improved by more than twice. Such an optical enhancement was evaluated by using the angular dependence of photoluminescence (PL). The FDTD simulation was carried out to optimize the NHA structure for extraction of the emission induced from both vertical and horizontal dipoles. We explored the effect of the NHA structure on the extraction improvement converted from waveguide mode by measuring EL intensities of the devices with a hemisphere lens. In addition, the transfer process employed in this study yielded extremely low surface roughness, and thus outstanding electrical characteristics. Electronic supplementary information (ESI) available: The contents include details about the FDTD modeling, PL specimen fabrication, OLED device fabrication, and PL/EL measurement set-up. Further information is provided relating to the NHA substrate as well. See DOI: 10.1039/c3nr05331h

Jeon, Sohee; Jeong, Jun-Ho; Song, Young Seok; Jeong, Won-Ik; Kim, Jang-Joo; Youn, Jae Ryoun

2014-02-01

315

Endophyte-mediated resistance to black cutworm as a function of plant cultivar and endophyte strain in tall fescue.  

PubMed

To improve Neotyphodium endophyte-mediated resistance to black cutworm Agrotis ipsilon (Hufnagel) (BCW), a series of experiments was conducted by using several different cultivars of tall fescue, Schedonorus arundinaceus (Schreb.) Dumort. in combination with several different haplotypes of the endophyte Neotyphodium coenophialum (Morgan-Jones & Gams) (plant cultivar × endophyte haplotype = plant line), each producing unique alkaloid profiles. BCW settling response, survival at 5 and 10 d, and larval biomass varied significantly among plant lines. In general, greater variation BCW performance was observed within a single plant cultivar infected with different endophyte haplotypes than among different plant cultivars infected with the same endophyte haplotype, but comparisons among the former were far more numerous. Although five endophyte-mediated alkaloids representing three alkaloid classes were quantified in the plants, the pyrrolizidine alkaloid N-acetyl norloline was consistently the single best predictor of BCW performance. BCW settling response, 5-d survival, and 10-d survival decreased as levels of the alkaloid N-acetyl norloline increased. The same three response variables also decreased with increasing levels of peramine, but increased with increasing levels of ergovaline. Minor variation in endophyte infection levels occurring among infected plant lines had no significant influence on BCW performance. Results indicate a potentially important role for N-acetyl norloline and peramine in providing resistance to black cutworm whereas ergovaline appears to be much less important. Therefore, endophyte haplotypes expressing high levels of N-acetyl norloline and peramine may be of particular importance for developing 'friendly' endophyte-enhanced turf and pasture grasses that resist challenging lepidopteran pests, although remaining safe for wildlife and grazing mammals. PMID:22251642

Baldauf, Michael W; Mace, Wade J; Richmond, Douglas S

2011-06-01

316

FBN1 gene mutation defines the profibrillin to fibrillin processing site and segregates with tall stature in a family  

SciTech Connect

Dermal fibroblasts from a 13-year-old boy with skeletal features of the Marfan syndrome were used to study fibrillin synthesis and processing. Synthesis and secretion of profibrillin was normal but only half of the secreted profibrillin was converted to fibrillin, an extracellular proteolytic processing that removes a 20 kDa fragment from the protein. All the secreted profibrillin was processed to fibrillin in control cells. Only the processed form of fibrillin was deposited into the extracellular matrix in both the proband`s and the control cells. Electron microscopic examination of rotary shadowed microfibrils made by the proband`s fibroblasts were indistinguishable from control cells. Screening exons in the 3{prime} end of the FBN1 gene revealed a heterozygous C to T transition at nucleotide 5482 of the FBN1 cDNA changing R 1828 to W. This mutation disrupts a known consensus sequence recognized by a cellular protease and is located in the carboxy terminus at a site predicted to remove a 19 kD fragment. The proband and his 22-year-old brother, also heterozygous for the mutation, have had normal echocardiograms and ophthalmologic exams. The mutation segregated in the proband`s three generation family with autosomal dominant inheritance of height (> 90th percentile) and no known cardiovascular or ocular problems, including the 67-year-old grandmother (exams pending). The mutation was not found in 90 chromosomes from unrelated individuals. In summary, (1) the mutation identifies the cleavage site for the conversion of profibrillin to fibrillin; (2) the characterized mutation segregates in the family with tall stature without known cardiovascular or ocular problems; (3) this mutation potentially defines the phenotype associated with a {open_quotes}null{close_quotes} allele for the FBN1 gene.

Grossfield, J.; Cao, S.; Milewicz, D. [Univ. of Texas Medical School, Houston, TX (United States)] [and others

1994-09-01

317

Comparison of ground and satellite based measurements of the fraction of photosynthetically active radiation intercepted by tall-grass prairie  

NASA Technical Reports Server (NTRS)

The fraction of photosynthetically active radiation intercepted by vegetation, F(sub ipar) is an important parameter for modeling the interactions between the land-surface and atmosphere and for estimating vegetation biomass productivity. This study was, therefore, an integral part of FIFE. The specific purpose of this experiment was to find out how well definitive measurements of F(sub ipar) on the ground relate to near-ground and satellite based spectral reflectance measurements. Concurrent measurements of F(sub ipar) and ground, helicopter, and satellite based reflectance measurements were taken at thirteen tall-grass prairie sites within the FIFE experimental area. The sites were subjected to various combinations of burning and grazing managements. The ground and helicopter based reflectance measurements were taken on the same day or few days from the time of the overpass of LANDSAT and SPOT satellites. Ground-based reflectance measurements and sun photometer readings taken at the times of the satellite overpasses were used to correct for atmospheric attenuation. Hand-held radiometer spectral indices were strongly correlated with helicopter and satellite based values (r = 0.94 for helicopter, 0.93 for LANDSAT Thematic Mapper, and 0.86 for SPOT). However, the ground, helicopter, and satellite based normalized difference spectral vegetation indices showed low sensitivity to changes in F(sub ipar). Reflectance measurements were only moderately well correlated with measurements of F(sub ipar) (r = 0.82 for hand-held radiometer, 0.84 for helicopter measurements, and 0.75 for the LANDSAT Thematic Mapper and SPOT). Improved spectral indices which can compensate for site differences are needed in order to monitor F(sub ipar) more reliably.

Demetriades-Shah, T. H.; Kanemasu, E. T.; Flitcroft, I. D.; Su, H.

1992-01-01

318

Scale effects in gas nano flows  

NASA Astrophysics Data System (ADS)

Most previous studies on gas transport in nano-scale confinements assume dynamic similarity with rarefied gas flows, and employ kinetic theory based models. This approach is incomplete, since it neglects the van der Waals forces imposed on gas molecules by the surfaces. Using three-dimensional molecular dynamics (MD) simulations of force driven gas flows, we show the significance of wall force field in nano-scale confinements by defining a new dimensionless parameter (B) as the ratio of the wall force-penetration length to the channel height. Investigation of gas transport in different nano-channels at various Knudsen numbers show the importance of wall force field for finite B values, where the dynamic similarity between the rarefied and nano-scale gas flows break down. Comparison of MD results employing molecularly structured three-dimensional walls versus reflection of gas molecules from a two-dimensional planar surface with Maxwell distribution show that the nano-confinement effects cannot be resolved by the latter approach, frequently used in kinetic theory calculations. Molecularly structured walls determine the bulk flow physics by setting a proper tangential momentum accommodation coefficient, and they also determine the transport in the near wall region. Gas nano-flows with finite B exhibit significant differences in the local density and velocity profiles, affecting the mass flow rate and the formation of Knudsen's minimum in nano-channels.

Barisik, Murat; Beskok, Ali

2014-05-01

319

Nano-Ceramic Coated Plastics  

NASA Technical Reports Server (NTRS)

Plastic products, due to their durability, safety, and low manufacturing cost, are now rapidly replacing cookware items traditionally made of glass and ceramics. Despite this trend, some still prefer relatively expensive and more fragile ceramic/glassware because plastics can deteriorate over time after exposure to foods, which can generate odors, bad appearance, and/or color change. Nano-ceramic coatings can eliminate these drawbacks while still retaining the advantages of the plastic, since the coating only alters the surface of the plastic. The surface coating adds functionality to the plastics such as self-cleaning and disinfectant capabilities that result from a photocatalytic effect of certain ceramic systems. These ceramic coatings can also provide non-stick surfaces and higher temperature capabilities for the base plastics without resorting to ceramic or glass materials. Titanium dioxide (TiO2) and zinc oxide (ZnO) are the candidates for a nano-ceramic coating to deposit on the plastics or plastic films used in cookware and kitchenware. Both are wide-bandgap semiconductors (3.0 to 3.2 eV for TiO2 and 3.2 to 3.3 eV for ZnO), so they exhibit a photocatalytic property under ultraviolet (UV) light. This will lead to decomposition of organic compounds. Decomposed products can be easily washed off by water, so the use of detergents will be minimal. High-crystalline film with large surface area for the reaction is essential to guarantee good photocatalytic performance of these oxides. Low-temperature processing (<100 C) is also a key to generating these ceramic coatings on the plastics. One possible way of processing nanoceramic coatings at low temperatures (< 90 C) is to take advantage of in-situ precipitated nanoparticles and nanostructures grown from aqueous solution. These nanostructures can be tailored to ceramic film formation and the subsequent microstructure development. In addition, the process provides environment- friendly processing because of the aqueous solution. Low-temperature processing has also shown versatility to generate various nanostructures. The growth of low-dimensional nanostructures (0-D, 1-D) provides a means of enhancing the crystallinity of the solution-prepared films that is of importance for photocatalytic performance. This technology can generate durable, fully functional nano-ceramic coatings (TiO2, ZnO) on plastic materials (silicone, Teflon, PET, etc.) that can possess both photocatalytic oxide properties and flexible plastic properties. Processing cost is low and it does not require any expensive equipment investment. Processing can be scalable to current manufacturing infrastructure.

Cho, Junghyun

2013-01-01

320

Attostreaking with metallic nano-objects  

NASA Astrophysics Data System (ADS)

The application of atto-second streaking spectroscopy (ASS) to direct time-domain studies of the plasmonic excitations in metallic nano-objects is addressed theoretically. The streaking spectrograms for a rectangular gold nano-antenna and spherical gold clusters are obtained within strong field approximation using classical electron trajectory calculations. The results reported here for spherical clusters are also representative of spherical nano-shells. This study demonstrates that ASS allows for detailed characterization of plasmonic modes, including near-field enhancement, frequency and decay rate. The role of the inhomogeneity of the induced electric fields is also demonstrated.

Borisov, A. G.; Echenique, P. M.; Kazansky, A. K.

2012-02-01

321

NanoSpace - Virtual Amusement Park  

NSDL National Science Digital Library

NanoSpace, a free website developed by the Rensselear Polytechnic Institute, was created to increase science literacy utilizing an amusement park. NanoSpace is designed to teach science to elementary and middle school students through more than 25 games and animations that entice kids to learn more about atoms and molecules in NanoSpace. Visitors can try to beat the clock in the Periodic Memory and click-and-drag atoms to construct molecules in "Build `Em." Answer multiple-choice questions in "Who wants to be a Quidecillionaire?," and hope the answer is correct before you fall down to the bottom rung again.

Project, The M.

322

Nano-Emulsions:. Overview and Applications  

NASA Astrophysics Data System (ADS)

Nano-emulsions, also called sub-micrometer emulsions, are one of the most important nanocarriers in nanomedicine. More than 40% active susbtances are hydrophobic and therefore they are difficult to be formulated using conventional approaches. Nano-emulsion systems are considered as new vehicles for hydrophobic drug administration because they can enhance the penetration and absorption of these hydrophobic active compounds and provide safer and more patient-compliant dosage forms. This chapter describes the conception and methods of preparation of nano-emulsions, their characterization methods and their applications in pharmacetical areas.

Li, Xiang; Anton, Nicolas; Vandamme, Thierry

2013-09-01

323

Silicon periodic nano-structures obtained by laser exposure of nano-wires  

Microsoft Academic Search

Silicon nano-wires were fabricated using thin Silicon on Insulator (SOI) wafers and a combination of anisotropic wet etching by Tetra-Methyl Ammonium Hydroxide (TMAH) and Local Oxidation of Silicon (LOCOS). These nano-wires were submitted to laser exposure using gas immersion laser doping (GILD). The result was the formation of either periodic nano-structures or silicon balls. Since the process uses very short

K. Kakushima; T. Bourouina; T. Sarnet; G. Kerrien; D. Débarre; J. Boulmer; H. Fujita

2005-01-01

324

Fabrication and characterization of ABS nano composite reinforced by nano sized alumina particulates  

Microsoft Academic Search

To study the effect of addition of alumina nano sized particles in ABS thermoplastic composites, ABS was reinforced by nano\\u000a sized alumina particles through melt compounding. The microstructure, thermal stability, dynamic mechanical, static mechanical\\u000a properties and tribological analysis of the developed nano composite were investigated in detail. The dispersion morphology\\u000a of alumina particles in the ABS polymer matrix was investigated

Vivek Kumar; J. RamKumar; S. Aravindan; S. K. Malhotra; K. Vijai; Mukul Shukla

2009-01-01

325

Hot spots in highly Raman-enhancing silver nano-dendrites  

Microsoft Academic Search

A convenient strategy is demonstrated for placing C60 nanoclusters in hot spots between neighbouring arms of silver nano-dendrites leading to intense surface-enhanced Raman scattering (SERS) enhancement. The finite difference time domain calculations indicate that the dendrite-like model pattern may demonstrate a high quality SERS property owing to the 'metal\\/nanoclusters\\/metal' hot geometries. Further calculations provide useful guidelines for the synthesis of

Teng Qiu; Yongjin Zhou; Jiaqi Li; Wenjun Zhang; Xianzhong Lang; Tiejun Cui; Paul K. Chu

2009-01-01

326

NanoElectronic MOdeling (NEMO)  

NASA Astrophysics Data System (ADS)

We present a new modeling program that calculates the electronic properties of one-dimensional nanoelectronic resonant tunneling devices. The NanoElectronic MOdeling (NEMO) program uses a non-equilibrium Green function formalism to determine current, energy resonances, band energy profile, and charge density as a function of bias and temperature. Quantum charge, resonant levels, scattering, and band structure effects are taken into account. The scattering mechanisms include polar-optical phonon, acoustic phonon, alloy, and interface roughness scattering. Novel boundary conditions treat large leads with spatially varying potentials and injection into the device from quantized emitter states. Calculation results were compared to current vs voltage measurements performed on double-barrier resonant tunneling diodes with barrier-well combinations of AlGaAs-GaAs, AlAs-GaAs, and InAlAs-InGaAs. Comparisons between theory and experiment will be presented for a variety of calculation options.

Blanks, D.; Klimeck, G.; Lake, R.; Bowen, R.; Moise, T.; Jovanovic, D.; Leng, M.; Frensley, W.; Sotirelis, P.

1996-03-01

327

Surface enhanced Raman scattering of gold\\/C 60 (\\/C 70) nano-clusters deposited on AAO nano-sieve  

Microsoft Academic Search

Anodic alumina oxide (AAO) nano-sieves were prepared. Surface enhanced Raman scattering (SERS) spectra with very good quality of gold\\/C60 (\\/C70) nano-clusters deposited on the AAO nano-sieves were reported for the first time using pyridine as an intermediate to connect and nest the C60\\/C70 molecules to the gap of gold nano-particles and AAO nano-sieve. The enhancement factors are estimated to be

Luo Zhixun; Fang Yan; Zhang Pengxiang

2006-01-01

328

E-cadherin regulates human Nanos1, which interacts with p120ctn and induces tumor cell migration and invasion.  

PubMed

Down-regulation of the epithelial cell-cell adhesion molecule E-cadherin is frequently associated with tumor formation and progression. Besides its role in physical cell-cell adhesion, E-cadherin is also thought to be involved in intracellular signaling in normal epithelial cells. In these cells, the Armadillo catenin p120ctn binds to the cytoplasmic domain of E-cadherin and stabilizes the adhesion complexes. On loss of E-cadherin, cytoplasmic p120ctn might accumulate and contribute to tumor malignancy. We used suppression subtractive hybridization to search for genes regulated by E-cadherin expression. We isolated human Nanos1 as a transcript of which levels decrease on E-cadherin reexpression in a human breast cancer cell line. The hNanos1 protein bears a COOH-terminal (CCHC)(2) zinc finger domain and belongs to an evolutionarily conserved protein family sharing functions in germ cell development in both vertebrates and invertebrates. We found an inverse correlation between E-cadherin and hNanos1 expression in various cell lines and under diverse conditions. Conditional expression of hNanos1 in human colorectal DLD1 cancer cells functionally abolished cell-cell adhesion. It induced cytoplasmic translocation of p120ctn, as well as strong migratory and invasive properties. We also found that the NH(2)-terminal domain of hNanos1, which is conserved only among mammals, interacts with p120ctn. hNanos1 counteracted the stimulatory effect of p120ctn on cell protrusion formation. Together, these findings describe a new function for hNanos1 as a downstream effector of E-cadherin loss contributing to tumor progression. Targeting hNanos1 might be a promising strategy in the treatment of E-cadherin-negative tumors in particular. PMID:17047063

Strumane, Kristin; Bonnomet, Arnaud; Stove, Christophe; Vandenbroucke, Roosmarijn; Nawrocki-Raby, Beatrice; Bruyneel, Erik; Mareel, Marc; Birembaut, Philippe; Berx, Geert; van Roy, Frans

2006-10-15

329

Effect of nano-structured bioceramic surface on osteogenic differentiation of adipose derived stem cells.  

PubMed

Tissue engineering strategies to construct vascularized bone grafts potentially revolutionize the treatment of massive bone loss. The surface topography of the grafts plays critical roles on bone regeneration, while adipose derived stem cells (ASCs) are known for their capability to promote osteogenesis and angiogenesis when applied to bone defects. In the present study, the effects of hydroxyapatite (HAp) bioceramic scaffolds with nanosheet, nanorod, and micro-nano-hybrid (the hybrid of nanorod and microrod) surface topographies on attachment, proliferation and osteogenic differentiation, as well as the expression of angiogenic factors of rat ASCs were systematically investigated. The results showed that the HAp bioceramic scaffolds with the micro-/nano-topography surfaces significantly enhanced cell attachment and viability, alkaline phosphatase (ALP) activity, and mRNA expression levels of osteogenic markers and angiogenic factors of ASCs. More importantly, the biomimetic feature of the hierarchical micro-nano-hybrid surface topography showed the highest stimulatory effect. The activation in Akt signaling pathway was observed in ASCs cultured on HAp bioceramics with nanorod, and micro-nano-hybrid surface topographies. Moreover, these induction effects could be repressed by Akt signaling pathway inhibitor LY294002. Finally, the in vivo bone regeneration results of rat critical-sized calvarial defect models confirmed that the combination of the micro-nano-hybrid surface and ASCs could significantly enhance both osteogenesis and angiogenesis as compared with the control HAp bioceramic scaffold with traditional smooth surface. Our results suggest that HAp bioceramic scaffolds with micro-nano-hybrid surface can act as cell carrier for ASCs, and consequently combine with ASCs to construct vascularized tissue-engineered bone. PMID:25002263

Xia, Lunguo; Lin, Kaili; Jiang, Xinquan; Fang, Bing; Xu, Yuanjin; Liu, Jiaqiang; Zeng, Deliang; Zhang, Maolin; Zhang, Xiuli; Chang, Jiang; Zhang, Zhiyuan

2014-10-01

330

Methods and Strategies: Talk Strategies  

ERIC Educational Resources Information Center

This article discusses how to promote oral language development through science. The authors describe how they incorporate academic "talk strategies" into science lessons in a nonintrusive and meaningful manner. These talk strategies are adapted from the "Avenues" (2007) curriculum for English learners (ELs), which gives examples of cooperative…

Shea, Lauren M.; Shanahan, Therese B.

2011-01-01

331

Enabling Technologies for Nano Air Vehicles.  

National Technical Information Service (NTIS)

This project investigated several areas with the aim of improving performance and operational use of nano air vehicles (NAVs) by understanding fundamental operating principles and developing key technologies. The project developed plasma actuators for thr...

J. D. Jacob

2009-01-01

332

Advanced fabrication technologies for nano-electronics.  

National Technical Information Service (NTIS)

Three novel fabrication technologies are presented which greatly increase the tools available for the realization of nano-electronic devices. First, a sub-micron area post structure descending from a metallic airbridge allows gating of regions as small as...

J. A. Simmons M. V. Weckwerth W. E. Baca

1996-01-01

333

DNA Assembly Line for Nano-Construction  

SciTech Connect

Building on the idea of using DNA to link up nanoparticles scientists at Brookhaven National Lab have designed a molecular assembly line for high-precision nano-construction. Nanofabrication is essential for exploiting the unique properties of nanoparticl

Oleg Gang

2009-03-25

334

A Nano-Introduction to Nanotechnology  

NSDL National Science Digital Library

A very small and generic introduction to the subject of nanotechnology. What makes nanoscience special? What is the history of nano? What can nanotechnology be used for by scientist and industry? What are the ethical and enviromental challenges?

Liang, Barbara

2010-10-29

335

DNA Assembly Line for Nano-Construction  

ScienceCinema

Building on the idea of using DNA to link up nanoparticles scientists at Brookhaven National Lab have designed a molecular assembly line for high-precision nano-construction. Nanofabrication is essential for exploiting the unique properties of nanoparticl

Oleg Gang

2010-01-08

336

DNA Assembly Line for Nano-Construction  

ScienceCinema

Building on the idea of using DNA to link up nanoparticles scientists at Brookhaven National Lab have designed a molecular assembly line for high-precision nano-construction. Nanofabrication is essential for exploiting the unique properties of nanoparticl

337

Nano-Modulated Ceramic Coating Deposition System.  

National Technical Information Service (NTIS)

This report outlines the design, construction, and implementation of a Nano-modulated ceramic coating deposition system. The deposition system was designed to deposit multilayer (superlattice) coatings of two or more oxide or other non-conducting material...

W. D. Sproul A. R. Lefkow

1996-01-01

338

Injectable Nano-Network for Glucose-Mediated Insulin Delivery  

PubMed Central

Diabetes mellitus, a disorder of glucose regulation, is a global burden affecting 366 million people across the world. An artificial “closed-loop” system able to mimic pancreas activity and release insulin in response to glucose level changes has the potential to improve patient compliance and health. Herein we develop a glucose-mediated release strategy for the self-regulated delivery of insulin using an injectable and acid-degradable polymeric network. Formed by electrostatic interaction between oppositely charged dextran nanoparticles loaded with insulin and glucose-specific enzymes, the nanocomposite-based porous architecture can be dissociated and subsequently release insulin in a hyperglycemic state through the catalytic conversion of glucose into gluconic acid. In vitro insulin release can be modulated in a pulsatile profile in response to glucose concentrations. In vivo studies validated that these formulations provided improved glucose control in type 1 diabetic mice subcutaneously administered with a degradable nano-network. A single injection of the developed nano-network facilitated stabilization of the blood glucose levels in the normoglycemic state (<200 mg/dL) for up to 10 days.

Gu, Zhen; Aimetti, Alex A.; Wang, Qun; Dang, Tram T.; Zhang, Yunlong; Veiseh, Omid; Cheng, Hao; Langer, Robert S.; Anderson, Daniel G.

2014-01-01

339

Lipid bilayers on nano-templates  

DOEpatents

A lipid bilayer on a nano-template comprising a nanotube or nanowire and a lipid bilayer around the nanotube or nanowire. One embodiment provides a method of fabricating a lipid bilayer on a nano-template comprising the steps of providing a nanotube or nanowire and forming a lipid bilayer around the polymer cushion. One embodiment provides a protein pore in the lipid bilayer. In one embodiment the protein pore is sensitive to specific agents

Noy, Aleksandr (Belmont, CA); Artyukhin, Alexander B. (Menlo Park, CA); Bakajin, Olgica (San Leandro, CA); Stoeve, Pieter (Davis, CA)

2009-08-04

340

Nano-Sized Carriers for Drug Delivery  

Microsoft Academic Search

Drug delivery is an important issue, especially with a new generation of therapeutics, which are either unstable in the biological\\u000a environment, have poor transport properties across biological membranes, are insoluble in water, or have very low bioavailability.\\u000a Nano-sized drug carriers can address some of the above issues and enhance their therapeutic efficacy. Different types of nano-sized\\u000a carriers, such as nanoparticles,

Sanjeeb K. Sahoo; Tapan K. Jain; Maram K. Reddy; Vinod Labhasetwar

341

Nano-fabricated size exclusion chromatograph  

NASA Technical Reports Server (NTRS)

This paper describes the development of a nano-fabricated size exclusion chromatograph (nSEC) based on the principle that molecules traveling through amicrocolumn containing nano-fabricated features will have characteristic elution times that directly correlate to molecular weight. Compared to conventional size exclusion chromatography, the nSEC offers greater control over the size exclusion process; mass fabrication; integration of the separation column with associated valves, pumps, and detectors; and dramatic reductions in instrument mass and power requirements.

Svehla, D.; Feldman, S.; Feldman, J.; Grunthaner, F.; Shakkottai, P.; Castillo, L. del; White, V.

2002-01-01

342

The tribology of nano-crystalline diamond  

Microsoft Academic Search

Nano-crystalline diamond is the hardest diamond-like carbon (DLC) with properties very close to true diamond. Among such properties is the low frictional coefficient and high wear resistance. Cemented WC disks were coated by nano-crystalline diamond deposited by cathodic arc. These disks were rubbed cyclically by pins made of aluminum–silicon alloy (4032), carbon steel (52100), and alumina ceramics (Al2O3). It was

Shenq Y. Luo; Jui-Kang Kuo; Brian Yeh; James C. Sung; Chuang-Wen Dai; Tsung J. Tsai

2001-01-01

343

How Tall Are We?  

NSDL National Science Digital Library

Kindergartners measure each others' heights using large building blocks, then visit a second- and a fourth-grade class to measure those students' heights. They also measure adults in the school community. Students display the collected data in bar graphs made from paper cut-outs of miniature building blocks glued on paper, comparing the different age groups. The associated activity for this lesson helps students develop the concepts and vocabulary to describe, in a non-ambiguous way, how height changes as children age. The introduction to graphing provides an important foundation for both creating and interpreting graphs in future years.

Engineering K-Phd Program

344

Cetacean Strategies.  

ERIC Educational Resources Information Center

Suggested are activities about whales for children in schools not near the ocean. Activities designed to pique students' interest in whales and to investigate the size, breathing, buoyancy, and feeding strategies of whales are discussed. (CW)

Gilliland, Denise DelGrosso

1991-01-01

345

The Tall Wind project - exploring the wind profile and boundary-layer height in the atmosphere's first kilometer over flat terrain.  

NASA Astrophysics Data System (ADS)

Predicting the wind at typical heights of present and future wind turbines is a considerable scientific challenge. Presently applied models are accurate within the surface layer. New measurements and instrument synergies are necessary as basis for developing new wind models and understanding the physical processes that form the wind profile in order to describe the wind profile above it. Analysis of the wind and turbulence profiles from a meteorological mast at heights up to 160 meters and wind lidars up to 300 meters at the National test station at Høvsøre, Denmark, shows deviations of the wind profile above 80 meters the from the profile used so far near the surface. It also reveals the importance of the boundary-layer height as a physical parameter for the description of the wind profile. In the Tall Wind project, mast and lidar measurements of wind and fluxes will be combined with monitoring of the boundary-layer height by use of an aerosol lidar. At the main project monitoring sites (Høvsøre in Denmark and Hamburg in Germany) long term monitoring programmes on tall masts (160 and 300 meters) already exists and will be intensified. As part of the project the wind profile will be measured up to 1000 meters by a wind lidar (windcube) and the boundary-layer height by an aerosol lidar. The new data sets can be used for theoretical developments and evaluation of meso-scale meteorological models. The project is an international collaboration between academia (Risoe-DTU, HU and KIT) and industry (Vestas and DONG), funded by the Danish Research Agency, the Strategic Research Council (Sagsnr. 2104-08-0025). In the paper the set-up of the Tall Wind project will be described and some first results and experience will be presented.

Gryning, S. E.; Batchvarova, E.; Pena, A.; Mikkelsen, T.; Brümmer, B.; Emeis, S.; Gulstad, L.; Lee, N.

2010-09-01

346

Flow and leakage characteristics of a sashless inclined air-curtain (sIAC) fume hood containing tall pollutant-generation tanks.  

PubMed

In many fume hood applications, pollutant-generation devices are tall. Human operators of a fume hood must stand close to the front of the hood and lift up their hands to reach the top opening of the tall tank. In this situation, it is inconvenient to access the conventional hood because the sash acts as a barrier. Also, the bluff-body wake in front of the operator's chest causes a problem. By using laser-assisted smoke flow visualization and tracer-gas test methods, the present study examines a sashless inclined air-curtain (sIAC) fume hood for tall pollutant-generation tanks, with a mannequin standing in front of the hood face. The configuration of the sIAC fume hood, which had the important element of a backward-inclined push-pull air curtain, was different from conventional configurations. Depending on suction velocity, the backward-inclined air curtain had three characteristic modes: straight, concave, and attachment. A large recirculation bubble covering the area--from the hood ceiling to the work surface--was formed behind the inclined air curtain in the straight and concave modes. In the attachment mode, the inclined air curtain was attached to the rear wall of the hood, about 50 cm from the hood ceiling, and bifurcated into up and down streams. Releasing the pollutants at an altitude above where the inclined air curtain was attached caused the suction slot to directly draw up the pollutants. Releasing pollutants in the rear recirculation bubble created a risk of pollutants' leaking from the hood face. The tracer-gas (SF6) test results showed that operating the sIAC hood in the attachment mode, with the pollutants being released high above the critical altitude, could guarantee almost no leakage, even though a mannequin was standing in front of the sashless hood face. PMID:24195536

Chen, Jia-Kun; Huang, Rong Fung; Hung, Wei-Lun

2013-01-01

347

Change in hydraulic properties and leaf traits of a tall rainforest tree species subjected to long-term throughfall exclusion in the perhumid tropics  

NASA Astrophysics Data System (ADS)

In a throughfall displacement experiment on Sulawesi, Indonesia, three 0.16 ha stands of a premontane perhumid rainforest were exposed to a two-year soil desiccation period that reduced the soil moisture in the upper soil layers beyond the conventional wilting point. About 25 variables, including leaf morphological and chemical traits, stem diameter growth and hydraulic properties of the xylem in the trunk and terminal twigs, were investigated in trees of the tall-growing tree species Castanopsis acuminatissima (Fagaceae) by comparing desiccated roof plots with nearby control plots. We tested the hypotheses that this tall and productive species is particularly sensitive to drought, and the exposed upper sun canopy is more affected than the shade canopy. Hydraulic conductivity in the xylem of terminal twigs normalised to vessel lumen area was reduced by 25%, leaf area-specific conductivity by 10-33% during the desiccation treatment. Surprisingly, the leaves present at the end of the drought treatment were significantly larger, but not smaller in the roof plots, though reduced in number (about 30% less leaves per unit of twig sapwood area), which points to a drought effect on the leaf bud formation while the remaining leaves may have profited from a surplus of water. Mean vessel diameter and axial conductivity in the outermost xylem of the trunk were significantly reduced and wood density increased, while annual stem diameter increment decreased by 26%. In contradiction to our hypotheses, (i) we found no signs of major damage to the C. acuminatissima trees nor to any other drought sensitivity of tall trees, and (ii) the exposed upper canopy was not more drought susceptible than the shade canopy.

Schuldt, B.; Leuschner, C.; Horna, V.; Moser, G.; Köhler, M.; Barus, H.

2010-11-01

348

Direct growth of graphene nanomesh using a Au nano-network as a metal catalyst via chemical vapor deposition  

NASA Astrophysics Data System (ADS)

Herein, we report a simple and facile method on the direct formation of graphene nanomesh (GNM) on insulating substrates by chemical vapor deposition using the Au metal nano-network as a metal catalyst. Well-ordered hexagonal honeycomb shapes of Au nano-network films synthesized using an anodized aluminum oxide template, served as catalysts for the growth of GNM. As-prepared GNM was characterized by various techniques and fabricated as a conducting channel in field effect transistors. Enhanced mobility and a relatively high ON/OFF ratio confirmed our synthetic strategy of the fabrication of GNM as an alternative to a conventional top-down lithographic approach.

Jung, Insub; Young Jang, Ho; Park, Sungho

2013-07-01

349

Self-assembly of hybrid structures on nano templates  

NASA Astrophysics Data System (ADS)

This dissertation describes the investigation on the synthesis of hybrid structures on nano-templates. Fabrication of molecular nano-patterns of organic amphiphiles (e.g. fatty acids) by self-assembly has been discussed here, and their application as templates for two-dimensional in situ synthesis of metal soap molecular pattern has been demonstrated. The synthesis of nanoparticle---nanorod hybrid structure represents another effort to achieve hybrid materials. Therefore, methods to create complex inorganic---organic nano---hybrid are provided by this work. AFM disclosed the pattern structures of the self-assembled monolayers as designed nanoscaled patterns. It is observed two pattern periodicities reflecting the head-to-head and head-to-tail molecular assembly tendencies of the fatty acids and their dependence on the molecular structure and chain length, which exhibits a linear increase in the periodicity with an increasing molecular chain length. The investigation on molecular patterns of self-assembled monolayers of metal arachidates on graphite by AFM and FTIR is described. Metal arachidate self-assemblies show similar stripe pattern and periodicities as those of arachidic acid. The monolayer structure is mainly dictated by graphite, while the type of metal ions mainly affects the domain size, shape and regularity. The results of AFM and FTIR are correlated to the Irving-Williams Series, which predicts bond strength of the metal ions to ligands. The spin coated films from binary solutions of nanoparticles and fatty acids with different chain lengths (Even number of carbon, C18--C26), have been used to study the effect of nanoparticles on self-assemble pattern of fatty acids. C18--C22 acids formed uniform nanorods attached and induced by nanoparticles, while the self-assembled stripe patterns of C24 and C26 were unaffected by the presence of nanoparticles. The nanoparticles were aligned on C26 monolayer. The seeded nucleation mechanism has been studied by AFM, TEM, UV-Vis and in situ EDS and it is disclosed the confinement effect of nanoparticles and the competition between template effects from nanoparticle and from graphite. This strategy is proven to be universal, and nano-hybrids have been fabricated using different nanoparticle seeds, fatty acids, and solvents.

Wang, Ruomiao

350

In situ phytoremediation of PAH-contaminated soil by intercropping alfalfa ( Medicago sativa L.) with tall fescue ( Festuca arundinacea Schreb.) and associated soil microbial activity  

Microsoft Academic Search

Purpose  A 7-month field experiment was conducted to investigate the polycyclic aromatic hydrocarbon (PAH) remediation potential of\\u000a two plant species and changes in counts of soil PAH-degrading bacteria and microbial activity.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods  Alfalfa and tall fescue were grown in monoculture and intercropped for 7 months in contaminated field soil. Soil and plant\\u000a samples were analyzed for PAHs. Plant biomass, densities of

Mingming Sun; Dengqiang Fu; Ying Teng; Yuanyuan Shen; Yongming Luo; Zhengao Li; Peter Christie

351

A mouse model for inducible overexpression of Prdm14 results in rapid-onset and highly penetrant T-cell acute lymphoblastic leukemia (T-ALL)  

PubMed Central

SUMMARY PRDM14 functions in embryonic stem cell (ESC) maintenance to promote the expression of pluripotency-associated genes while suppressing differentiation genes. Expression of PRDM14 is tightly regulated and typically limited to ESCs and primordial germ cells; however, aberrant expression is associated with tumor initiation in a wide variety of human cancers, including breast cancer and leukemia. Here, we describe the generation of a Cre-recombinase-inducible mouse model for the spatial and temporal control of Prdm14 misexpression [ROSA26 floxed-stop Prdm14 (R26PR)]. When R26PR is mated to either of two Cre lines, Mx1-cre or MMTV-cre, mice develop early-onset T-cell acute lymphoblastic leukemia (T-ALL) with median overall survival of 41 and 64 days for R26PR;Mx1-cre and R26PR;MMTV-cre, respectively. T-ALL is characterized by the accumulation of immature single-positive CD8 cells and their widespread infiltration. Leukemia is preceded by a dramatic expansion of cells resembling hematopoietic stem cells and lymphoid-committed progenitors prior to disease onset, accompanied by a blockage in B-cell differentiation at the early pro-B stage. Rapid-onset PRDM14-induced T-ALL requires factors that are present in stem and progenitor cells: R26PR;dLck-cre animals, which express Prdm14 starting at the double-positive stage of thymocyte development, do not develop disease. PRDM14-induced leukemic cells contain high levels of activated NOTCH1 and downstream NOTCH1 targets, including MYC and HES1, and are sensitive to pharmacological inhibition of NOTCH1 with the ?-secretase inhibitor DAPT. Greater than 50% of human T-ALLs harbor activating mutations in NOTCH1; thus, our model carries clinically relevant molecular aberrations. The penetrance, short latency and involvement of the NOTCH1 pathway will make this hematopoietic R26PR mouse model ideal for future studies on disease initiation, relapse and novel therapeutic drug combinations. Furthermore, breeding R26PR to additional Cre lines will allow for the continued development of novel cancer models.

Carofino, Brandi L.; Ayanga, Bernard; Justice, Monica J.

2013-01-01

352

Nano Surface Generation in Grinding Process using Carbon Nano Tube with Lubricant Mixture  

Microsoft Academic Search

Carbon nano tubes have been of great interest, both from a fundamental point of view and for future application. The most eye catching features of these structures are their mechanical, optical and chemical characteristics, which open a way to future application. For commercial applications large quantities of purified nanotubes are needed. Carbon nano tubes of different types can be produced

S. Prabhu; B. K. Vinayagam

353

Hybrid Nano-Imprinting Lithography Method for Nano-Patterning Based on Infrared Pulsed Laser Heating.  

National Technical Information Service (NTIS)

In this research project we present a novel method of nano- imprinting which adopts important features of conventional nano-imprinting lithography (NIL) and the newly developed laser-assisted direct imprinting (LADI) method. It utilizes an Nd-YAG pulsed l...

Y. Lee

2006-01-01

354

Nano-vectors for the Ocular Delivery of Nucleic Acid-based Therapeutics.  

PubMed

Nucleic acid-based therapeutics have gained a lot of interest for the treatment of diverse ophthalmic pathologies. The first to enter in clinic has been an oligonucleotide, Vitravene(®) for the treatment of cytomegalovirus infection. More recently, research on aptamers for the treatment of age related macular degeneration has led to the development of Macugen(®). Despite intense potential, effective ocular delivery of nucleic acids is a major challenge since therapeutic targets for nucleic acid-based drugs are mainly located in the posterior eye segment, requiring repeated invasive administration. Of late, nanotechnology-based nano-vectors have been developed in order to overcome the drawbacks of viral and other non-viral vectors. The diversity of nano-vectors allows for ease of use, flexibility in application, low-cost of production, higher transfection efficiency and enhanced genomic safety. Using nano-vector strategies, nucleic acids can be delivered either encapsulated or complexed with cationic lipids, polymers or peptides forming sustained release systems, which can be tailored according to the ocular tissue being targeted. The present review focuses on developments and advances in various nano-vectors for the ocular delivery of nucleic acid-based therapeutics, the barriers that such delivery systems face and methods to overcome them. PMID:21969738

Khar, R K; Jain, G K; Warsi, M H; Mallick, N; Akhter, S; Pathan, S A; Ahmad, F J

2010-11-01

355

The hydrogel template method for fabrication of homogeneous nano/microparticles.  

PubMed

Nano/microparticles have been used widely in drug delivery applications. The majority of the particles are prepared by the conventional emulsion methods, which tend to result in particles with heterogeneous size distribution with sub-optimal drug loading and release properties. Recently, microfabrication methods have been used to make nano/microparticles with a monodisperse size distribution. The existing methods utilize solid templates for making particles, and the collection of individual particles after preparation has not been easy. The new hydrogel template approach was developed to make the particle preparation process simple and fast. The hydrogel template approach is based on the unique properties of physical gels that can undergo sol-gel phase transition upon changes in environmental conditions. The phase reversible hydrogels, however, are in general mechanically too weak to be treated as a solid material. It was unexpectedly found that gelatin hydrogels could be made to possess various properties necessary for microfabrication of nano/microparticles in large quantities. The size of the particles can be adjusted from 200 nm to >50 microm, providing flexibility in controlling the size in drug delivery formulations. The simplicity in processing makes the hydrogel template method useful for scale-up manufacturing of particles. The drug loading capacity is 50% or higher, and yet the initial burst release is minimal. The hydrogel template approach presents a new strategy of preparing nano/microparticles of predefined size and shape with homogeneous size distribution for drug delivery applications. PMID:19822178

Acharya, Ghanashyam; Shin, Crystal S; McDermott, Matthew; Mishra, Himanshu; Park, Haesun; Kwon, Ick Chan; Park, Kinam

2010-02-15

356

Nano-vectors for the Ocular Delivery of Nucleic Acid-based Therapeutics  

PubMed Central

Nucleic acid-based therapeutics have gained a lot of interest for the treatment of diverse ophthalmic pathologies. The first to enter in clinic has been an oligonucleotide, Vitravene® for the treatment of cytomegalovirus infection. More recently, research on aptamers for the treatment of age related macular degeneration has led to the development of Macugen®. Despite intense potential, effective ocular delivery of nucleic acids is a major challenge since therapeutic targets for nucleic acid-based drugs are mainly located in the posterior eye segment, requiring repeated invasive administration. Of late, nanotechnology-based nano-vectors have been developed in order to overcome the drawbacks of viral and other non-viral vectors. The diversity of nano-vectors allows for ease of use, flexibility in application, low-cost of production, higher transfection efficiency and enhanced genomic safety. Using nano-vector strategies, nucleic acids can be delivered either encapsulated or complexed with cationic lipids, polymers or peptides forming sustained release systems, which can be tailored according to the ocular tissue being targeted. The present review focuses on developments and advances in various nano-vectors for the ocular delivery of nucleic acid-based therapeutics, the barriers that such delivery systems face and methods to overcome them.

Khar, R. K.; Jain, G. K.; Warsi, M. H.; Mallick, N.; Akhter, S; Pathan, S. A.; Ahmad, F. J.

2010-01-01

357

Variation and Defect Tolerance for Nano Crossbars  

NASA Astrophysics Data System (ADS)

With the extreme shrinking in CMOS technology, quantum effects and manufacturing issues are getting more crucial. Hence, additional shrinking in CMOS feature size seems becoming more challenging, difficult, and costly. On the other hand, emerging nanotechnology has attracted many researchers since additional scaling down has been demonstrated by manufacturing nanowires, Carbon nanotubes as well as molecular switches using bottom-up manufacturing techniques. In addition to the progress in manufacturing, developments in architecture show that emerging nanoelectronic devices will be promising for the future system designs. Using nano crossbars, which are composed of two sets of perpendicular nanowires with programmable intersections, it is possible to implement logic functions. In addition, nano crossbars present some important features as regularity, reprogrammability, and interchangeability. Combining these features, researchers have presented different effective architectures. Although bottom-up nanofabrication can greatly reduce manufacturing costs, due to low controllability in the manufacturing process, some critical issues occur. Bottom- up nanofabrication process results in high variation compared to conventional top- down lithography used in CMOS technology. In addition, an increased failure rate is expected. Variation and defect tolerance methods used for conventional CMOS technology seem inadequate for adapting to emerging nano technology because the variation and the defect rate for emerging nano technology is much more than current CMOS technology. Therefore, variations and defect tolerance methods for emerging nano technology are necessary for a successful transition. In this work, in order to tolerate variations for crossbars, we introduce a framework that is established based on reprogrammability and interchangeability features of nano crossbars. This framework is shown to be applicable for both FET-based and diode-based nano crossbars. We present a characterization testing method which requires minimal number of test vectors. We formulate the variation optimization problem using Simulated Annealing with different optimization goals. Furthermore, we extend the framework for defect tolerance. Experimental results and comparison of proposed framework with exhaustive methods confirm its effectiveness for both variation and defect tolerance.

Tunc, Cihan

358

Nano-zirconium oxide and nano-silver oxide\\/cotton gauze fabrics for antimicrobial and wound healing acceleration  

Microsoft Academic Search

Nano-zirconium-oxide (nano-Zr-oxide) and nano-silver-oxide (nano-Ag-oxide) were in situ synthesized and deposited into cotton gauze fabrics by reduction of zirconium oxychloride or silver nitrate solutions, in the presence of fabric samples using sodium hydroxide-hydrogen peroxide mixture solution at pH 9.5. The resulted homogenous distribution of nano-Zr-oxide and nano-Ag-oxide inside the fabric were characterized by scanning electron microscopy coupled with energy dispersive

Mohamed Gouda

2012-01-01

359

Dielectric properties of nano Si\\/C\\/N composite powder and nano SiC powder at high frequencies  

Microsoft Academic Search

The dielectric properties of nano Si\\/C\\/N composite powder and nano SiC powder at high frequencies have been studied. The nano Si\\/C\\/N composite powder and nano SiC powder were synthesized from hexamethyldisilazane ((Me3Si)2NH) (Me:CH3) and SiH4–C2H2, respectively, by a laser-induced gas-phase reaction. The complex permittivities of the nano Si\\/C\\/N composite powder and nano SiC powder were measured at a frequency range

Donglin Zhao; Hongsheng Zhao; Wancheng Zhou

2001-01-01

360

Novel use of an exchange catheter to facilitate intubation with an Aintree catheter in a tall patient with a predicted difficult airway: a case report  

PubMed Central

Introduction The Aintree intubating catheter (Cook® Medical Inc., Bloomington, IN, USA) has been shown to successfully facilitate difficult intubations when other methods have failed. The Aintree intubating catheter (Cook® Medical Inc., Bloomington, IN, USA) has a fixed length of 56 cm, and it has been suggested in the literature that it may be too short for safe use in patients who are tall. Case presentation We present the case of a 32-year-old, 180 cm tall Caucasian woman with a predicted difficult airway who presented to our facility for an emergency cesarean section. After several failed intubation attempts via direct laryngoscopy, an airway was established with a laryngeal mask airway. After delivery of a healthy baby, our patient's condition necessitated tracheal intubation. A fiber-optic bronchoscope loaded with an Aintree intubating catheter (Cook® Medical Inc., Bloomington, IN, USA) was passed through the laryngeal mask airway into the trachea until just above the carina, but was too short to safely allow for the passage of an endotracheal tube. Conclusions We present a novel technique in which the Aintree intubating catheter (Cook® Medical Inc., Bloomington, IN, USA) was replaced with a longer (100 cm) exchange catheter, over which an endotracheal tube was passed successfully into the trachea.

2012-01-01

361

The Petrography of Meteoritic Nano-Diamonds  

NASA Technical Reports Server (NTRS)

At least some meteoritic nanodiamonds are likely of presolar origin because of their association with anomalous Xe-HL and Te isotopic components indicative of a supernova (SN) origin. But the abundance of Xe is such that only approx. 1 in 10(exp 6) nano-diamonds contains a Xe atom, and the bulk C-13/C-12 composition of nano-diamond acid residues is chondritic (solar). Therefore, it is possible that a significant fraction of meteoritic nano-diamonds formed within the solar nebula. Nano-diamonds have recently been detected for the first time within the accretion discs of young stars by the Infrared Space Observatory (ISO). No comparable evidence of nanodiamonds in the interstellar medium has yet been found. We have identified nano-diamonds in acid etched thin-sections of meteorites, polar micrometeorites, and interplanetary dust particles (IDPs) with the goal of determining their distribution as a function of heliocentric distance. (It is assumed the meteorites and the polar micrometeorites are from asteroids at 2-4 AU and at least some of the IDPs are from comets at >50AU). We found that nano-diamonds are heterogeneously distributed throughout carbon-rich meteoritic materials (we identified them in some IDPs and not in others), and that their abundance may actually decrease with heliocentric distance, consistent with the hypothesis that some of them formed within the inner solar system and not in a presolar (SN) environment. In order to gain further insight about the origins of meteoritic nano-diamonds we are currently investigating their distribution in unetched thin-sections. We have examined a chondritic cluster IDP (U220GCA), fragments of the Tagish Lake (CM1) meteorite, and a SN graphite spherule (KE3d8) isolated from the Murchison (CM) meteorite. We selected U220GCA because its nano-diamond abundance (in acid etched thin-sections) appears to be as much as approx. 10X higher than in Murchison matrix, Tagish Lake because it has a higher reported nano-diamond abundance than other carbonaceous chondrites (approx. 3650-4330 ppm), and KE3d8 because it is a carbon spherule with an isotopic composition suggesting that it is a bone fide presolar SN grain.

Dai, Z. R.; Bradley, J. P.; Brownlee, D. E.; Joswiak, D. J.

2003-01-01

362

Effect of enhanced nitrogen input on release of nutrients and nutrient availability in stands of tall fern Athyrium distentifolium  

NASA Astrophysics Data System (ADS)

Improved light conditions, after destruction of tree canopy, soil acidification and increased nitrogen availability, support intensive spreading of acidophilous perennial grasses and stands of tall fern (Athyrium distentifolium) on deforested sites in the Moravian-Silesian Beskydy Mts. (the Czech Republic). The aim of the study was to determine how higher inputs of nitrogen affect the release of nutrients during decomposition processes of fern litter. The experimental site was chosen on a southwest-facing slope of the Kn?hyn? Mt. (49o31´ N, 18o 32´E, 1170 m a.s.l.) in the Moravian-Silesin Beskydy Mts. in the Czech Republic. The area is characterized by an annual mean air temperature of 5.6 oC and annual precipitation of 1110 mm. A large fern stand was divided in four blocks (5x3 m) and on two of them higher doses of nitrogen were applied (50 kgN/ha in five doses in the course of the growing season). Similarly, mesh-bags with fresh natural litter of fern were used to determine rate of litter decomposition during one year. Samples were inserted in both nitrogen treated and untreated fern stands in autumn 2006 and 2007 collected in autumn 2007 and 2008. On the basis of litter amount estimated at the start and at the end of exposure and of actual content of minerals in original and exposed litter, the release and/or accumulation of minerals during decomposition were calculated. The availability (more or less in the case of ammonia-nitrogen) and movement of percolated nitrogen (mainly in the case of nitrate-nitrogen) was estimated in situ by the trapping of mineral N into the ion exchange resin (IER) inserted into special cover. The decomposition rate of native A. distentifolium litter was approximately the same (29-30 %) at both nitrogen availability, however the element release from decomposed litter was higher for N, P and Ca in both years and for K and Mg in the first year as well. However, decomposition rate of cellulose was two times greater in fern stands than in adjacent spruce stands without ferns. The values are expressed as the captured mineral nitrogen into ion exchange resins exposed in situ. The availability of soil ammonia- as well as nitrate- nitrogen in control stockings, and after the addition of different sources (raw silk and cellulose) were, in general, not very different below fern plants and in the bare soils. It can be concluded, that the microbial competition for available nitrogen is very high after the addition of cellulose, which consequently restrict the rate of mineral nitrogen trapped into the ion exchange resin. In contrary higher amounts of captured mineral nitrogen were estimated after the addition of raw silk. This study was supported by GP AS CR (IAA 600050616) and the Research plan No. MSM6215648905, Ministry of Education, CR.

Tå¯Ma, Ivan; Holuib, Petr; Záhora, Jaroslav; Fiala, Karel

2010-05-01

363

Nano-graphene in biomedicine: theranostic applications.  

PubMed

Owing to their unique physical and chemical properties, graphene and its derivatives such as graphene oxide (GO), reduced graphene oxide (RGO) and GO-nanocomposites have attracted tremendous interest in many different fields including biomedicine in recent years. With every atom exposed on its surface, single-layered graphene shows ultra-high surface area available for efficient molecular loading and bioconjugation, and has been widely explored as novel nano-carriers for drug and gene delivery. Utilizing the intrinsic near-infrared (NIR) optical absorbance, in vivo graphene-based photothermal therapy has been realized, achieving excellent anti-tumor therapeutic efficacy in animal experiments. A variety of inorganic nanoparticles can be grown on the surface of nano-graphene, obtaining functional graphene-based nanocomposites with interesting optical and magnetic properties useful for multi-modal imaging and imaging-guided cancer therapy. Moreover, significant efforts have also been devoted to study the behaviors and toxicology of functionalized nano-graphene in animals. It has been uncovered that both surface chemistry and sizes play key roles in controlling the biodistribution, excretion, and toxicity of nano-graphene. Biocompatibly coated nano-graphene with ultra-small sizes can be cleared out from body after systemic administration, without rendering noticeable toxicity to the treated mice. In this review article, we will summarize the latest progress in this rapidly growing field, and discuss future prospects and challenges of using graphene-based materials for theranostic applications. PMID:23059655

Yang, Kai; Feng, Liangzhu; Shi, Xiaoze; Liu, Zhuang

2013-01-21

364

Rotation motion of designed nano-turbine.  

PubMed

Construction of nano-devices that can generate controllable unidirectional rotation is an important part of nanotechnology. Here, we design a nano-turbine composed of carbon nanotube and graphene nanoblades, which can be driven by fluid flow. Rotation motion of nano-turbine is quantitatively studied by molecular dynamics simulations on this model system. A robust linear relationship is achieved with this nano-turbine between its rotation rate and the fluid flow velocity spanning two orders of magnitude, and this linear relationship remains intact at various temperatures. More interestingly, a striking difference from its macroscopic counterpart is identified: the rotation rate is much smaller (by a factor of ~15) than that of the macroscopic turbine with the same driving flow. This discrepancy is shown to be related to the disruption of water flow at nanoscale, together with the water slippage at graphene surface and the so-called "dragging effect". Moreover, counterintuitively, the ratio of "effective" driving flow velocity increases as the flow velocity increases, suggesting that the linear dependence on the flow velocity can be more complicated in nature. These findings may serve as a foundation for the further development of rotary nano-devices and should also be helpful for a better understanding of the biological molecular motors. PMID:25068725

Li, Jingyuan; Wang, Xiaofeng; Zhao, Lina; Gao, Xingfa; Zhao, Yuliang; Zhou, Ruhong

2014-01-01

365

Fabrication of three-dimensional nano, micro and micro/nano scaffolds of porous poly(lactic acid) by electrospinning and comparison of cell infiltration by Z-stacking/three-dimensional projection technique.  

PubMed

The use of electrospun extracellular matrix (ECM)-mimicking nanofibrous scaffolds for tissue engineering is limited by poor cellular infiltration. The authors hypothesised that cell penetration could be enhanced in scaffolds by using a hierarchical structure where nano fibres are combined with micron-scale fibres while preserving the overall scaffold architecture. To assess this, we fabricated electrospun porous poly(lactic acid) (PLA) scaffolds having nanoscale, microscale and combined micro/nano architecture and evaluated the structural characteristics and biological response in detail. Although the bioactivity was intermediate to that for nanofibre and microfibre scaffold, a unique result of this study was that the micro/nano combined fibrous scaffold showed improved cell infiltration and distribution than the nanofibrous scaffold. Although the cells were found to be lining the scaffold periphery in the case of nanofibrous scaffold, micro/nano scaffolds had cells dispersed throughout the scaffold. Further, as expected, the addition of nanoparticles of hydroxyapatite (nHAp) improved the bioactivity, although it did not play a significant role in cell penetration. Thus, this strategy of creating a three-dimensional (3D) micro/nano architecture that would increase the porosity of the fibrous scaffold and thereby improving the cell penetration, can be utilised for the generation of functional tissue engineered constructs in vitro. PMID:22423866

Shalumon, K T; Chennazhi, K P; Tamura, H; Kawahara, K; Nair, S V; Jayakumar, R

2012-03-01

366

[Immobilization of anti-transferrin on nano-gold and its immune recognition of transferrin].  

PubMed

A novel strategy based on antigen-antibody interaction was developed by means of backfilling transferrin on antibody functionalized gold nanoparticles surfaces in the present study. Nano gold particles were immobilized with cysteamine layer by self-assembly, whose surfaces were chemically coupled with anti-transferrin antibodies by using EDCX, forming the anti-transferrin-Au immuno-probes. The particles and the nano-probes were characterized by the integrated tools of resonance Rayleigh scattering (RRS), UV-Vis absorption spectra, transmission electron microscopy (TEM) and laser light scattering. The result showed that the nano-probe with the ability of specific recognition of transferrin had good immune activity. The RRS peak at 470 nm was amplified obviously by using this signal amplification, and the antigen recognition was monitored via the enhancement of 470 nm RRS intensity when this binding event occurred. The result showed that the amplification strategy led to a dramatic improvement of the detection sensitivity of transferrin, and the detection of transferrin featured a linear range of 0.85 to 33.9) x 10(-10) mol x L(-1) with the detection limit of 8.5 x 10(-11) mol x L(-1). PMID:19650499

Yang, Pei-hui; Wei, Wei; Cai, Huai-hong; Feng, Jing; Cai, Ji-ye

2009-05-01

367

Property of nano-SiO 2 \\/urea formaldehyde resin  

Microsoft Academic Search

In this paper, we discuss the effects of a nanometer silicon dioxide (nano-SiO2) coupling agent, dispersal methods and the amount of nano-SiO2\\/urea formaldehyde resin. The results of our study indicate that when nano-SiO2, using KH-550 silane as a coupling agent, was added to UF resin by discontinuous ultrasonic vibration, its properties improved\\u000a effectively. When the content of nano-SiO2 was below

Qiaojia Lin; Guidi Yang; Jinghong Liu; Jiuping Rao

2006-01-01

368

Spin-accumulation effect in magnetic nano-bridge  

Microsoft Academic Search

Large values of magnetoresistance experimentally observed in magnetic nano-contacts and nano-wires are explained in terms of spin accumulation. The investigation of the spin-accumulation effect in magnetic nano-contacts (Phys. Rev. Lett. 82 (1999) 2923) and nano-bridges (JETP Lett. 75 (10) (2002) 613), which are considered to be very promising for various spintronic applications, is presented. The two-dimensional spin-diffusion problem in a

A. V. Khvalkovskii; A. A. Zvezdin; K. A. Zvezdin; D. Pullini; P. Perlo

2004-01-01

369

Energetic nano-materials: Opportunities for enhanced performances  

Microsoft Academic Search

This paper deals with the contribution of nano-materials to the contemporary pyrotechnics science. The breakthroughs in this domain are illustrated by several examples of energetic nano-materials recently studied in our laboratory.The solidification of energetic phases in a porous matrix (Cr2O3) was used to prepare and to stabilize at nano-scale explosive particles. The thermo-chemical behaviour of RDX nano-particles strongly differs from

Denis Spitzer; Marc Comet; Christian Baras; Vincent Pichot; Nelly Piazzon

2010-01-01

370

Formation of Au nano-patterns on various substrates using simplified nano-transfer printing method  

NASA Astrophysics Data System (ADS)

For future device applications, fabrication of the metal nano-patterns on various substrates, such as Si wafer, non-planar glass lens and flexible plastic films become important. Among various nano-patterning technologies, nano-transfer print method is one of the simplest techniques to fabricate metal nano-patterns. In nano-transfer printing process, thin Au layer is deposited on flexible PDMS mold, containing surface protrusion patterns, and the Au layer is transferred from PDMS mold to various substrates due to the difference of bonding strength of Au layer to PDMS mold and to the substrate. For effective transfer of Au layer, self-assembled monolayer, which has strong bonding to Au, is deposited on the substrate as a glue layer. In this study, complicated SAM layer coating process was replaced to simple UV/ozone treatment, which can activates the surface and form the -OH radicals. Using simple UV/ozone treatments on both Au and substrate, Au nano-pattern can be successfully transferred to as large as 6 in. diameter Si wafer, without SAM coating process. High fidelity transfer of Au nano-patterns to non-planar glass lens and flexible PET film was also demonstrated.

Kim, Jong-Woo; Yang, Ki-Yeon; Hong, Sung-Hoon; Lee, Heon

2008-06-01

371

Improved extraordinary optical transmission though single nano-slit by nano-defocusing  

NASA Astrophysics Data System (ADS)

In this work, by using the finite difference time domain (FDTD) method, we have numerically studied the transmission properties of a composite structure consisting of a de-focusing tapered slit and nano-strip. For a fixed wavelength, the dependence of transmission efficiency of light on the structure parameters is demonstrated in detail. we have found that the extraordinary optical transmission through a single tapered metallic nano-slit is enhanced by placing a metallic nano-strip over it, in which tapered slit with large taper angle is used for de-focusing of light and be avoid of Fabry–Perot resonance in straight metallic nano-slit. It is shown that a suitable tapered slit assisted by nano-cavity-antenna can enhance the transmission by about 50% (compared with that in straight slit case). Furthermore, the parameters of the tapered slit (the taper angle and the taper length) hardly change the resonance in the horizontal nano-cavity. The transmission spectrum of the tapered slit can also be tuned by adjusting the taper angle. Such striking characteristic tapered slit has promising applications in designing optical nano-scale device.

Sun, Bin; Wang, Ling-Ling; Wang, Liu; Zhai, Xiang; Li, Xiao-Fei; Liu, Jian-Qiang

2013-12-01

372

Nano-scale chemical and biological sensors  

NASA Astrophysics Data System (ADS)

Nano-engineered devices with potential for trace level detection of chemical or biological species are investigated. The sensor system is a ChemFET device based on micro- and nano-scale silicon wires. The sensor response to changes in pH reveals a significantly higher sensitivity of nano-scale devices compared to micro-scale devices. By immobilizing DNA probe molecules on the silicon wire surface, the ChemFET devices are rendered specific to this DNA sequence. Differential measurements minimize the effects of non-specific binding. At a concentration of CDNA=10?M, two different single stranded 24-base DNA oligonucleotides have been clearly distinguished in the sensor response. DNA hybridization on the silicon wire surface is further corroborated by fluorescence spectroscopy and analysis of characteristic time constants in the sensors response.

Moller, Sven; Hinch, Garry D.; Duda, Kenneth J.; Kornilovitch, Pavel; Peters, Kevin F.; Ward, Kenneth; Wei, Qingqiao; Yang, Xioafeng

2005-11-01

373

Micro and Nano Systems for Space Exploration  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the use of micro and nano systems in Space exploration. Included are: an explanation of the rationales behind nano and micro technologies for space exploration, a review of how the devices are fabricated, including details on lithography with more information on Electron Beam (E-Beam) lithography, and X-ray lithography, a review of micro gyroscopes and inchworm Microactuator as examples of the use of MicroElectoMechanical (MEMS) technology. Also included is information on Carbon Nanotubes, including a review of the CVD growth process. These micro-nano systems have given rise to the next generation of miniature X-ray Diffraction, X-ray Fluorescence instruments, mass spectrometers, and terahertz frequency vacuum tube oscillators and amplifiers, scanning electron microscopes and energy dispersive x-ray spectroscope. The nanotechnology has also given rise to coating technology, such as silicon nanotip anti-reflection coating.

Manohara, Harish

2007-01-01

374

Mechanical Properties of Polymer Nano-composites  

NASA Astrophysics Data System (ADS)

Thermoset polymer composites are increasingly important in high-performance engineering industries due to their light-weight and high specific strength, finding cutting-edge applications such as aircraft fuselage material and automobile parts. Epoxy is the most widely employed thermoset polymer, but is brittle due to extensive cross-linking and notch sensitivity, necessitating mechanical property studies especially fracture toughness and fatigue resistance, to ameliorate the low crack resistance. Towards this end, various nano and micro fillers have been used with epoxy to form composite materials. Particularly for nano-fillers, the 1-100 nm scale dimensions lead to fascinating mechanical properties, oftentimes proving superior to the epoxy matrix. The chemical nature, topology, mechanical properties and geometry of the nano-fillers have a profound influence on nano-composite behavior and hence are studied in the context of enhancing properties and understanding reinforcement mechanisms in polymer matrix nano-composites. Using carbon nanotubes (CNTs) as polymer filler, uniquely results in both increased stiffness as well as toughness, leading to extensive research on their applications. Though CNTs-polymer nano-composites offer better mechanical properties, at high stress amplitude their fatigue resistance is lost. In this work covalent functionalization of CNTs has been found to have a profound impact on mechanical properties of the CNT-epoxy nano-composite. Amine treated CNTs were found to give rise to effective fatigue resistance throughout the whole range of stress intensity factor, in addition to significantly enhancing fracture toughness, ductility, Young's modulus and average hardness of the nano-composite by factors of 57%, 60%, 30% and 45% respectively over the matrix as a result of diminished localized cross-linking. Graphene, a one-atom-thick sheet of atoms is a carbon allotrope, which has garnered significant attention of the scientific community and is predicted to out-perform nanotubes. In the last few years, work has been done by researchers to study bulk mechanical properties of graphene platelets in polymer matrix. This thesis reports the extensive improvements observed in fatigue resistance and fracture toughness of epoxy using graphene platelet as a filler in very small quantities. Though significant property improvements like 75% increase in fracture toughness and 25-fold increase in fatigue resistance were observed for graphene epoxy nano-composites, the toughening mechanisms could not be delineated without thermo-mechanical and micro-mechanical tests. In this work, the bulk mechanical properties of graphene platelet-polymer nano-composites are studied and presented and the toughness mechanisms are identified by fractography, differential scanning calorimetry, and Raman spectroscopy; and then compared to predictions by theoretical models. Strong adherence to the matrix was found to be the key mechanism responsible for the effective reinforcement provided by graphene to the polymer. The strong graphene platelet-matrix interface also leads to extensive crack deflection, which was observed to be the major toughening mechanism in the nano-composite. In this thesis, the bulk mechanical property results are complemented by in-depth characterization of filler-polymer interfacial interactions and interphase formation using a battery of techniques including Raman spectroscopy and atomic force microscopy. Theoretical and empirical models proposed by Faber & Evans and Pezzotti were critically studied and applied. Pezzotti's model was found to corroborate well with experimental results and provided insight into enhancement mechanisms and explains the mechanisms underpinning the toughness loss at high graphene platelet weight fraction. The thesis provides conclusive evidences for the superiority of graphene as a filler for reinforcing polymer matrices. In conclusion, the thesis presents a thorough investigation of one- and two-dimensional carbon nanomaterials as fillers for high-performance polymer nano-compo

Srivastava, Iti

375

Hardness of Electrodeposited Nano-Nickel Revisited  

NASA Astrophysics Data System (ADS)

In the past, hardness measurements on nanocrystalline metals were limited to Vickers microhardness and nano-indentation tests, mainly due to sample size/thickness limitations. On the other hand, most industries require hardness values on the Rockwell scale and make extensive use of hardness conversion relationships for various hardness scales. However, hardness conversions currently do not exist for nanocrystalline metals. With recent advances in electrodeposition technology, thicker specimens with a wide range of grain sizes can now be produced. In this study, the relationships between Vickers and Rockwell hardness scales have been developed for such materials. In addition, hardness indentations were used to gain further insight into the work hardening of nanocrystalline and polycrystalline nickel. Vickers microhardness and nano-indentation profiles below large Rockwell indentations showed that polycrystalline nickel exhibited considerable strain hardening, as expected. On the other hand, for nanocrystalline nickel the micro-Vickers and nano-indentations hardness profile showed low strain hardening capacity.

Tang, Bill Tsz Fai

376

Interactive Nano-visualization in Science & Engineering Education  

NSDL National Science Digital Library

This project has developed learning resources that include nano-scale science and technology into the high school and introductory college curricula. Resources include an online scanning-probe microscope, a wide range of images and animations illustrating material and chemical properties on the nano-scale, and online learning modules on material science and nano-scale biological science.

Ramakrishna, B. L.

2005-03-16

377

Nano liquid-metal fluid as ultimate coolant  

Microsoft Academic Search

We proposed for the first time the concept of the nano liquid-metal fluid, aiming to establish an engineering route to make the highest conductive coolant. Using several widely accepted theoretical models for characterizing the nano fluid, the thermal conductivity enhancement of the liquid-metal fluid due to addition of more conductive nano particles was predicted. Further, the effects of particle size,

Kun-Quan Ma; Jing Liu

2007-01-01

378

Colloidal CdTe Nano Crystals Synthesis and Characterization.  

National Technical Information Service (NTIS)

Synthesis of CdTe nano crystals (NCs) in uniform sizes and in good quality was performed in our nano lab and further characterized by absorption spectra, photoluminescence (PL), and atomic force microscopy (AFM). In this growth procedure, CdTe nano crysta...

F. Semendy G. Jaganathan I. Bhat N. Dhar S. Trivedi

2008-01-01

379

Self Assembly of Nano Metric Metallic Particles for Realization of Photonic and Electronic Nano Transistors  

PubMed Central

In this paper, we present the self assembly procedure as well as experimental results of a novel method for constructing well defined arrangements of self assembly metallic nano particles into sophisticated nano structures. The self assembly concept is based on focused ion beam (FIB) technology, where metallic nano particles are self assembled due to implantation of positive gallium ions into the insulating material (e.g., silica as in silicon on insulator wafers) that acts as intermediary layer between the substrate and the negatively charge metallic nanoparticles.

Shahmoon, Asaf; Limon, Ofer; Girshevitz, Olga; Zalevsky, Zeev

2010-01-01

380

Construction of coherent nano quantitative structure-properties relationships (nano-QSPR) models and catastrophe theory.  

PubMed

The structure one can associate to coherent nano-quantitative structure-properties relationship (nano-QSPR) models is briefly discussed. Such nano-QSPR model functions are described as possessing three parts: a particle size polynomial; a typical QSPR function; and a special effects function. The expected behaviour of the particle size part is discussed from the point of view of catastrophe theory, in this way providing a plausible general picture about the emergence of new properties of nanoparticles and holographic location of information content. PMID:21999713

Carbó-Dorca, R; Besalú, E

2011-10-01

381

Generation of Nano-Catalyst Particles by Spinodal Nano-Decomposition in Perovskite  

Microsoft Academic Search

A new mechanism of nano-catalyst generation based on the spinodal nano-decomposition in self-regenerating perovskite catalysts for automotive-emissions control is proposed. To demonstrate existence of the spinodal nano-decomposition in real perovskite catalysts, we performed first-principles calculations to evaluate the free energy of La(Fe1-xPdx)O3 and La(Fe1-xRhx)O3. The result indicates appearance of a spinodal region in the phase diagram of each material. Formation

Hidetoshi Kizaki; Koichi Kusakabe; Soichiro Nogami; Hiroshi Katayama-Yoshida

2008-01-01

382

Indentation and scratch behavior of nano-SiO 2\\/polycarbonate composite coating at the micro\\/nano-scale  

Microsoft Academic Search

The mechanical and tribological performances of polycarbonate film and nano-SiO2\\/polycarbonate composite coating are studied with micro\\/nano-scale indentation and scratch tests using Hysitron TriboIndenter. The experimental results show that the hardness and stiffness are increased apparently after the addition of nano-SiO2. The scratch tests indicate that the nano-SiO2\\/polycarbonate coating exhibits smaller scratch depth and lower frictional coefficient. Combined with the examination

Z. Z. Wang; P. Gu; Z. Zhang

2010-01-01

383

Theranostic Au Cubic Nano-aggregates as Potential Photoacoustic Contrast and Photothermal Therapeutic Agents  

PubMed Central

Multifunctional nanostructures combining diagnosis and therapy modalities into one entity have drawn much attention in the biomedical applications. Herein, we report a simple and cost-effective method to synthesize a novel cubic Au nano-aggregates structure with edge-length of 80 nm (Au-80 CNAs), which display strong near-infrared (NIR) absorption, excellent water-solubility, good photothermal stability, and high biocompatibility. Under 808 nm laser irradiation for 5 min, the temperature of the solution containing Au-80 CNAs (100 ?g/mL) increased by ~38 °C. The in vitro and in vivo studies demonstrated that Au-80 CNAs could act as both photothermal therapeutic (PTT) agents and photoacoustic imaging (PAI) contrast agents, indicating that the only one nano-entity of Au-80 CNAs shows great potentials for theranostic applications. Moreover, this facile and cost-effective synthetic method provides a new strategy to prepare stable Au nanomaterials with excellent optical properties for biomedical applications.

Hu, Juan; Zhu, Xianglong; Li, Hui; Zhao, Zhenghuan; Chi, Xiaoqin; Huang, Guoming; Huang, Dengtong; Liu, Gang; Wang, Xiaomin; Gao, Jinhao

2014-01-01

384

Study of nano imprinting using soft lithography on Krafty glue & PVDF polymer thin films  

NASA Astrophysics Data System (ADS)

The present work reveals soft lithography strategy based on self assembly and replica molding for carrying out micro and nanofabrication. It provides a convenient, effective and very low cost method for the formation and manufacturing of micro and nano structures. Al-layer of compact disc (sony CD-R) used as a stamp with patterned relief structures to generate patterns and structures with pattern size of 100nm height, 1.7 ?m wide. In literature, PDMS (Polydimethylsiloxane) solution is widely used to get negative copy of the Al-layer. In this work, we have used inexpensive white glue (Polyvinylacetate + water), 15gm (?5) and PVDF (Polyvinylidene difluoride) spin coated films and successfully transferred the nano patterns of Al layer on to white glue and PVDF films.

Sankar, M. S. Ravi; Gangineni, Ramesh Babu

2014-04-01

385

Nano-Scale Device Simulations Using PROPHET  

NSDL National Science Digital Library

These two lectures are aimed to give a practical guide to the use of a general device simulator (PROPHET) available on nanoHUB. PROPHET is a partial differential equation (PDE) solver that offers users the flexibility of integrating new models and equations for their nano-device simulations. The first lecture covers the basics of PROPHET, including the set-up of simulation structures and parameters based on pre-defined PDE systems. The second lecture uses examples to illustrate how to build user-defined PDE systems in PROPHET.

Dutton, Robert; Liu, Yang

2010-11-26

386

Olefin metathesis in nano-sized systems  

PubMed Central

Summary The interplay between olefin metathesis and dendrimers and other nano systems is addressed in this mini review mostly based on the authors’ own contributions over the last decade. Two subjects are presented and discussed: (i) The catalysis of olefin metathesis by dendritic nano-catalysts via either covalent attachment (ROMP) or, more usefully, dendrimer encapsulation – ring closing metathesis (RCM), cross metathesis (CM), enyne metathesis reactions (EYM) – for reactions in water without a co-solvent and (ii) construction and functionalization of dendrimers by CM reactions.

Diallo, Abdou K; Gatard, Sylvain; Liang, Liyuan; Ornelas, Catia; Martinez, Victor; Mery, Denise; Ruiz, Jaime

2011-01-01

387

Magnetic bead detection using nano-transformers.  

PubMed

A novel scheme to detect magnetic beads using a nano-scale transformer with a femtoweber resolution is reported. We have performed a Faraday's induction experiment with the nano-transformer at room temperature. The transformer shows the linear output voltage responses to the sinusoidal input current. When magnetic beads are placed on the transformer, the output responses are increased by an amount corresponding to the added magnetic flux from the beads when compared with the case of no beads on the transformer. In this way, we could determine whether magnetic beads are on top of the transformer in a single particle level. PMID:20972313

Kim, Hyung Kwon; Hwang, Jong Seung; Hwang, Sung Woo; Ahn, Doyeol

2010-11-19

388

A new approach to synthesize nano WC  

NASA Astrophysics Data System (ADS)

Tungsten carbide (WC) is extensively used in cutting and mining tools, dies and in wear resistance parts. The recent application of WC as electrocatalyst in fuel cells to replace costly nobel metal platinum (Pt) has further increased its demand. Its catalytic and mechanical properties are improved with the reduction of particle size in a nanometric range. The nano WC is synthesized from the pure precursor(s) which makes its production costly. In this work, we report a new process to get nano WC directly from the scheelite (CaWO4) ore. The powders were characterized by XRD, SEM and HRTEM.

Singh, Harjinder; Pandey, O. P.

2013-06-01

389

Spatio-temporal trends in tree and tall shrub cover in the Eurasian Low Arctic: evidence from 1960s and contemporary satellite imagery and ground observations  

NASA Astrophysics Data System (ADS)

Patterns of tree and tall shrub occurrence form conspicuous and dynamic ecological boundaries across arctic regions. Expansion of trees and shrubs into tundra-dominated areas is one of the principal changes to arctic land cover expected with climatic warming, and there is evidence that ecological state-shifts are already occurring in ecotones of the North American Low Arctic. The ubiquity of these state-shifts across the circumpolar Low Arctic is unclear, however, because few data exist for the vast Eurasian continent. Large-scale, synchronous expansions have occurred in the past (e.g., mid-Holocene) and associated changes to land surface-atmosphere interactions could have far-reaching effects on atmospheric circulation and global climate. This study is quantifying state-level vegetation change in geographic and altitudinal tundra ecotones at ~25 sites in northern Eurasia and Alaska using comparisons of circa 1965 Corona and contemporary high-resolution satellite photography. Corona was the world’s first operational satellite surveillance system and offers a readily available data source for land-surface change studies over a ~40 year temporal interval. Remote sensing and ground-based data indicate that mean annual temperatures have increased over the last ~50 years at all study sites, although the magnitude of warming varies (~1.5 - 4 °C). The degree to which patterns of vegetation change are shared among sites will indicate the ubiquity of ecological state-shifts in the Low Arctic, as well as the relative influence of large-scale forcing mechanisms (e.g., climate change) and local environmental controls (e.g., disturbance regime, geomorphology) on tree and tall shrub expansion. Preliminary findings indicate that tall shrublands have expanded at several sites in northwestern and far eastern Siberia. Recent expansion is most apparent on floodplains, uplands, and drained lake basins. Ground data indicate that dramatic expansion of alder shrubs at a tree-line site near Kharp, northwest Siberia has occurred in areas affected by an antecedent high-intensity wildfire that removed the surface organic layer. Additionally, alder recruitment both inside and outside of the burn is concentrated on disturbed mineral soils associated with cryogenic patterned-ground features. On the southern Yamal Peninsula, Russia, comparison of 1968 Corona and 2009 aerial photographs indicate that alders have colonized retransported sands derived from barren uplands near Ozero Yaroto. Additionally, alders and willows have rapidly colonized fluvial terraces and point bars on the Tanlova River that were barren in 1968. These findings indicate that local-scale disturbance events that create mineral-dominated edaphic conditions have promoted recent shrubification and enhanced productivity in parts of the Low Arctic.

Frost, G. V.; Epstein, H.; Walker, D. A.

2009-12-01

390

Effects of supplementing endophyte-infected tall fescue with sainfoin and polyethylene glycol on the physiology and ingestive behavior of sheep.  

PubMed

Tannins in sainfoin (Onobrychis viciifolia) may bind to alkaloids in endophyte-infected tall fescue [E+; Lolium arundinaceum (Schreb.) Darbysh.] and attenuate toxicosis. If so, supplementing E+ with sainfoin will increase use of E+ by sheep, and polyethylene glycol (PEG)-a polymer that selectively binds to tannins-will reduce such response. To test these predictions, thirty-six 2-mo-old lambs were randomly assigned to 3 treatments (12 lambs/treatment). During exposure, all lambs were individually penned and fed E+ supplemented with beet pulp (CTRL), fresh-cut sainfoin and beet pulp (SAIN), or fresh-cut sainfoin plus PEG mixed in beet pulp (SAIN+PEG). Feed intake was measured daily. Rectal temperatures and jugular blood samples were taken at the beginning and end of exposure. After exposure, all lambs were offered choices between endophyte-free tall fescue (E-) and orchardgrass, and preference for E- was assessed. Then, all lambs were allowed to graze a choice of E+ and sainfoin or a monoculture of E+. The foraging behavior of lambs was recorded. When sainfoin was in mid-vegetative stage, lambs in SAIN ingested more E+ than lambs in CTRL (P = 0.05), but no differences were detected between lambs in SAIN+PEG and CTRL (P = 0.12). Sainfoin supplementation improved some physiological parameters indicative of fescue toxicosis. Lambs in SAIN had lower rectal temperatures (P = 0.02), greater numbers of leukocytes (P < 0.001) and lymphocytes (P = 0.03), and greater plasmatic concentrations of globulin (P = 0.009) and prolactin (P = 0.019) than lambs in CTRL. Some of these differences were offset by the SAIN+PEG treatment. When lambs were offered choices between E- and orchardgrass, only lambs in SAIN had greater intake of E- than lambs in CTRL (P < 0.001). When lambs were allowed to graze a choice of E+ and sainfoin, all treatments used E+ to the same extent (P > 0.05). On the other hand, when they grazed on a monoculture of E+, lambs in SAIN+PEG showed greater acceptance of E+ than lambs in SAIN or in CTRL (P < 0.05). In summary, sainfoin supplementation alleviated several of the classic signs of fescue toxicosis and increased intake of endophyte-infected tall fescue. Tannins in sainfoin partially accounted for this benefit since feeding a polymer that selectively binds to tannins (PEG) attenuated some these responses. However, sainfoin supplementation during initial exposure to E+ did not lead to an increased preference for E+ during grazing. PMID:24664564

Catanese, F; Distel, R A; Villalba, J J

2014-02-01

391

Change in hydraulic properties and leaf traits in a tall rainforest tree species subjected to long-term throughfall exclusion in the perhumid tropics  

NASA Astrophysics Data System (ADS)

A large-scale replicated throughfall exclusion experiment was conducted in a pre-montane perhumid rainforest in Sulawesi (Indonesia) exposing the trees for two years to pronounced soil desiccation. The lack of regularly occurring dry periods and shallow rooting patterns distinguish this experiment from similar experiments conducted in the Amazonian rainforest. We tested the hypotheses that a tree's sun canopy is more affected by soil drought than its shade crown, making tall trees particularly vulnerable even under a perhumid climate, and that extended drought periods stimulate an acclimation in the hydraulic system of the sun canopy. In the abundant and tall tree species Castanopsis acuminatissima (Fagaceae), we compared 31 morphological, anatomical, hydraulic and chemical variables of leaves, branches and the stem together with stem diameter growth between drought and control plots. There was no evidence of canopy dieback. However, the drought treatment led to a 30 % reduction in sapwood-specific hydraulic conductivity of sun canopy branches, possibly caused by the formation of smaller vessels and/or vessel filling by tyloses. Drought caused an increase in leaf size, but a decrease in leaf number, and a reduction in foliar calcium content. The ?13C and ?18O signatures of sun canopy leaves gave no indication of a permanent down-regulation of stomatal conductance during the drought, indicating that pre-senescent leaf shedding may have improved the water status of the remaining leaves. Annual stem diameter growth decreased during the drought, while the density of wood in the recently produced xylem increased in both the stem and sun canopy branches (marginally significant). The sun canopy showed a more pronounced drought response than the shade crown indicating that tall trees with a large sun canopy are more vulnerable to drought stress. We conclude that the extended drought prompted a number of medium- to long-term responses in the leaves, branches and the trunk, which may have reduced drought susceptibility. However, unlike a natural drought, our drought simulation experiment was carried out under conditions of high humidity, which may have dampened drought induced damages.

Schuldt, B.; Leuschner, C.; Horna, V.; Moser, G.; Köhler, M.; van Straaten, O.; Barus, H.

2011-08-01

392

Automatic Morphological Categorisation of Carbon Black Nano-aggregates  

Microsoft Academic Search

\\u000a Nano-technology is the study of matter behaviour on atomic and molecular scale (i.e. nano-scale). In particular, carbon black\\u000a is a nano-material generally used for the reinforcement of rubber compounds. Nevertheless, the exact reason behind its success\\u000a in this concrete domain remains unknown. Characterisation of rubber nano-aggregates aims to answer this question. The morphology\\u000a of the nano-aggregate takes an important part

Juan López-de-Uralde; Iraide Ruiz; Igor Santos; Agustín Zubillaga; Pablo Garcia Bringas; Ana Okariz; Teresa Guraya

2010-01-01

393

Functionally Graded Materials using Plasma Spray with Nano Structured Ceramic  

NASA Astrophysics Data System (ADS)

In this paper, nano structured FGM was fabricated using DC plasma spray technique. Nano structured and micro structured powder were used as the feeding powder with steel substrate. The spray parameters was optimized and characterisation of nano-ceramic FGM and micro-ceramic FGM were done using bending test and micro-hardness test. Experimental results have shown that the nano-structured FGM exhibit 20% improvement flexure strength and 10% in hardness. A comparison was made between sintered micro ceramic tile and nano ceramic FGM using simple drop test method.

Sioh, E. L.; Tok, A. I. Y.

2013-03-01

394

Orientated Nano-Composites: Relationships Between Nano-Structure and Mechanical Properties.  

National Technical Information Service (NTIS)

Epoxy nano-composites have been manufactured using a range of modifiers, including organoclays, silica nanoparticles and carbon nanotubes. The mechanical and fracture properties of these materials have been investigated, and the structure/property relatio...

A. C. Taylor A. J. Kinloch

2004-01-01

395

Nano-composite organic devices  

NASA Astrophysics Data System (ADS)

Sufficient advances have been made in conjugated organic materials within the last ten years so that applications such as light emitting diodes, organic sensors, organic lasers, and other devices are nearing commercial viability. However, the development of organics for high performance electronic and photonic technologies is still faced with significant challenges due to low and asymmetric carrier mobilities, oxidative changes in the metal-polymer interface, and photo-oxidation via energy transfer from the polymer triplet exciton. Traditionally, "doping" of the conjugated polymers to enhance performance has consisted of chemical doping, polymer-dye blending, or polymer-polymer blending. This research focuses on an alternate scheme of using single wall carbon nanotubes as dopants to form charge transfer nano-composites. The addition of single wall nanotubes to the polymer results in significant morphological and electronic changes to the composite. We present one of the first manuscripts showing ordering of a polymer on a single wall nanotube and the resultant modification of electronic states in the valence band of the tube. The electronic effects of single wall nanotubes in conjugated polymer composites are further investigated by constructing double layer organic light emitting diodes with a composite emissive layer. Charge transport was shown to be modified via the addition of shallow trapping states near the valence band of the polymer, and trap energies were calculated to be less than the exciton binding energy (<0.4 eV). The modification to the mobility of the device by the addition of the nanotubes moves the recombination zone in the device, and this can be used for color tuning of a single pixel. Devices were also constructed with single wall nanotube composite buffer layers. The addition of the nanotubes to the buffer layer resulted in a significant reduction in the electroluminescence of the device without changing the photoluminescence of the films indicating that the effect is electronic. The I˜V 2 power law dependence at low voltages suggests that the reduction in electroluminescence in these devices is also due to trapping states being introduced into the buffer polymer.

Czerw, Richard

396

Microfluidic size selective growth of palladium nano-particles on carbon nano-onions.  

PubMed

Size selective growth of palladium nano-particles 2-7 nm in diameter on the surface of carbon nano-onions (CNOs) (derived from catalytic cracking of methane) in water involves pretreating the CNOs with p-phosphonic acid calix[8]arene then H(2)PdCl(4) followed by dynamic thin film processing under hydrogen in a vortex fluidic device. PMID:22957341

Yasin, Faizah Md; Boulos, Ramiz A; Hong, Boon Yong; Cornejo, Andrew; Iyer, K Swaminathan; Gao, Lizhen; Chua, Hui Tong; Raston, Colin L

2012-10-18

397

Characteristics of silicon nano wire as piezoresistor for nano electro mechanical systems  

Microsoft Academic Search

In order to confirm ability of silicon nano wire piezoresistors as sensing element of mechanical sensors, current-voltage (I-V) characteristics and the piezoresistive effect were investigated. Electron beam (EB) direct writing and RIE were used for fabrication. Fabricated polycrystalline Si (poly-Si) nano wire piezoresistors have triangular or trapezoid cross sections. The minimum width is 53 nm and thickness is 32 nm.

Toshiyuki Toriyama; Yasutada Tanimoto; Susumu Sugiyama

2001-01-01

398

Nano-Fiber Reinforced Enhancements in Composite Polymer Matrices  

NASA Technical Reports Server (NTRS)

Nano-fibers are used to reinforce polymer matrices to enhance the matrix dependent properties that are subsequently used in conventional structural composites. A quasi isotropic configuration is used in arranging like nano-fibers through the thickness to ascertain equiaxial enhanced matrix behavior. The nano-fiber volume ratios are used to obtain the enhanced matrix strength properties for 0.01,0.03, and 0.05 nano-fiber volume rates. These enhanced nano-fiber matrices are used with conventional fiber volume ratios of 0.3 and 0.5 to obtain the composite properties. Results show that nano-fiber enhanced matrices of higher than 0.3 nano-fiber volume ratio are degrading the composite properties.

Chamis, Christos C.

2009-01-01

399

Sub-Diffraction Nano Manipulation Using STED AFM  

PubMed Central

In the last two decades, nano manipulation has been recognized as a potential tool of scientific interest especially in nanotechnology and nano-robotics. Contemporary optical microscopy (super resolution) techniques have also reached the nanometer scale resolution to visualize this and hence a combination of super resolution aided nano manipulation ineluctably gives a new perspective to the scenario. Here we demonstrate how specificity and rapid determination of structures provided by stimulated emission depletion (STED) microscope can aid another microscopic tool with capability of mechanical manoeuvring, like an atomic force microscope (AFM) to get topological information or to target nano scaled materials. We also give proof of principle on how high-resolution real time visualization can improve nano manipulation capability within a dense sample, and how STED-AFM is an optimal combination for this job. With these evidences, this article points to future precise nano dissections and maybe even to a nano-snooker game with an AFM tip and fluorospheres.

Chacko, Jenu Varghese; Canale, Claudio; Harke, Benjamin; Diaspro, Alberto

2013-01-01

400

Polymer nanotechnology applied to polymeric nano-soft-materials  

NASA Astrophysics Data System (ADS)

We have been developing new techniques to evaluate polymer nano-alloys and nano-composites. This "nanotechnology" can be classified into nano-three dimensional (3D) measurement, nano-physical properties evaluation systems, and nano-spectroscopy. As for the nano-3D measurement, we developed polymer oriented energy-filtered 3D transmission electron microscopy. With this method, we can access important 3D structural and elemental information that cannot be obtainable from ordinary TEM. Nano-physical properties evaluation systems were also established by developing atomic force microscopy force-distance curve measurement. The distribution of mechanical properties such as Young's modulus and adhesive energy was quantitatively obtained on high lateral resolution. These methods give new pieces of information unobtainable by the conventional techniques on polymer nanotechnology. Several results are shown here.

Nishi, T.; Fujinami, S.; Nakajima, K.; Sugimori, H.; Hatta, M.; Weber, M.; Jinnai, H.

2009-08-01

401

The Internet of nano-things  

Microsoft Academic Search

Nanotechnology promises new solutions for many applications in the biomedical, industrial and military fields as well as in consumer and industrial goods. The interconnection of nanoscale devices with existing communication networks and ultimately the Internet defines a new networking paradigm that is further referred to as the Internet of Nano-Things. Within this context, this paper discusses the state of the

I. F. Akyildiz; J. M. Jornet

2010-01-01

402

Growth of decorated carbon nano-tubes  

Microsoft Academic Search

Decomposition of methane in a nitrogen atmosphere using bias-enhanced hot filament chemical vapour deposition results in the growth of nitrogenated carbon tubes. Different shapes were formed ranging from spherical aggregates to twisted nano-tubes. All these structures were grown direct onto pure Si wafer. Glow discharge optical emission spectroscopy reveals the presence of tungsten carbide impurities at the interface. Graphitic sheets

Ralph Kurt; Ayatollah Karimi; Volker Hoffmann

2001-01-01

403

Yttria Nano-Particle Reinforced CP Titanium.  

National Technical Information Service (NTIS)

Literature shows that doubling of tensile properties is achievable via nano-sized yttria (Y203) dispersion in titanium. These initial studies reported proof of concept using small laboratory-scale samples produced via arc- melting but further studies to e...

S. Tamirisa

2011-01-01

404

Biophysical Dynamics Laboratories Nano-Biophotonics Group  

NSDL National Science Digital Library

The Biophysical Dynamics Laboratories Nano-Biophotonics Group, of the Graduate School of Frontier Biosciences at Osaka University, addresses its applications of nanotechnology and non-linear spectroscopy to the biology field. Visitors can find synopses of its four main research projects and a list of publications.

1969-12-31

405

Characterization of thermally conductive epoxy nano composites  

Microsoft Academic Search

This work aims to develop an anisotropic conductive adhesive (ACA) paste with improved thermal conductivity. ACA consists of a polymer based resin and conductive filler particles. We introduce an electrically insulating but thermally conductive phase into the adhesive. Nano and micro scale particles of alumina oxide, silicon carbide and carbon nanotubes are used with and without surface treatment. The thermal

Lisa Ekstrand; Helge Kristiansen; Johan Liu

2005-01-01

406

Nano-domains segmentation on AFM images  

NASA Astrophysics Data System (ADS)

The goal of this article is to present a new automatic processing allowing a segmentation of AFM images with the aim of obtaining with precision the dimensions of nano-domains. The proposed treatment is based on the wedding of the multiresolution analysis with a thresholding method. Results obtained on real data are proposed.

Luciani, X.; Patrone, L.; Courmontagne, P.

2006-03-01

407

Organic Solvent Dispersed Nano-Talc Slurry.  

National Technical Information Service (NTIS)

The invention provides high surface area talc compositions by a novel hybrid milling method or soaking method. The hybrid milling method comprises dry milling talc powder followed by mixing with water and wet milling to provide a nano-talc slurry with hig...

J. He Q. Zhong

2004-01-01

408

Coulomb blockade in silicon nano-pillars  

NASA Astrophysics Data System (ADS)

We have investigated the current-voltage characteristics of nano-pillars of polycrystalline silicon with two 2-3 nm thick silicon nitride tunnel barriers. Pillars with diameters between 45 and 100 nm showed a Coulomb blockade region and Coulomb staircase at 4.2 K.

Pooley, D. M.; Ahmed, H.; Mizuta, H.; Nakazato, K.

1999-04-01

409

Micro and nano structurization of semiconductor surfaces  

Microsoft Academic Search

The techniques of micro and nano structurization of surfaces of various materials are utilized in electronics and medicine. Such procedure as wet and dry etching allows to fabricate protruded or recessed micro and nanostructures on the surface. In the paper some examples of utilization of a surface structurization, known from literature, are described. Some structurization methods and experimental results for

A. GÓRECKA-DRZAZGA

410

Nano Air Vehicles: A Technology Forecast.  

National Technical Information Service (NTIS)

This paper documents the result of a future technology forecast study to determine when operationally useful nano-air vehicles (NAVs) will be achieved. This was accomplished as part of the Blue Horizons Research Team tasked by the Chief of Staff of the Un...

W. A. Davis

2007-01-01

411

Photothermal microscopy of nano-objects  

NASA Astrophysics Data System (ADS)

The further development of a time-resolved photothermal (PT) method for sensing nano-scale absorbing targets is presented. This method is based on irradiation of nano-targets with a short laser pulse and time-resolved PT visualization of laser-induced thermal effects around targets. It is accomplished with a second probe beam that senses the target with an adjustable time delay after the pump laser pulse. The practical capability of this new approach is demonstrated for visualization of nano-scale gold particles (2-250 nm), liposomes (30-90 nm), Neutral Red (NR) particles (30-500 nm), and polystyrene beads as a calibration tool, with a tunable parametric pulse laser-OPO (420-570 nm, 0.10300 ?J, 8-ns width) as a pump laser and Raman-Shifter (639 nm, 13 ns width, 10 nJ) as a probe laser with a tunable delay of the probe pulse relative to thepump pulse in the range of 0-5000 ns. The further development of our PT technique is discussed with a focus on visualization of nano-scale absorbing zones during laser-cell interaction.

Zharov, Vladimir P.; Lapotko, Dmitri

2003-06-01

412

Green Chemistry by Nano-Catalysis  

EPA Science Inventory

The approach of using MW technique with nano-catalysis and benign aqueous reaction medium can offer an extraordinary synergistic effect with greater potential than these three individual components in isolation. To illustrate the ??proof-of-concept?? of this ?Green and Sustainabl...

413

We Scream for Nano Ice Cream  

ERIC Educational Resources Information Center

There is a wide range of new products emerging from nanotechnology, and "nano ice cream" is an easy one that you can use to teach topics from surface area to volume applications. In this activity, students learn how ice cream can be made smoother and creamier tasting through nanoscience. By using liquid nitrogen to cool the cream mixture, students…

Jones, M. Gail; Krebs, Denise L.; Banks, Alton J.

2011-01-01

414

Report of a female patient with mental retardation and tall stature due to a chromosomal rearrangement disrupting the OPHN1 gene on Xq12  

PubMed Central

We report on a patient with mental retardation, seizures and tall stature with advanced bone age in whom a de novo apparently balanced chromosomal rearrangement 46,XX,t(X;9)(q12;p13.3) was identified. Using array CGH on flow-sorted derivative chromosomes (array painting) and subsequent FISH and qPCR analysis, we mapped and sequenced both breakpoints. The Xq12 breakpoint was located within the gene coding for oligophrenin 1 (OPHN1) whereas the 9p13.3 breakpoint was assigned to a non-coding segment within a gene dense region. Disruption of OPHN1 by the Xq12 breakpoint was considered the major cause of the abnormal phenotype observed in the proband.

Menten, Bjorn; Buysse, Karen; Vermeulen, Stefan; Meersschaut, Valerie; Vandesompele, Jo; Ng, Bee L.; P.Carter, Nigel; Mortier, Geert R.; Speleman, Frank

2009-01-01

415

Study of turbulent natural convection in a tall differentially heated cavity filled with either non-participating, participating grey and participating semigrey media  

NASA Astrophysics Data System (ADS)

Turbulent natural convection in a tall differentially heated cavity of aspect ratio 5:1, filled with air under a Rayleigh number based on the height of 4.5·1010 is studied numerically. Three different situations have been analysed. In the first one, the cavity is filled with a transparent medium. In the second one, the cavity is filled with a semigrey participating mixture of air and water vapour. In the last one the cavity contains a grey participating gas. The turbulent flow is described by means of Large Eddy Simulation (LES) using symmetry-preserving discretizations. Simulations are compared with experimental data available in the literature and with Direct Numerical Simulations (DNS). Surface and gas radiation have been simulated using the Discrete Ordinates Method (DOM). The influence of radiation on fluid flow behaviour has been analysed.

Capdevila, R.; Lehmkuhl, O.; Colomer, G.; Perez-Segarra, C. D.

2012-11-01

416

Localization of the chromosome 11 breakpoint in a translocation t(4;11)(q21;p15) in T cell acute lymphocytic leukemia (T-ALL)  

SciTech Connect

The identification of genes located at the breakpoints of chromosomal translocations has been invaluable in determining the pathogenesis of hematogical malignancies. We have investigated the translocation, t(4;11)(q21;p14-15) in a T-ALL patient. Four cases with a similar translocation have been reported; three at diagnosis and one as a secondary cytogenetic change. As a first step towards cloning of the breakpoint sequences, we isolated a somatic cell hybrid containing the der(4) translocation chromosome. The hybrid allowed us to determine the markers flanking the chromosome 11 breakpoint position. The breakpoint was localized to band 11p15.5 between the genes for interferon-like growth factor II (IGF2) and the M1 subunit of ribonucleotide reductase (RRM1) by PCR. Cosmid probes from this region were then used to further localize the breakpoint to a region adjacent to RRM1 by fluorescent in situ hybridization (FISH).

Dobrovic, A.; Peters, G.B.; Finch, J. [Queen Elizabeth Hospital, Woodville (Australia)] [and others

1994-09-01

417

Biomedical applications of nano-antioxidant.  

PubMed

For centuries now, antioxidants have been known to provide better health by neutralizing the free radicals which are continuously produced in the human body. In normal circumstances, self-antioxidant defense system of the human body is capable of quantitatively managing the free radicals. However, in certain cases, which are at the threshold of developing diseases like diabetes and Alzheimer's, the human body calls for an external source of antioxidants. Since orally delivered antioxidants are easily destroyed by acids and enzymes present in the human system, only a small portion of what is consumed actually gets absorbed. Hence, there is a recognized and urgent need to develop effective methods for efficiently delivering antioxidants to the required sites. This chapter provides an in-depth overview and analysis of two such methods and processes-nano-encapsulation and nano-dendrimers. Among the various nanoscale delivery mechanisms, nano-encapsulation has emerged as a key and efficient delivery process. Designed as a spongelike polymer, nano-encapsulated antioxidants provide a protective vehicle which keeps antioxidants from being destroyed in the human gut and ensures their better absorption in the digestive tract. In fact, the nano-capsules bind themselves to the intestinal walls and pour antioxidants directly into the intestinal cells, which allow them to be absorbed directly into the blood stream. Another distinguished and popular mode for delivering antioxidants is that of nano-polymers known as dendrimers. Dendrimers involve multiple branches and sub-branches of atoms radiating out from a central core. Dendrimers afford a high level of control over their architectural design, including their size, shape, branching length or density, and surface functionality. Such flexibility makes these nanostructures ideal carriers in biomedical applications such as drug delivery, gene transfection, and imaging. Antioxidant dendrimers, made out of numerous units of antioxidants connected with each other in a branched fashion, provide numerous possible sites to couple with an active species and have enhanced free radicals scavenging potency. These dendrimer chains are biocompatible, biodegradable with nontoxic degradation products, and well suited for targeted drug delivery and other biomedical applications. Recent successes in simplifying and optimizing the synthesis of dendrimers, such as the "lego" and "click" approaches, provide a large variety of structures while at the same time reducing the cost of their production. The use of these highly branched, nanometer-sized, polymeric materials as nano-antioxidants for prevention and treatment of human diseases, associated with oxidative stress, is of immense public health relevance globally. PMID:23740118

Watal, Geeta; Watal, Aparna; Rai, Prashant Kumar; Rai, Devendra Kumar; Sharma, Gaurav; Sharma, Bechan

2013-01-01

418

Simultaneous overexpression of both CuZn superoxide dismutase and ascorbate peroxidase in transgenic tall fescue plants confers increased tolerance to a wide range of abiotic stresses.  

PubMed

To mitigate the oxidative damage inflicted by biotic or abiotic stresses, plants have evolved complex anti-oxidative defense mechanisms that involve induction of antioxidant and anti-oxidative enzymes, such as superoxide dismutase (SOD) and ascorbate peroxidase (APX). To determine whether overexpression of the genes encoding copper-zinc SOD (CuZnSOD) and APX in plants is capable of decreasing reactive oxygen species (ROS) produced in response to abiotic stresses, we generated transgenic tall fescue plants expressing the CuZnSOD and APX genes in chloroplasts under the control of the oxidative stress-inducible promoter, sweet potato peroxidase anionic 2 (SWPA2). Transgenic plants were generated by Agrobacterium-mediated genetic transformation, and genotypes were confirmed by DNA blot analysis. Transgenic plants were exposed to several ROS-generating abiotic stresses, such as methyl viologen (MV), H(2)O(2), and the heavy metals copper, cadmium, and arsenic, and their tolerance was evaluated. High levels of CuZnSOD and APX gene transcripts in the transgenic plants under these treatments suggested that the transgenes were functionally expressed. Compared to transgenic plants, higher amounts of ROS were generated in the leaves of control plants exposed to abiotic stresses, resulting in increased thiobarbituric acid reactive substances (TBARS), ion leakage, and chlorophyll degradation. These parameters were significantly lower in transgenic plants. Enzyme activity assays and native polyacrylamide gel electrophoresis (PAGE) showed that total SOD and APX were highly active in transgenic plants under the abiotic stresses examined. We conclude that one of the mechanisms of increased anti-oxidative defense in transgenic tall fescue plants is overexpression of the CuZnSOD and APX genes, which are utilized in scavenging ROS and thus provide improved tolerance to abiotic stresses. PMID:17360071

Lee, Sang-Hoon; Ahsan, Nagib; Lee, Ki-Won; Kim, Do-Hyun; Lee, Dong-Gi; Kwak, Sang-Soo; Kwon, Suk-Yoon; Kim, Tae-Hwan; Lee, Byung-Hyun

2007-12-01

419

Chlorine activation within urban or power plant plumes: Vertically resolved ClNO2 and Cl2 measurements from a tall tower in a polluted continental setting  

NASA Astrophysics Data System (ADS)

chloride (ClNO2) is a chlorine atom source and reactive nitrogen reservoir formed during the night by heterogeneous reactions of dinitrogen pentoxide on chloride-containing aerosol particles. The main factors that influence ClNO2 production include nitrogen oxides, ozone, aerosol surface area, soluble chloride, and ambient relative humidity. Regions with strong anthropogenic activity therefore have large ClNO2 formation potential even inland of coastal regions due to transport or local emissions of soluble chloride. As part of the Nitrogen, Aerosol Composition, and Halogens on a Tall Tower field study, we report wintertime vertically resolved ClNO2 and molecular chlorine (Cl2) measurements taken on a 300 m tall tower located at NOAA's Boulder Atmospheric Observatory in Weld County, CO, during February and March of 2011. Gas and particle phase measurements aboard the tower carriage allowed for a detailed description of the chemical state of the nocturnal atmosphere as a function of height. These observations show significant vertical structure in ClNO2 and Cl2 mixing ratios that undergo dynamic changes over the course of a night. Using these measurements, we focus on two distinct combustion plume events where ClNO2 mixing ratios reached 600 and 1300 parts per trillion by volume, respectively, aloft of the nocturnal surface layer. We infer ClNO2 yields from N2O5-aerosol reactions using both observational constraints and box modeling. The derived yields in these plumes suggest efficient ClNO2 production compared to the campaign average, where in-plume yields range from 0.3 to 1; the campaign average yield in the boundary layer is 0.05 ± 0.15, with substantial night-to-night and within night variability similar to previous measurements in this region.

Riedel, Theran P.; Wagner, Nicholas L.; Dubé, William P.; Middlebrook, Ann M.; Young, Cora J.; Öztürk, Fatma; Bahreini, Roya; Vandenboer, Trevor C.; Wolfe, Daniel E.; Williams, Eric J.; Roberts, James M.; Brown, Steven S.; Thornton, Joel A.

2013-08-01

420

Inferences from CO2 and CH4 concentration profiles at the Zotino Tall Tower Observatory (ZOTTO) on regional summertime ecosystem fluxes  

NASA Astrophysics Data System (ADS)

The Siberian region is still sparsely covered by ecosystem observatories, which motivates the exploitation of existing data sets to gain spatially and temporally better-resolved carbon budgets. The Zotino Tall Tower Observatory (ZOTTO; 60°48' N, 89°21' E) observations of CO2 and CH4 mole fractions as well as meteorological parameters from six different heights up to 301 m allow for an additional estimate of surface-atmosphere fluxes of CO2 and CH4 for the middle Siberian region beginning 2009. The total carbon flux is calculated from the storage and the turbulent flux component. The gradients between the different tower levels determine the storage flux component, which dominates the regional fluxes, especially during nighttime. As a correction term, the turbulent flux component was estimated by the modified Bowen ratio method based on the sensible heat flux measurements at the top of the tower. The obtained average nighttime fluxes (23:00 to 04:00 local time) are 2.7 ± 1.1 ?mol (m2 s)-1 for CO2 and 5.6 ± 4.5 nmol (m2 s)-1 for CH4 during the summer months June-September in 2009 and 2011. During the day, the method is limited due to numeric instabilities because of vanishing vertical gradients; however, the derived CO2 fluxes exhibit reasonable diurnal shapes and magnitudes compared to the eddy covariance technique, which became available at the site in 2012. Therefore, the tall tower data facilitate the extension of the new eddy covariance flux data set backward in time. The diurnal signal of the CH4 flux is predominantly characterized by a strong morning transition, which is explained by local topographic effects.

Winderlich, J.; Gerbig, C.; Kolle, O.; Heimann, M.

2014-04-01

421

Inferences from CO2 and CH4 concentration profiles at the Zotino Tall Tower Observatory (ZOTTO) on local summer-time ecosystem fluxes  

NASA Astrophysics Data System (ADS)

The Siberian region is still sparsely covered by ecosystem observatories, which motivates to exploit existing datasets to gain spatially and temporally better-resolved carbon fluxes. The Zotino Tall Tower Observatory (ZOTTO, 60°48' N, 89°21' E) observations of CO2 and CH4 mole fractions as well as meteorological parameters from six different heights up to 301 m allow for an additional estimate of surface-atmosphere fluxes of CO2 and CH4 for the Middle-Siberian region since 2009. The total carbon flux is calculated from the storage and the turbulent flux component. The gradients between the different tower levels determine the storage flux component, which dominates the local fluxes, especially during night. As a correction term, the turbulent flux component was estimated by the modified Bowen ratio method based on the sensible heat flux measurements at the top of the tower. The gained average night time fluxes (23:00 to 04:00 local time) are 2.7 ± 1.1 ?mol (m2 s)-1 for CO2 and 5.6 ± 4.5 nmol (m2 s)-1 for CH4 during the summer months June-September in 2009 and 2011. During day, the method is limited due to numeric instabilities from vanishing vertical gradients; however, the derived CO2 fluxes exhibit reasonable diurnal shape and magnitude compared to the eddy covariance technique, which become available at the site in 2012. Therefore, the tall tower data facilitates the extension of the new eddy covariance flux dataset back in time. The diurnal signal of the CH4 flux is predominantly characterized by a strong morning transition, which is explained by local topographic effects.

Winderlich, J.; Gerbig, C.; Kolle, O.; Heimann, M.

2013-09-01

422

Development of CMC hydrogels loaded with silver nano-particles for medical applications.  

PubMed

Innovative CMC-based hydrogels with great potentials for usage in medical area were principally synthesized as per two strategies .The first involved reaction of epichlorohydrin in alkaline medium containing silver nitrate to yield silver nano-particles (AgNPs)-loaded CMC hydrogel. While CMC acted as stabilizing for AgNPs, trisodium citrate was added to the reaction medium to assist CMC in establishing reduction of Ag(+) to AgNPs. The second strategy entailed preparation of CMC hydrogel which assists the in situ preparation of AgNPs under the same conditions. In both strategies, factors affecting the characterization of AgNPs-loaded CMC hydrogels were studied. Analysis and characterization of the so obtained hydrogels were performed through monitoring swelling behavior, FTIR spectroscopy, SEM, EDX, UV-vis spectrophotometer and TEM. Antimicrobial activity of the hydrogels was examined and mechanisms involved in their synthesis were reported. PMID:23218313

Hebeish, Ali; Hashem, M; El-Hady, M M Abd; Sharaf, S

2013-01-30

423

Photocatalytical reduction of disulphide bonds in peptides on Ag-loaded nano-TiO2 for subsequent derivatization and determination.  

PubMed

We reported an alternative strategy to reduce disulphide bonds in peptides with Ag-nanoparticle loaded nano-TiO(2) (Ag/TiO(2)) under UV irradiation. The feasibility of this strategy was adequately demonstrated using the model peptides oxidized glutathione, vasopressin and insulin, which contain various disulphide bonds, as well as by its application to the determination of Cd-induced phytochelatins in Phaeodactylum tricornutum. PMID:21761048

Wang, Lijuan; Yan, Xiaowen; Xu, Chunlai; Xiao, Zhiliang; Yang, Limin; Zhang, Bo; Wang, Qiuquan

2011-09-21

424

Resonant frequency of gold/polycarbonate hybrid nano resonators fabricated on plastics via nano-transfer printing  

NASA Astrophysics Data System (ADS)

We report the fabrication of gold/polycarbonate (Au/PC) hybrid nano resonators on plastic substrates through a nano-transfer printing (nTP) technique, and the parametric studies of the resonant frequency of the resulting hybrid nano resonators. nTP is a nanofabrication technique that involves an assembly process by which a printable layer can be transferred from a transfer substrate to a device substrate. In this article, we applied nTP to fabricate Au/PC hybrid nano resonators on a PC substrate. When an AC voltage is applied, the nano resonator can be mechanically excited when the AC frequency reaches the resonant frequency of the nano resonator. We then performed systematic parametric studies to identify the parameters that govern the resonant frequency of the nano resonators, using finite element method. The quantitative results for a wide range of materials and geometries offer vital guidance to design hybrid nano resonators with a tunable resonant frequency in a range of more than three orders of magnitude (e.g., 10 KHz-100 MHz). Such nano resonators could find their potential applications in nano electromechanical devices. Fabricating hybrid nano resonators via nTP further demonstrates nTP as a potential fabrication technique to enable a low-cost and scalable roll-to-roll printing process of nanodevices.

Dechaumphai, Edward; Zhang, Zhao; Siwak, Nathan P.; Ghodssi, Reza; Li, Teng

2011-12-01

425

Resonant frequency of gold/polycarbonate hybrid nano resonators fabricated on plastics via nano-transfer printing  

PubMed Central

We report the fabrication of gold/polycarbonate (Au/PC) hybrid nano resonators on plastic substrates through a nano-transfer printing (nTP) technique, and the parametric studies of the resonant frequency of the resulting hybrid nano resonators. nTP is a nanofabrication technique that involves an assembly process by which a printable layer can be transferred from a transfer substrate to a device substrate. In this article, we applied nTP to fabricate Au/PC hybrid nano resonators on a PC substrate. When an AC voltage is applied, the nano resonator can be mechanically excited when the AC frequency reaches the resonant frequency of the nano resonator. We then performed systematic parametric studies to identify the parameters that govern the resonant frequency of the nano resonators, using finite element method. The quantitative results for a wide range of materials and geometries offer vital guidance to design hybrid nano resonators with a tunable resonant frequency in a range of more than three orders of magnitude (e.g., 10 KHz-100 MHz). Such nano resonators could find their potential applications in nano electromechanical devices. Fabricating hybrid nano resonators via nTP further demonstrates nTP as a potential fabrication technique to enable a low-cost and scalable roll-to-roll printing process of nanodevices.

2011-01-01

426

Chemical Interactions between Nano-ZnO and Nano-TiO2 in a Natural Aqueous Medium.  

PubMed

The use of diverse engineered nanomaterials (ENMs) potentially leads to the release of multiple ENMs into the environment. However, previous efforts to understand the behavior and the risks associated with ENMs have focused on only one material at a time. In this study, the chemical interactions between two of the most highly used ENMs, nano-TiO2, and nano-ZnO, were examined in a natural water matrix. The fate of nano-ZnO in Lake Michigan water was investigated in the presence of nano-TiO2. Our experiments demonstrate that the combined effects of ZnO dissolution and Zn adsorption onto nano-TiO2 control the concentration of dissolved zinc. X-ray absorption spectroscopy was used to determine the speciation of Zn in the particulate fraction. The spectra show that Zn partitions between nano-ZnO and Zn(2+) adsorbed on nano-TiO2. A simple kinetic model is presented to explain the experimental data. It integrates the processes of nano-ZnO dissolution with Zn adsorption onto nano-TiO2 and successfully predicts dissolved Zn concentration in solution. Overall, our results suggest that the fate and toxicity potential of soluble ENMs, such as nano-ZnO, are likely to be influenced by the presence of other stable ENMs, such as nano-TiO2. PMID:24918623

Tong, Tiezheng; Fang, Kaiqi; Thomas, Sara A; Kelly, John J; Gray, Kimberly A; Gaillard, Jean-François

2014-07-15

427

Implementation strategy  

NASA Technical Reports Server (NTRS)

Meeting the identified needs of Earth science requires approaching EOS as an information system and not simply as one or more satellites with instruments. Six elements of strategy are outlined as follows: implementation of the individual discipline missions as currently planned; use of sustained observational capabilities offered by operational satellites without waiting for the launch of new mission; put first priority on the data system; deploy an Advanced Data Collection and Location System; put a substantial new observing capability in a low Earth orbit in such a way as to provide for sustained measurements; and group instruments to exploit their capabilities for synergism; maximize the scientific utility of the mission; and minimize the costs of implementation where possible.

1983-01-01

428

Gold nano-wires and nano-layers at laser-induced nano-ripples on PET  

Microsoft Academic Search

Gold nano-layers were deposited onto laser irradiated polyethyleneterephthalate (PET) surfaces. For irradiation, we used the linearly polarized light of a pulsed 248nm KrF and 157nm F2 laser, respectively. In a certain range of irradiation parameters, the irradiation resulted in the formation of coherent ripples patterns with a lateral periodicity in the order of the wavelength of the laser light and

J. Siegel; P. Slepicka; J. Heitz; Z. Kolská; P. Sajdl; V. Švor?ík

2010-01-01

429

Bioinspired micro/nano fabrication on dental implant-bone interface  

NASA Astrophysics Data System (ADS)

Pioneering research suggests fabricating a biomimetic interface with multiscaled surfacial architecture can greatly improve biomaterials' function and property. According to this inspiration, we chiefly single out and analyze the natural hierarchical micro/nano structure in rat's alveolar bone. Then, a combined hierarchical structure, i.e. micro-pits interlaced self-assemble TiO2 nanotubes of several tens of nanometers on dental implant's surface is developed. The as-prepared surface showed that hundreds of self-assembled TiO2 nanotubes were tightly arrayed with a diameter range of 30-50 nm, similar to collagen fibers within rat's mandible (60-80 nm). Meanwhile, this hierarchical micro/nano surface can provide a larger surface energy and roughness, a preferable hydrophilicity, a more adaptive mechanical property and adhesion work, a better bioactivity and biocompatibity, a superior attachment and growth of osteoblasts as compared to the smooth and purely micro-treated counterparts. The results indicated that this bioinspired micro/nano fabrication on dental implant-bone interface can be potentially applied in the update of dental implant in patients' clinical therapy and provide a new strategy for fabricating other osteocompatible materials.

Wang, Feng; Shi, Liang; He, Wen-Xi; Han, Dong; Yan, Yan; Niu, Zhong-Ying; Shi, Sheng-Gen

2013-01-01

430

Synthesis of gold nano-wire and nano-dumbbell shaped colloids and AuC60 nano-clusters  

NASA Astrophysics Data System (ADS)

A technique for the fabrication of colloidal gold nano-wire and nano-dumbbell shaped particles using carbon nanotubes and rod shaped viruses as templates is described. The gold (Au) encapsulation process was accomplished by the precipitation of gold chloride from aqueous solutions. When this process was conducted in the presence of hydroxylated C60, small pieces of phase-separated composites of AuC60 appeared to have formed. These nano-clusters may turn out to be large noble metal analogs of the alkali metal fullerides with the smallest geometrically possible Au aggregate consisting of 55 gold atoms. The existence of noble metal fullerene composites has been previously theorized. The alkali metal fullerides are examples of phase separated solids and have exhibited superconductivity with temperatures as high 33K. The mechanism required for the binding energy between C60 and gold has been observed to exist between C60 and many of the mirror metals (Al, Ag, Au, Cu, Ni). This binding energy is a charge transfer from the metal Fermi level into the C60 LUMO. If this bonding energy, is greater than the metals coagulation energy an Au/C60 size terminated mechanism during the formation of the gold aggregates by the adhesion of C60 to the surface is energetically favorable.

Landon, Preston B.; Jarvis, Brandon C.; Gilleland, Cody L.; Renfro, Tim; Gutierrez, Jose; Synowczynski, Jennifer; Hirsch, Samuel G.; Glosser, Robert

2005-08-01

431

Toward High Performance Integrated Semiconductor Micro and Nano Lasers Enabled by Transparent Conducting Materials: from Thick Structure to Thin Film  

NASA Astrophysics Data System (ADS)

Integrated semiconductor lasers working at the wavelength around 1.3 microm and 1.55 microm are of great interest for the research of photonic integrated circuit (PIC) since they are the crucial components for optical communications and many other applications. To satisfy the requirement of the next generation optical communication and computing systems, integrated semiconductor lasers are expected to have high device performance like very low lasing threshold, high output powers, high speed and possibility of being integrated with electronics. This dissertation focuses on the design and realization of InP based high performance electrically pumped integrated semiconductor lasers. In the dissertation, we first design the tall structure based electrically pumped integrated micro-lasers. Those lasers are capable of giving >10 mW output power with a moderate low threshold current density (0.5--5 kA/cm 2). Besides, a new enhanced radiation loss based coupler design is demonstrated to realize single directional output for curvilinear cavities. Second, the thin film structure based integrated semiconductor laser designs are proposed. Both structures use the side conduction geometry to enable the electrical injection into the thin film laser cavity. The performance enhancement of the thin film structure based lasers is analyzed compared to the tall structure. Third, we investigate the TCO materials. CdO deposited by PLD and In 2O3 deposited by IAD are studied from aspects of their physical, optical and electrical properties. Those materials can give a wide range of tunability in their conductivity (1--5000 S/cm) and optical transparency (loss 200--5000 cm-1), which is of great interest in realizing novel nanophotonic devices. In addition, the electrical contact properties of those materials to InP are also studied. Experiment result shows that both CdO and In2O3 can achieve good ohmic contact to n-InP with contact resistance as low as 10-6O·cm 2. At last, we investigate some novel laser design based on the TCO materials and the thin film structure. The InP based coplanar electrode FP laser using In2O3 as the n-type cladding electrode is demonstrated. The design of the electrically pumped photonic crystal laser is also discussed. Initial fabrication result is given, showing potential of realizing those nano-lasers.

Ou, Fang

432

Teaching Strategy Using the Strategy Wheel  

Microsoft Academic Search

This paper presents the Strategy Wheel as an integrating framework for teaching strategic marketing. The Strategy Wheel combines concepts, perspectives and theories from marketing, innovation and strategic management into a single 8-step heuristic for teaching (and practising) strategy development. Based on the action-learning model from organizational behaviour, this approach emphasises 'learning by doing'. The Strategy Wheel was originally designed for

Chris Styles; Jules Goddard

2002-01-01

433

Nano-hydroxyapatite and Nano-titanium Dioxide Exhibit Different Subcellular Distribution and Apoptotic Profile in Human Oral Epithelium.  

PubMed

Nanomaterials (NMs) such as titanium dioxide (nano-TiO2) and hydroxyapatite (nano-HA) are widely used in food, personal care, and many household products. Due to their extensive usage, the risk of human exposure is increased and may trigger NMs specific biological outcomes as the NMs interface with the cells. However, the interaction of nano-TiO2 and nano-HA with cells, their uptake and subcellular distribution, and the cytotoxic effects are poorly understood. Herein, we characterized and examined the cellular internalization, inflammatory response and cytotoxic effects of nano-TiO2 and nano-HA using TR146 human oral buccal epithelial cells as an in vitro model. We showed both types of NMs were able to bind to the cellular membrane and passage into the cells in a dose dependent manner. Strikingly, both types of NMs exhibited distinct subcellular distribution profile with nano-HA displaying a higher preference to accumulate near the cell membrane compared to nano-TiO2. Exposure to both types of NMs caused an elevated reactive oxygen species (ROS) level and expression of inflammatory transcripts with increasing NMs concentration. Although cells treated with nano-HA induces minimal apoptosis, nano-TiO2 treated samples displayed approximately 28% early apoptosis after 24 h of NMs exposure. We further showed that nano-TiO2 mediated cell death is independent of the classical p53-Bax apoptosis pathway. Our findings provided insights into the potential cellular fates of human oral epithelial cells as they interface with industrial grade nano-HA and nano-TiO2. PMID:24734929

Tay, Chor Yong; Fang, Wanru; Setyawati, Magdiel Inggrid; Chia, Sing Ling; Tan, Kai Soo; Hong, Catherine Hsu Ling; Leong, David Tai

2014-05-14

434

A Compendium of Nano-/Microfabrication Facilities  

NSDL National Science Digital Library

This site offers a collection of nano/micro- fabrication facilities in the United States. The site's creator writes: "As part of the planning process for Harvard's new physical sciences building (NPSB), I thought I should familiarize myself with nano-/microfacilities that have been designed and built recently at other academic institutions. I have found that it has been most useful for me to record my browsings in html format and, for what it's worth, I herein share my findings with you. As a metric, I have included, where possible, an estimate of the cleanroom size of each facility (see table of comparisons). Unfortunately, comparisons are somewhat unreliable since it is not always clear whether gross or net square footages are being quoted and whether "gray" space is included in some tallies."

Jones, R. V.

2010-06-02

435

Magnetic resonances in nano-scale metamaterials  

NASA Astrophysics Data System (ADS)

We have designed, fabricated, and optically measured several different kinds of nano-scale metamaterials. We make use e-beam nano-lithography technology at LBNL's Center for X-Ray Optics for fabricating these structures on extremely thin SiN substrates so that they are close to free-standing. Optical properties were measured as a function of incidence angle and polarization. We directly observe a strong magnetic resonance consistent with a negative magnetic permeability in our samples at mid- and near-IR optical frequencies. We will discuss the results in comparison with detailed simulations, and will discuss the electric dipole or quadrupole resonances observed in the samples. Finally, we will report on our progress towards constructing a fully negative index of refraction meta-material.

Hao, Zhao; Liddle, Alex; Martin, Michael

2006-03-01

436

NanoHub: Online Simulation and More  

NSDL National Science Digital Library

NanoHUB is a web-based resource, published by the Network for Computational Nanotechnology (NCN), for research, education, and collaboration in nanotechnology, particularly nanoelectronics, nano-electromechanical systems (NEMS)/nanofluidics, and their application to nanobiosystems and devices. Resources include an extensive selection of online tools and simulations for a variety of nanotechnology topics. These appear as applets that run in a browser window, but are actually cluster-based items powered by architecture that lets users tap into national grid resources. The research page provides links to seminars, web meetings, user groups, and other collaborative resources. The educational page features introductory tutorials, curriculum materials, modules for self-paced web instruction, and other teaching materials (homework assignments, applets, lectures, and others) for students at all levels. There is also information for users who wish to contribute materials or otherwise support the organization.

2006-03-14

437

Antibacterial characteristics of heated scallop-shell nano-particles.  

PubMed

Heated scallop-shell (HSS) nano-particles, prepared using a wet grinding mill, and microparticles were examined for their antibacterial activity against vegetative bacterial cells and spores. The median diameters of the nano-particles and micro-particles were approximately 20 nm and 30 µm, respectively. The antibacterial activity of HSS against Escherichia coli increased with an increase in concentration, regardless of particle size; however, the antibacterial activity of the nano-particles was much higher than that of micro-particles. The sporicidal activity of the nano-particles was also much higher than that of micro-particles, with HSS nano-particles able to kill Bacillus subtilis spores. A reduction of more than three orders of magnitude for B. subtilis spores was confirmed following a 30 min treatment at 5 mg/ml and 60?, showing that the combination of HSS nano-particle treatment with mild heating was particularly effective for controlling bacterial spores. PMID:24975414

Watanabe, Takashi; Fujimoto, Riku; Sawai, Jun; Kikuchi, Mikio; Yahata, Shinya; Satoh, Susumu

2014-01-01

438