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1

Characterization of quasiparticle states at and beyond stability in ytterbium isotopes: Spectroscopy of 175Yb, 176Yb and 177Yb  

NASA Astrophysics Data System (ADS)

Excited states in 175Yb, 176Yb and 177Yb were populated via the bombardment of a 176Yb target with a 750 MeV 136Xe beam. Gamma-ray decays from these states were measured with the AFRODITE multi-detector spectrometer. The rotational band previously assigned to the ground state of 177Yb has been reassigned to the first-excited state of 175Yb. A new rotational band based on the ground state of 177Yb is presented, and the band based on the K? = 4- two-quasiparticle state in 176Yb has been identified. Also a candidate for the rotational band based on the K? = 8-, T1/2 = 11.4(3) s two-quasiparticle state in 176Yb has been found. Comparisons of gK values derived from in-band branching ratios are consistent with the ?9/2+[624] assignment to the ground state of 177Yb, the ?2{9/2+[624] ? 1/2-[510]} assignment to the K? = 4- state and with the ?2{9/2+[624] ? 7/2-[514]} assignment to the K? = 8- metastable excited state in 176Yb.

Ncapayi, N. J.; Mullins, S. M.; Benatar, M.; Gueorgueiva, E.; Lawrie, J. J.; Mabala, G. K.; Mukherjee, S.; Murray, S. H. T.; Mutshena, K. P.; Newman, R. T.; Sharpey-Schafer, J. F.; Smit, F. D.; Vymers, P.

2005-11-01

2

Ytterbium-doped fiber amplifiers  

Microsoft Academic Search

The ytterbium-doped fiber amplifier offers a number of attractive features, including a broad-gain bandwidth and a high efficiency, due in large part to its freedom from various competing processes seen in other rare-earth dopants. Here we discuss the main features that influence design and possible applications of ytterbium-doped fiber amplifiers

R. Paschotta; J. Nilsson; A. C. Tropper; D. C. Hanna

1997-01-01

3

Static dipole polarizability of ytterbium.  

PubMed

The static dipole polarizability of the ground state ytterbium atom is calculated using full and approximate relativistic ab initio methods. Our recommended polarizability of 143 au is consistent with experimental atomic spectral data. The corresponding van der Waals coefficient C6 of Yb2, derived using Padé approximants, is 2062 (200) au. PMID:17915845

Zhang, Peng; Dalgarno, Alexander

2007-12-13

4

Half life of 175Hf.  

PubMed

This work measured the half life of radioisotope (175)Hf, which was produced by neutron activation method at the ZF-300-II Intense Neutron Generator in Lanzhou University. The half life of (175)Hf, measured by ?-ray spectrometry using a well calibrated GEM-60P coaxial High Purity Germanium (HPGe) detector, has been found to be 70.65±0.19 days. The present result agrees with the literature data well, while the accuracy was improved. PMID:22871434

Fang, Kaihong; Wang, Dawei; Yang, Shaobo; Zhao, Jiangtao; Peng, Haibo; Wang, Qiang; Wang, Tieshan

2012-10-01

5

21 CFR 137.175 - Phosphated flour.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Phosphated flour. 137.175 Section 137.175 ...FOOD FOR HUMAN CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours and Related Products § 137.175...

2010-04-01

6

21 CFR 137.175 - Phosphated flour.  

Code of Federal Regulations, 2010 CFR

... 2009-04-01 false Phosphated flour. 137.175 Section 137.175 ...FOOD FOR HUMAN CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours and Related Products § 137.175...

2009-04-01

7

21 CFR 137.175 - Phosphated flour.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Phosphated flour. 137.175 Section 137.175 ...FOOD FOR HUMAN CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours and Related Products § 137.175...

2013-04-01

8

Hydrothermal synthesis of ytterbium silicate nanoparticles.  

PubMed

A simple, low-cost hydrothermal method was developed to synthesize 20-nm-diameter single-crystalline ytterbium silicate (Yb(2)Si(2)O(7) and Yb(2)SiO(5)) nanoparticles at 200 degrees C. This is nearly 1000 degrees C lower than that for the typical sol-gel route to ytterbium silicate powders. Obtained powders showed very low thermal conductivity, a suitable thermal expansion coefficient, and excellent thermal/structural stability, suggesting a potential application to environmental and thermal barrier coatings. Special focus was placed on assessing the hydrothermal reaction mechanism for particle formation. PMID:20085266

Chen, Hongfei; Gao, Yanfeng; Liu, Yun; Luo, Hongjie

2010-02-15

9

Optical properties of pure Ytterbium Alluminium perovskites  

NASA Astrophysics Data System (ADS)

We present the first report about growth and optical properties of pure Ytterbium Alluminium perovskites single crystals (YbAlO 3). The sample crystal structure was studied and assigned by means of Raman spectroscopy while the photoluminescence measurements from Yb 3+ charge-transfer state show a broad ultraviolet emission bands with nanosecond lifetimes at room temperature. Yb emissions are also studied as a function of temperature revealing an abrupt quenching in the 180-240 K range. The fast time decay and the high material density suggest Ytterbium Alluminium perovskites crystal as a good candidate for the development of fast scintillators for high energy physics applications.

Ricci, P. C.; Casu, A.; Chiriu, D.; Corpino, C.; Carbonaro, C. M.; Marceddu, M.; Salis, M.; Anedda, A.

2011-05-01

10

Beam combining of ytterbium fiber amplifiers (Invited)  

Microsoft Academic Search

Fiber lasers are well suited to scaling to high average power using beam-combining techniques. For coherent combining, optical phase-noise characterization of a ytterbium fiber amplifier is required to perform a critical evaluation of various approaches to coherent combining. For wavelength beam combining, we demonstrate good beam quality from the combination of three fiber amplifiers, and we discuss system scaling and

Steven J. Augst; Jinendra K. Ranka; T. Y. Fan; Antonio Sanchez

2007-01-01

11

Wavelength beam combining of ytterbium fiber lasers.  

PubMed

Wavelength beam combining of five ytterbium fiber lasers is demonstrated in a master-oscillator power-amplifier configuration at combined powers up to 6 W. The combined beam profile has an M2 value of 1.14, which is equal to that of an individual fiber. Beam steering in one dimension over 140 resolvable spots is also demonstrated. PMID:12659434

Augst, S J; Goyal, A K; Aggarwal, R L; Fan, T Y; Sanchez, A

2003-03-01

12

46 CFR 108.175 - Contiguous locations.  

Code of Federal Regulations, 2013 CFR

...Contiguous locations. 108.175 Section 108.175 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction and Arrangement Classified Locations...

2013-10-01

13

25 CFR 175.3 - Compliance.  

Code of Federal Regulations, 2011 CFR

...Section 175.3 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN ELECTRIC POWER UTILITIES General Provisions § 175.3 Compliance. All utility customers and the utilities are bound by the rule in...

2011-04-01

14

33 CFR 117.175 - Mokelumne River.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Mokelumne River. 117.175 Section 117.175 Navigation... California § 117.175 Mokelumne River. (a) The draw of the California...Transportation highway bridge, the Mokelumne River Bridge, mile 3.0, at East...

2011-07-01

15

33 CFR 117.175 - Mokelumne River.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Mokelumne River. 117.175 Section 117.175 Navigation... California § 117.175 Mokelumne River. (a) The draw of the California...Transportation highway bridge, the Mokelumne River Bridge, mile 3.0, at East...

2010-07-01

16

21 CFR 169.175 - Vanilla extract.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Vanilla extract. 169.175 Section 169.175 Food and Drugs...Dressings and Flavorings § 169.175 Vanilla extract. (a) Vanilla extract is the solution in aqueous ethyl alcohol of...

2010-04-01

17

21 CFR 169.175 - Vanilla extract.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Vanilla extract. 169.175 Section 169.175 Food and Drugs...Dressings and Flavorings § 169.175 Vanilla extract. (a) Vanilla extract is the solution in aqueous ethyl alcohol of...

2009-04-01

18

33 CFR 117.175 - Mokelumne River.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Mokelumne River. 117.175 Section 117.175 Navigation... California § 117.175 Mokelumne River. (a) The draw of the California...Transportation highway bridge, the Mokelumne River Bridge, mile 3.0, at East...

2013-07-01

19

Integrated ytterbium-Raman fiber amplifier.  

PubMed

An integrated ytterbium-Raman fiber amplifier architecture is proposed for power scaling of a Raman fiber laser. It is an ytterbium (Yb) fiber amplifier seeded with a double or multiple wavelength laser and followed by a passive Raman fiber. The bluest wavelength light gets amplified in the Yb fiber and the power is transferred to redder wavelengths in the following Raman fiber. A proof of principle experiment demonstrates a 300 W all-fiber linearly polarized single mode amplifier at 1120 nm with an optical efficiency of 70%, limited only by available pump power. The amplifier consists of 4 m of Yb-doped fiber and 20 m of germanium-doped fiber, and seeded with a laser emitting at 1070 and 1120 nm. The power evolution of the 1070 and 1120 nm light inside the amplifier is investigated, both numerically and experimentally. The possibility of power scaling to over kilowatt levels is discussed. PMID:24686642

Zhang, Lei; Jiang, Huawei; Cui, Shuzhen; Feng, Yan

2014-04-01

20

Compact, highly efficient ytterbium doped bismuthate glass waveguide laser.  

PubMed

Laser slope efficiencies close to the quantum defect limit and in excess of 78% have been obtained from an ultrafast laser inscribed buried channel waveguide fabricated in a ytterbium-doped bismuthate glass. The simultaneous achievement of low propagation losses and preservation of the fluorescence properties of ytterbium ions is the basis of the outstanding laser performance. PMID:22627539

Mary, R; Beecher, S J; Brown, G; Thomson, R R; Jaque, D; Ohara, S; Kar, A K

2012-05-15

21

Coherent Beam Combination of Two Polarization Maintaining Ytterbium Fibre Amplifiers  

Microsoft Academic Search

We investigate coherent beam combination of fibre laser beams by phase locking. Phase noise of a polarization maintaining ytterbium fibre amplifier is inspected with a fibre interferometer. In a feed back control loop, two fibre polarization maintaining ytterbium amplifiers are phase locked and coherent combined when the phase noise is properly controlled by a LiNO3 phase modulator.

Jing Hou; Rui Xiao; Zong-Fu Jiang; Xiang-Ai Cheng; Bai-Hong Shu; Jin-Bao Chen; Ze-Jin Liu

2005-01-01

22

33 CFR 175.135 - Existing equipment.  

Code of Federal Regulations, 2013 CFR

...equipment. Launchers manufactured before 1 January, 1981, which do not have approval numbers are acceptable for use with meteor or parachute signals listed in Table 175.130 under § 175.130 as long as they remain in serviceable condition....

2013-07-01

23

Fragmentation of One-Nucleon States in Ytterbium Isotopes.  

National Technical Information Service (NTIS)

Spectroscopic factors for one-nucleon transfer reactions of ytterbium isotopes were calculated in the framework of the superfluid nuclear model. The presence of structures in energy dependence of spectroscopic factors is shown which are determined by the ...

R. Duran L. A. Malov

1978-01-01

24

Experiments with Single Trapped Ytterbium Ions at JPL  

NASA Technical Reports Server (NTRS)

This paper presents viewgraphs of experiments performed with single trapped Ytterbium ions. The topics include: 1) Ytterbium ion level scheme; 2) Paul-Straubel rf trap and single ion image; 3) D5/2 state lifetime measurement; 4) D3/2 state lifetime measurement; 5) Trapped individual ions in an optical cavity; 6) Initial exploratory system: experimental goals; and 7) Future systems: trap-cavity integration II.

Yu, Nan; Maleki, Lute

2000-01-01

25

43 CFR 17.5 - Compliance information.  

Code of Federal Regulations, 2013 CFR

... NONDISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS OF THE DEPARTMENT OF THE INTERIOR Nondiscrimination on the Basis of Race, Color, or National Origin § 17.5 Compliance information. (a) Cooperation and assistance. The Secretary or...

2013-10-01

26

46 CFR 45.175 - Applicable routes.  

Code of Federal Regulations, 2013 CFR

...HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Unmanned River Barges on Lake Michigan Routes § 45.175 Applicable routes...following routes, including intermediate ports, on Lake Michigan, between Calumet Harbor, IL,...

2013-10-01

27

25 CFR 175.2 - Purpose.  

Code of Federal Regulations, 2011 CFR

...DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN ELECTRIC POWER UTILITIES General Provisions § 175.2 Purpose. The purpose of this part is to regulate the electric power utilities administered by the Bureau of...

2011-04-01

28

25 CFR 175.5 - Operations manual.  

Code of Federal Regulations, 2011 CFR

...DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN ELECTRIC POWER UTILITIES General Provisions § 175.5 Operations manual. ...action shall be published in local newspaper(s) of general circulation, posted at the utility...

2011-04-01

29

40 CFR 161.175 - Certified limits.  

Code of Federal Regulations, 2013 CFR

...PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR REGISTRATION OF ANTIMICROBIAL PESTICIDES Product Chemistry Data Requirements § 161.175 Certified limits. The applicant must propose certified limits for the...

2013-07-01

30

46 CFR 45.175 - Applicable routes.  

Code of Federal Regulations, 2010 CFR

...SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Unmanned River Barges on Lake Michigan Routes § 45.175 Applicable routes...subpart applies to the following routes on Lake Michigan, between Chicago (Calumet Harbor),...

2010-10-01

31

46 CFR 45.175 - Applicable routes.  

Code of Federal Regulations, 2012 CFR

...SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Unmanned River Barges on Lake Michigan Routes § 45.175 Applicable routes...routes, including intermediate ports, on Lake Michigan, between Calumet Harbor, IL, and—...

2012-10-01

32

46 CFR 45.175 - Applicable routes.  

Code of Federal Regulations, 2011 CFR

...SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Unmanned River Barges on Lake Michigan Routes § 45.175 Applicable routes...routes, including intermediate ports, on Lake Michigan, between Calumet Harbor, IL, and—...

2011-10-01

33

25 CFR 175.32 - Collections.  

Code of Federal Regulations, 2011 CFR

...and Collections § 175.32 Collections. The utility shall attempt collection on checks returned by the customer's bank due to insufficient funds or other cause. An administrative fee shall be charged for each collection action taken by the...

2011-04-01

34

Quantum Simulation of Magnetism with Ytterbium Ions  

NASA Astrophysics Data System (ADS)

An array of cold trapped ions has recently been identified as a promising physical implementation of a quantum simulator [1,2], thanks to the tunable long range couplings between ions and its advanced status on quantum computation applications. In particular, ions coupled by tightly bound transverse normal modes allows more efficient cooling and wide tunability of the effective spin-spin couplings. We will report our most recent simulation results of quantum spin Hamiltonians with few trapped ytterbium ions, coupled by transverse modes. We will also discuss on how this may be scaled up to a much larger number of spins with anharmonic traps and using multiple transverse modes. This work is supported by the DARPA OLE Program under ARO contract, IARPA under ARO contract, the NSF PIF Program, and the NSF Physics Frontier Center at JQI. [1] D. Porras and J. I. Cirac, Phys. Rev. Lett. 92, 207901 (2004) [2] A. Friedenauer et al., Nat. Phys. 4, 757 (2008)

Chang, Ming-Shien; Kim, Kihwan; Korenblit, Simcha; Islam, Kazi; Monroe, Christopher

2009-05-01

35

Ytterbium(III) triflate-catalyzed selective methanolysis of methoxyacetates: A new deprotective method  

SciTech Connect

The authors describe a novel method for the deprotection of the methoxyacetyl functionality under the catalytic influence of ytterbium(III) triflates. The ytterbium complex catalyzes the alcoholysis of methoxyacetyl under nonbasic conditions. The results for nine esters are reported.

Hanamoto, Takeshi; Sugimoto, Yuichi; Yokoyama, Yasuo; Inanaga, Junji [Inst. for Molecular Science, Okazaki (Japan)] [Inst. for Molecular Science, Okazaki (Japan); [Kyushu Univ., Fukuoka (Japan)

1996-06-28

36

33 CFR 175.130 - Visual distress signals accepted.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Visual distress signals accepted. 175.130 Section 175.130...SAFETY EQUIPMENT REQUIREMENTS Visual Distress Signals § 175.130 Visual distress signals accepted. (a) Any of the following...

2009-07-01

37

25 CFR 175.22 - Requirements for receiving electrical service.  

Code of Federal Regulations, 2011 CFR

... false Requirements for receiving electrical service. 175.22 Section 175...175.22 Requirements for receiving electrical service. In addition to the other...the customer, in order to receive electrical service, shall enter into a...

2011-04-01

38

ACTG 175: A Virology Substudy (on Diskette).  

National Technical Information Service (NTIS)

ACTG 175 was a randomized, double-blind, placebo-controlled trial to compare monotherapy with zidovudine or didanosine with combination therapy with zidovudine and didanosine or zidovudine and zalcitabine in HIV-1-infected subjects with CD4 cell counts be...

1998-01-01

39

21 CFR 172.175 - Sodium nitrite.  

Code of Federal Regulations, 2013 CFR

...HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD...172.175 Sodium nitrite. The food additive sodium nitrite may be safely used in...product. (b) To assure safe use of the additive, in addition to the other...

2013-04-01

40

175Hp contrarotating homopolar motor design report  

Microsoft Academic Search

A normally conducting contrarotating homopolar motor has been designed and constructed. The reaction torque, in the outer rotor, from the inner rotor is utilized to produce true contrarotation. The machine utilizes liquid cooled conductors, high performance liquid metal current collectors, and ferrous conductors in the active region. The basic machine output is 175 hp at + or - 1,200 rpm

Michael J. Cannell; John L. Drake; Richard A. McConnell; William R. Martino

1994-01-01

41

25 CFR 175.6 - Information collection.  

Code of Federal Regulations, 2011 CFR

...collection requirements contained in § 175.22 have been approved by the Office of Management and Budget under 44 U.S.C. 3501 et seq. and assigned clearance number 1076-0021. This information is being collected to provide electric power service to...

2011-04-01

42

Convenient preparation of ytterbium(III) chalcogenolate complexes by insertion of ytterbium into chalcogen-chalcogen bonds. Application in the ring-opening of epoxides  

Microsoft Academic Search

Convenient conditions are reported for the preparation of ytterbium(III) chalcogenolate complexes by insertion of ytterbium metal into the chalcogen–chalcogen bond of disulfides, diselenides, and ditellurides. The resulting complexes have been found to transfer arylsulfanyl, -selenanyl, and -telluranyl groups to epoxides in a facile ring-opening reaction. The ytterbium(III) chalcogenolate complexes appear to perform a dual role in both activating the epoxide,

Jennifer Dowsland; Fiona McKerlie; David J Procter

2000-01-01

43

All-fibre ytterbium laser tunable within 45 nm  

SciTech Connect

A tunable ytterbium-doped fibre laser is fabricated. The laser is tuned by using a tunable fibre Bragg grating (FBG) as a selecting intracavity element. The laser is tunable within 45 nm (from 1063 to 1108 nm) and emits {approx}6 W in the line of width {approx}0.15 nm, the output power and linewidth being virtually invariable within the tuning range. The method is proposed for synchronous tuning the highly reflecting and output FBGs, and a tunable ytterbium all-fibre laser is built. (lasers)

Abdullina, S R; Babin, S A; Vlasov, A A; Kablukov, S I; Shelemba, I S [Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation); Kurkov, A S [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation)

2007-12-31

44

175Hp contrarotating homopolar motor design report  

NASA Astrophysics Data System (ADS)

A normally conducting contrarotating homopolar motor has been designed and constructed. The reaction torque, in the outer rotor, from the inner rotor is utilized to produce true contrarotation. The machine utilizes liquid cooled conductors, high performance liquid metal current collectors, and ferrous conductors in the active region. The basic machine output is 175 hp at + or - 1,200 rpm with an input of 4 volts and 35,000 amps.

Cannell, Michael J.; Drake, John L.; McConnell, Richard A.; Martino, William R.

1994-06-01

45

Gain analysis of Erbium and Ytterbium Doped Optical Fiber Amplifiers  

Microsoft Academic Search

In this study, importance of optical amplifiers which are used in optical communication systems is explained and gains of EDFA, Erbium Doped Fiber Amplifier, and YDFA, Ytterbium Doped Fiber Amplifier, which are among the most commonly used optical amplifiers today, are analysed based on their performance parameters. The effects of the power of input signal, the power of pump laser,

Tolga Kucukarslan; N. Ozlem Unverdi

2012-01-01

46

Toward IFE Oriented Laser Chains: Cryogenically Cooled Ytterbium Doped Materials  

NASA Astrophysics Data System (ADS)

With the aim to set up Inertial Fusion Energy (IFE) driver, we develop the properties of the Ytterbium doped materials and the problems met when designing such a system: essentially thermal management and ASE gain depletion. We after present the experimental results obtained using sesquioxide Yb3+ doped ceramics at cryogenic temperature. We also propose a solution for minimizing the ASE problem.

Bourdet, G.; Casagrande, O.; Cardinali, V.; Deguil-Robin, N.; Le Garrec, B.

2009-09-01

47

Transition probability studies in 175Au  

NASA Astrophysics Data System (ADS)

Transition probabilities have been measured between the low-lying yrast states in 175Au by employing the recoil distance Doppler-shift method combined with the selective recoil-decay tagging technique. Reduced transition probabilities and magnitudes of transition quadrupole moments have been extracted from measured lifetimes allowing dramatic changes in nuclear structure within a low excitation-energy range to probed. The transition quadrupole moment data are discussed in terms of available systematics as a function of atomic number and aligned angular momentum.

Grahn, T.; Watkins, H.; Joss, D. T.; Page, R. D.; Carroll, R. J.; Dewald, A.; Greenlees, P. T.; Hackstein, M.; Herzberg, R.-D.; Jakobsson, U.; Jones, P. M.; Julin, R.; Juutinen, S.; Ketelhut, S.; Köll, Th; Krücken, R.; Labiche, M.; Leino, M.; Lumley, N.; Maierbeck, P.; Nyman, M.; Nieminen, P.; O'Donnell, D.; Ollier, J.; Pakarinen, J.; Peura, P.; Pissulla, Th; Rahkila, P.; Revill, J. P.; Rother, W.; Ruotsalainen, P.; Rigby, S. V.; Sarén, J.; Sapple, P. J.; Scheck, M.; Scholey, C.; Simpson, J.; Sorri, J.; Uusitalo, J.; Venhart, M.

2013-03-01

48

7 CFR 1260.175 - Late-payment charge.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Late-payment charge. 1260.175 Section...DEPARTMENT OF AGRICULTURE BEEF PROMOTION AND RESEARCH Beef Promotion and Research Order Assessments § 1260.175 Late-payment charge. Any...

2010-01-01

49

7 CFR 1260.175 - Late-payment charge.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Late-payment charge. 1260.175 Section...DEPARTMENT OF AGRICULTURE BEEF PROMOTION AND RESEARCH Beef Promotion and Research Order Assessments § 1260.175 Late-payment charge. Any...

2009-01-01

50

25 CFR 175.4 - Authority of area director.  

Code of Federal Regulations, 2011 CFR

...Section 175.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN ELECTRIC POWER UTILITIES General Provisions § 175.4 Authority of area director. The Area Director may delegate authority under...

2011-04-01

51

Interaction of ytterbium trifluoride with zirconium in a NaF-ZrF 4 molten mixture  

Microsoft Academic Search

The interaction of ytterbium trifluoride with zirconium in a molten mixture of sodium and zirconium fluorides have been studied\\u000a by differential thermal analysis, X-ray diffraction, and electronic and IR spectroscopy. In the temperature range 440–640°C,\\u000a zirconium reduces YbF3 to ytterbium. The reaction products also contain low-valence zirconium and ytterbium compounds.

N. M. Kompanichenko; R. N. Savchuk; N. V. Faidyuk; A. A. Omel’chuk; V. F. Zinchenko; N. I. Buryak

2008-01-01

52

21 CFR 175.270 - Poly(vinyl fluoride) resins.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Poly(vinyl fluoride) resins. 175.270 Section 175.270 Food and Drugs...Coatings § 175.270 Poly(vinyl fluoride) resins. Poly(vinyl fluoride) resins identified in this section may be safely...

2010-01-01

53

21 CFR 175.270 - Poly(vinyl fluoride) resins.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Poly(vinyl fluoride) resins. 175.270 Section 175.270 Food and Drugs...Coatings § 175.270 Poly(vinyl fluoride) resins. Poly(vinyl fluoride) resins identified in this section may be safely...

2012-04-01

54

21 CFR 175.270 - Poly(vinyl fluoride) resins.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Poly(vinyl fluoride) resins. 175.270 Section 175.270 Food and Drugs...Coatings § 175.270 Poly(vinyl fluoride) resins. Poly(vinyl fluoride) resins identified in this section may be safely...

2011-04-01

55

Spectroscopic and lasing properties of highly-doped Ytterbium-glasses  

Microsoft Academic Search

Ytterbium (Yb) doped glass is expected as next generation high-performance solid laser material. However, the laser glasses have a problem that the ions-doping-concentration is much lower than crystals. In this study, we make highly-doped Ytterbium-ions glasses (YbF3-BaF2-AlF3-GeO2, YbBAG), and succeeded laser oscillations of 20 mol.% Ytterbium-ions glass. The highly-doped Ytterbium-ions glasses are much suitable for short-fiber or waveguide lasers.

Kenta Sasaki; Hiroshi Furuta; Susumu Yonezawa; Shinichi Matsubara; Seiji Watanabe; Tatsuya Igarashi; Yutaka Kondo; Yoshinobu Sasatani; Hiroyuki Hitotsuya; Sakae Kawato

2011-01-01

56

Mode-Locked Ytterbium-Doped Fiber Lasers  

Microsoft Academic Search

In this article, we discuss recent advances in ultra-short pulse generation with ytterbium-doped fiber lasers. We discuss the fundamental properties and technical challenges of mode-locked single-mode fiber lasers operating in the 1-mum range, and the methods to achieve high peak-powers. We demonstrate a high-power passively mode-locked fiber laser based on a photonic crystal fiber featuring large-mode-core and short absorption length

Clovis Chédot; Caroline Lecaplain; Said Idlahcen; Gilles Martel; Ammar Hideur

2008-01-01

57

Dynamics of high-power erbium-ytterbium fiber amplifiers  

Microsoft Academic Search

Dynamic regimes of high-peak-power erbium-ytterbium (Er3+-Yb3+) codoped fiber amplifiers are analyzed for nanosecond-to-microsecond pulses. High-energy pulse generation requires a large-core fiber amplifier to increase energy storage and the threshold of nonlinear effects. A numerical model of large-core Er3+-Yb3+ fiber amplifiers is described. Dynamics of peak powers, amplified spontaneous emission, and population inversion are presented. Influence of radial dependence and reflections

Guillaume Canat; Jean-Claude Mollier; Jean-Pierre Bouzinac; Glenn M. Williams; Brian Cole; Lew Goldberg; Yves Jaouën; Gabor Kulcsar

2005-01-01

58

Pulsing dynamics in Ytterbium based chirped-pulse oscillators.  

PubMed

The properties of passively mode-locked laser oscillators based on Ytterbium doped gain media are studied theoretically along with experimental data. Based on the chirped-pulse approach limitations due to excessive non-linearities are avoided, opening up new routes for energy scaling of mode-locked solid-state oscillators. Predictions about potential future pulse energies are made and possible experimental problems are discussed. PMID:18794966

Siegel, Martin; Palmer, Guido; Emons, Moritz; Schultze, Marcel; Ruehl, Axel; Morgner, Uwe

2008-09-15

59

A four-passed ytterbium-doped fiber amplifier  

Microsoft Academic Search

In this paper, a four-passed ytterbium-doped fiber amplifier (YDFA) is discussed. The gain and the pump and the signal light propagation characteristics of the four-passed YDFA are described. It is found that, while using a shorter length of the fiber, a four-passed fiber amplifier can realize the same output power as a single-pass fiber amplifier, and, for the same fiber

Liu Yan; Wang Chunyu; Lu Yutian

2007-01-01

60

High peak power Ytterbium doped diode pumped fiber amplifier system  

Microsoft Academic Search

We have developed a fiber laser system capable of producing over 100W of average power. We have achieved 1.5mJ\\/pulse\\/fiber resulting in peak powers in excess of 2MW with 0.6ns pulses and near diffraction limited beams. In another fiber, we have achieved over 0.5mJ\\/pulse with pulses of 700ps exceeding 500kW of peak power in polarization maintaining Ytterbium doped fiber. In both

P. Madasamy; F. Kimpel; W. Torruellas

2007-01-01

61

Pulsed ytterbium-doped all fiber amplifier near 1mum  

Microsoft Academic Search

An all-fiber master oscillator power amplifier (MOPA) structured pulsed ytterbium (Yb)-doped fiber amplifier is reported in this paper. This amplifier utilizes a single seed diode, which is current-driven to generate optical pulses. The pulses repetition rate is tunable by changing the driven signal repetition rate. The seed pulses are then amplified in a series of Yb-doped fiber amplifiers (YDFAs). The

Cuiyun Zhou; Xia Hou; Song-Tao Du; Yuan Liu; Wei-Biao Chen

2011-01-01

62

Allelic Dimorphism of the Plasmodium falciparum Eryth- rocyte Binding Antigen175 (EBA175) Gene in the South east of Iran  

Microsoft Academic Search

Background: The erythrocyte binding antigen 175 kDa (EBA-175) gene is located on chromosome 7. It encodes protein that binds to specific receptor glycophorin A on the erythrocyte surface during inva- sion. It has a dimorphic nature (FCR3 and CAMP). This study was designed to determine the distribu- tion of EBA-175 alleles of Plasmodium falciparum in the southeast of Iran Methods:

A Heidari; H Keshavarz; S Dittrich; T Jelinek

2009-01-01

63

Luminescence and photoinduced absorption in ytterbium-doped optical fibres  

SciTech Connect

Photochemical reactions induced in the glass network of an ytterbium-doped fibre core by IR laser pumping and UV irradiation have been investigated by analysing absorption and luminescence spectra. We have performed comparative studies of the photoinduced absorption and luminescence spectra of fibre preforms differing in core glass composition: Al{sub 2}O{sub 3} : SiO{sub 2}, Al{sub 2}O{sub 3} : Yb{sub 2}O{sub 3} : SiO{sub 2}, and P{sub 2}O{sub 5} : Yb{sub 2}O{sub 3} : SiO{sub 2}. The UV absorption spectra of unirradiated preform core samples show strong bands peaking at 5.1 and 6.5 eV, whose excitation plays a key role in photoinduced colour centre generation in the glass network. 'Direct' UV excitation of the 5.1- and 6.5-eV absorption bands at 244 and 193 nm leads to the reduction of some of the Yb{sup 3+} ions to Yb{sup 2+}. The photodarkening of ytterbium-doped fibres by IR pumping is shown to result from oxygen hole centre generation. A phenomenological model is proposed for the IR-pumping-induced photodarkening of ytterbium-doped fibres. The model predicts that colour centre generation in the core glass network and the associated absorption in the visible range result from a cooperative effect involving simultaneous excitation of a cluster composed of several closely spaced Yb{sup 3+} ions.

Rybaltovsky, A A; Aleshkina, S S; Likhachev, M E; Bubnov, M M; Umnikov, A A; Yashkov, M V; Gur'yanov, Aleksei N; Dianov, Evgenii M

2011-12-31

64

Vaporization reactions in the ytterbium–fluorine system  

Microsoft Academic Search

The vaporization and sublimation reactions for the ytterbium fluoride system have been investigated by mass loss, x-ray powder diffraction, elemental analysis, and mass spectrometry. When YbF2.00 is heated in vacuum, it decomposes to give a metal rich vapor and a metal deficient residue until the composition YbF2.40(4) is reached. The following equilibrium reactions were established: YbF2.40(s,l) = (0.60)YbF2(g) + (0.40)YbF3(g),

Robert M. Biefeld; Harry A. Eick

1975-01-01

65

Vaporization reactions in the ytterbium-fluorine system  

Microsoft Academic Search

The vaporization and sublimation reactions for the ytterbium fluoride system have been investigated by mass loss, x-ray powder diffraction, elemental analysis, and mass spectrometry. When YbF2.00 is heated in vacuum, it decomposes to give a metal rich vapor and a metal deficient residue until the composition YbF2.40(4) is reached. The following equilibrium reactions were established: YbF2.40(s,l) = (0.60)YbF2(g) + (0.40)YbF3(g),

Robert M. Biefeld; Harry A. Eick

1975-01-01

66

A four-passed ytterbium-doped fiber amplifier  

NASA Astrophysics Data System (ADS)

In this paper, a four-passed ytterbium-doped fiber amplifier (YDFA) is discussed. The gain and the pump and the signal light propagation characteristics of the four-passed YDFA are described. It is found that, while using a shorter length of the fiber, a four-passed fiber amplifier can realize the same output power as a single-pass fiber amplifier, and, for the same fiber lengths, a four-passed fiber amplifier offers a significantly higher power than its single-pass counterpart.

Yan, Liu; Chunyu, Wang; Yutian, Lu

2007-09-01

67

Synopsis of Tests Demonstrating Improvements in 175mm Forgings.  

National Technical Information Service (NTIS)

Contributing to the improved quality of the 175mm gun tubes have been (a) elimination of chrome-plating of exceptionally high strength 175mm M113 material, (b) reduction of yield strength to effect significantly higher toughness, (c)improving quality of f...

E. N. Hegge

1969-01-01

68

45 CFR 17.5 - Context to be reflected.  

Code of Federal Regulations, 2013 CFR

...17.5 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION RELEASE OF ADVERSE INFORMATION TO NEWS MEDIA § 17.5 Context to be reflected. The authority for and the character of the information shall be made clear,...

2013-10-01

69

Biochemical Analysis of the Plasmodium falciparum Erythrocyte-binding Antigen-175 (EBA175)-Glycophorin-A Interaction  

PubMed Central

PfEBA175 has an important role in the invasion of human erythrocytes by Plasmodium falciparum and is therefore considered a high priority blood-stage malaria vaccine candidate. PfEBA175 mediates adhesion to erythrocytes through binding of the Duffy-binding-like (DBL) domains in its extracellular domain to Neu5Ac?2–3Gal displayed on the O-linked glycans of glycophorin-A (GYPA). Because of the difficulties in expressing active full-length (FL) P. falciparum proteins in a recombinant form, previous analyses of the PfEBA175-GYPA interaction have largely focused on the DBL domains alone, and therefore they have not been performed in the context of the native protein sequence. Here, we express the entire ectodomain of PfEBA175 (PfEBA175 FL) in soluble form, allowing us to compare the biochemical and immunological properties with a fragment containing only the tandem DBL domains (“region II,” PfEBA175 RII). Recombinant PfEBA175 FL bound human erythrocytes in a trypsin and neuraminidase-sensitive manner and recognized Neu5Ac?2–3Gal-containing glycans, confirming its biochemical activity. A quantitative binding analysis showed that PfEBA175 FL interacted with native GYPA with a KD ?0.26 ?m and is capable of self-association. By comparison, the RII fragment alone bound GYPA with a lower affinity demonstrating that regions outside of the DBL domains are important for interactions with GYPA; antibodies directed to these other regions also contributed to the inhibition of parasite invasion. These data demonstrate the importance of PfEBA175 regions other than the DBL domains in the interaction with GYPA and merit their inclusion in an EBA175-based vaccine.

Wanaguru, Madushi; Crosnier, Cecile; Johnson, Steven; Rayner, Julian C.; Wright, Gavin J.

2013-01-01

70

Magnetic susceptibility of semiconducting ReSi 1.75  

NASA Astrophysics Data System (ADS)

We measured the magnetic susceptibility of a single crystal of semiconducting ReSi 1.75 with the magnetic field aligned along the three main crystallographic directions. The susceptibility of ReSi 1.75 is strongly diamagnetic and anisotropic. Below 40 K, ? increases with decreasing temperature. We discuss the different contributions to the susceptibility of ReSi 1.75 and we explain the low temperature behaviour of ? in analogy to the behaviour of a doped semiconductor near the metal-insulator transition

Laborde, O.; Sulpice, A.; Gottlieb, U.; Madar, R.

1996-02-01

71

[Hygienic regulation of yttrium, terbium, ytterbium and lutetium fluorides in the air of the workplace].  

PubMed

The study (experiments on animals and on culture of rats' peritoneal macrophages) covered fluorides of rare-earth metals (REM) assigned to yttrium group--yttrium, terbium, ytterbium, lutetium. Fluorides of REM have low toxicity and cumulativity, induce no local irritation of skin and eyes. Fluorides of yttrium, terbium and lutetium, if administered into stomach, result in specific intoxication (fluorosis). Fluoride of ytterbium did not cause such intoxication. According to short-term tests of cytotoxicity, the foreseeable fibrogenic danger for ytterbium fluoride is moderate, for fluorides of yttrium, terbium and lutetium is mild. The authors recommend to control the level of yttrium, terbium and lutetium fluorides in the air of workplace through the MACs for the fluorides at 2.5 mg/cu m (maximal single concentration) and 0.5 mg/cu m (average shift concentration), the level of ytterbium fluoride as moderate fibrogenic dust at 6 mg/cu m. PMID:7881860

Neizvestnova, E M; Grekhova, T D; Privalova, L I; Babakova, O M; Konovalova, N E; Petelina, E V

1994-01-01

72

Novel design of M-profile ytterbium doped fibers for high power fiber lasers  

Microsoft Academic Search

A novel design of M-Profile Ytterbium doped Fibers (YDFs) for high power fiber Lasers was given. The output power was two times higher than that in standard double-cladding fiber under the same threshold of damage.

Jian Li; Xiang-qiao Mao; Lin Wang; Jian Peng; Li-song Liu; Huai Wei; Yong-jun Fu; Ting-gang Ning; Shui-sheng Jian

2007-01-01

73

Enantioselective synthesis of 3-hydroxy oxindoles by ytterbium-catalysed decarboxylative addition of ?-ketoacids to isatins.  

PubMed

A ytterbium(III)-indapybox catalysed enantioselective decarboxylative addition reaction of ?-ketoacids to isatins is described. The biologically important 3-hydroxy oxindoles were obtained in high yields and excellent enantioselectivities. PMID:23979548

Duan, Zhiqiang; Han, Jianlin; Qian, Ping; Zhang, Zirui; Wang, Yi; Pan, Yi

2013-10-14

74

Facility No. 175, interior detail showing rolling doors, trusses, and ...  

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

Facility No. 175, interior detail showing rolling doors, trusses, and angled monitor roof - U.S. Naval Base, Pearl Harbor, Landplane Hangar Type, Wasp Boulevard and Gambier Bay Street, Pearl City, Honolulu County, HI

75

Facility No. 175, interior of office space on second floor ...  

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

Facility No. 175, interior of office space on second floor of northwest side - U.S. Naval Base, Pearl Harbor, Landplane Hangar Type, Wasp Boulevard and Gambier Bay Street, Pearl City, Honolulu County, HI

76

Facility No. 175, interior overview from secondfloor corridor on northwest ...  

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

Facility No. 175, interior overview from second-floor corridor on northwest side - U.S. Naval Base, Pearl Harbor, Landplane Hangar Type, Wasp Boulevard and Gambier Bay Street, Pearl City, Honolulu County, HI

77

Facility No. 175, elevation of southeast side from the airfield, ...  

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

Facility No. 175, elevation of southeast side from the airfield, corner of Facility No. 176 is to the left - U.S. Naval Base, Pearl Harbor, Landplane Hangar Type, Wasp Boulevard and Gambier Bay Street, Pearl City, Honolulu County, HI

78

Facility No. 175, exterior oblique view of northeast and northwest ...  

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

Facility No. 175, exterior oblique view of northeast and northwest sides, corner of Facility No. 176 is in background - U.S. Naval Base, Pearl Harbor, Landplane Hangar Type, Wasp Boulevard and Gambier Bay Street, Pearl City, Honolulu County, HI

79

14 CFR 23.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2010 CFR

...CATEGORY AIRPLANES Flight Stability § 23.175 Demonstration of static longitudinal stability. Static longitudinal stability must be shown as follows: ...force curve must have a stable slope at speeds between 85 and 115...

2010-01-01

80

7 CFR 4280.174-4280.175 - [Reserved  

...BUSINESS-COOPERATIVE SERVICE AND RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE LOANS AND GRANTS Rural Energy for America Program General Renewable Energy System Feasibility Study Grants §§ 4280.174-4280.175...

2014-01-01

81

25 CFR 175.11 - Procedures for setting service fees.  

Code of Federal Regulations, 2011 CFR

...INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN ELECTRIC POWER UTILITIES Service Fees, Electric Power Rates and Revenues § 175.11 Procedures for setting service fees. The Area Director shall establish, and amend as...

2011-04-01

82

23. 175 TON CAPACITY CHARGING LADLE ON THE CHARGING AISLE ...  

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

23. 175 TON CAPACITY CHARGING LADLE ON THE CHARGING AISLE OF THE BOP SHOP LOOKING SOUTH. HISTORIAN FOR SCALE. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

83

21. 175 TON CAPACITY TEEMING LADLES ON THE NEAR WESTERN ...  

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

21. 175 TON CAPACITY TEEMING LADLES ON THE NEAR WESTERN TEEMING AISLE OF THE BOP SHOP LOOKING SOUTHEAST. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

84

20. 175 TON CAPACITY TEEMING LADLES ON THE NEAR WESTERN ...  

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

20. 175 TON CAPACITY TEEMING LADLES ON THE NEAR WESTERN TEEMING AISLE OF THE BOP SHOP LOOKING SOUTHEAST. HISTORIAN FOR SCALE. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

85

View of 175 ton hoisthouse from northeast. Hoist operator's cab ...  

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

View of 175 ton hoist-house from northeast. Hoist operator's cab is in foreground center. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

86

Interior view of 175 ton hoist house looking at the ...  

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

Interior view of 175 ton hoist house looking at the exterior casing for the wire rope spools. - Marshall Space Flight Center, Saturn V Dynamic Test Facility, East Test Area, Huntsville, Madison County, AL

87

40 CFR 46.175 - Terms and conditions.  

Code of Federal Regulations, 2013 CFR

...AND OTHER FEDERAL ASSISTANCE FELLOWSHIPS Award § 46.175 Terms and... (a) If EPA awards you a fellowship on the basis of a nomination...government employer, by accepting the fellowship agreement you agree to...

2013-07-01

88

40 CFR 60.175 - Monitoring of operations.  

Code of Federal Regulations, 2013 CFR

...PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.175 Monitoring of operations. (a) The owner or operator of any primary zinc smelter subject to the provisions of this subpart shall install and...

2013-07-01

89

Numerical analysis of injection-seeded ytterbium-doped fiber laser  

NASA Astrophysics Data System (ADS)

In this paper, the gain characteristics of injection-seeded ytterbium-doped fiber laser were demonstrated. Comparing with the conventional single-pass and double-pass fiber amplifier, the injection-seeded ytterbium-doped fiber laser has many advantages: such as high gain or output power, simple structure. The amplified spontaneous emission (ASE) of this fiber laser also was discussed in detail.

Liu, Y.; Lan, L. L.; Ren, S. F.; Zeng, S. G.; Li, J.

2012-10-01

90

Structural and Electronic Transitions in Ytterbium Metal to 202 GPa  

NASA Astrophysics Data System (ADS)

Ytterbium (Yb), a member of the rare earth group metals with a filled f shell and a divalent electronic character, has been studied under static high pressures in a diamond anvil cell to 202 GPa. We report a new transformation from a face-centered-cubic structure to a hexagonal phase with 3 atoms/cell (space group P3121 referred to as hP3) at 98+/-5 GPa. This hP3 phase is similar to that observed in trivalent neodymium and samarium at pressures near 40 GPa. Our high pressure study thus clearly demonstrates that Yb is no longer an ``irregular'' member of the rare earth metals, and divalent to trivalent electronic transition is completed at megabar pressures.

Chesnut, Gary N.; Vohra, Yogesh K.

1999-02-01

91

Structural and Electronic Transitions in Ytterbium Metal to 202 GPa  

SciTech Connect

Ytterbium (Yb), a member of the rare earth group metals with a filled f shell and a divalent electronic character, has been studied under static high pressures in a diamond anvil cell to 202thinspthinspGPa. We report a new transformation from a face-centered-cubic structure to a hexagonal phase with 3thinspthinspatoms/cell (space group P3{sub 1}21 referred to as hP3 ) at 98{plus_minus}5 GPa . This hP3 phase is similar to that observed in trivalent neodymium and samarium at pressures near 40thinspthinspGPa. Our high pressure study thus clearly demonstrates that Yb is no longer an {open_quotes}irregular{close_quotes} member of the rare earth metals, and divalent to trivalent electronic transition is completed at megabar pressures. {copyright} {ital 1999} {ital The American Physical Society}

Chesnut, G.N.; Vohra, Y.K. [Department of Physics, University of Alabama at Birmingham (UAB), Birmingham, Alabama 35294-1170 (United States)] [Department of Physics, University of Alabama at Birmingham (UAB), Birmingham, Alabama 35294-1170 (United States)

1999-02-01

92

High gain ytterbium doped Ge pedestal large pitch fiber  

NASA Astrophysics Data System (ADS)

Large mode area rod-type fibers have enabled amplification of ultra-short pulses to mJ pulse energy and MW peak powers. For very large mode field areas, fibers have to be designed as rigid rods with typical fiber lengths of around 1 m for efficient operation. A shorter fiber length can be desirable to reduce the packaging size of commercial systems and to decrease the impact of parasitic nonlinear effects for peakpower scaling. The fiber design presented here is based on a modified large-pitch fiber with an effectively higher ytterbium concentration in the fiber core. To achieve index matching the cladding index needs to be changed. In this contribution we propose to co-dope the passive host material with germanium to match both indices and to obtain a higher Yb-concentration within the active core. Compared to standard LPF, where the core index is reduced by co-doping the core with Flourine, the ytterbium doping concentration of this novel germanium-pedestal LPF is doubled. A detailed numerical and experimental investigation shows that with short fiber lengths <40cm is feasible to achieve output powers beyond 100W with 10W seed. Significantly higher gains, of nearly 30 dB, can be achieved for fiber lengths in the order of 60cm. A similar gain can be expected in a conventional LPF with 1.20 m length. In conclusion, we demonstrate a fiber design for significantly enhanced energy storage per fiber length and improved pump absorption. This concept will notably reduce the footprint of ultra-short fiber laser systems.

Gaida, Christian; Stutzki, Fabian; Jansen, Florian; Otto, Hans-Jürgen; Eidam, Tino; Jauregui, Cesar; Limpert, Jens; Tünnermann, Andreas

2014-03-01

93

Distribution of erythrocyte binding antigen 175 (EBA-175) gene dimorphic alleles in Plasmodium falciparum field isolates from Sudan  

PubMed Central

Background The Erythrocyte Binding Antigen (EBA) 175 has been considered as one of the most important Plasmodium falciparum (P. falciparum) merozoite ligands that mediate invasion of the erythrocytes through their sialated receptor: Glycophorin A (GPA). The effect of the EBA 175 dimorphic alleles (F and C) on the severity of the disease is not yet fully understood. Therefore this study was designed to assess the distribution of the divergent dimorphic alleles of P. falciparum EBA-175 (F and C) in three different geographical areas in Sudan and the possible association of this dimorphism with the severity of the disease. Methods A sum of 339 field isolates of P. falciparum obtained from patients in three different geographical areas in Sudan were screened for the dimorphic alleles (F, C) of the EBA-175 using nested PCR. Results The percentage of F, C, and mixed F/C alleles were; 41%, 51%, and 8% respectively. F and C alleles showed significantly different distributions in the various geographic areas (p?=?0.00). There was no significant association between malaria clinical manifestation and P. falciparum EBA-175 F and C alleles frequencies. Conclusions This study showed a significant differential distribution of F and C alleles in different geographical malaria endemic areas. No significant association was observed between F and C alleles and different malaria phenotypes.

2013-01-01

94

Facility No. 175, oblique view of southeast side and southwest ...  

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

Facility No. 175, oblique view of southeast side and southwest doors, corner of Facility No. 176 is on the left - U.S. Naval Base, Pearl Harbor, Landplane Hangar Type, Wasp Boulevard and Gambier Bay Street, Pearl City, Honolulu County, HI

95

Airfield setting of Facility Nos. 175 and 176, taken from ...  

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

Airfield setting of Facility Nos. 175 and 176, taken from north end of Ford Island Runway, with landplane hangars on the right - U.S. Naval Base, Pearl Harbor, Landplane Hangar Type, Wasp Boulevard and Gambier Bay Street, Pearl City, Honolulu County, HI

96

Facility No. 175, oblique view of southwest doors and northwest ...  

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

Facility No. 175, oblique view of southwest doors and northwest side, corner of Facility No. 176 is on the right - U.S. Naval Base, Pearl Harbor, Landplane Hangar Type, Wasp Boulevard and Gambier Bay Street, Pearl City, Honolulu County, HI

97

25 CFR 175.10 - Revenues collected from power operations.  

Code of Federal Regulations, 2011 CFR

...UTILITIES Service Fees, Electric Power Rates and Revenues § 175.10 Revenues collected...shall set service fees and electric power rates in accordance with the procedures in...required or permitted by law. (b) Rate and fee reviews. Rates and fees...

2011-04-01

98

Quasiparticle alignments and ?-decay fine structure of 175Pt  

NASA Astrophysics Data System (ADS)

Excited states and decay properties of 175Pt have been investigated using the 92Mo(86Sr,2pn) fusion-evaporation reaction. The JUROGAM I ?-ray spectrometer and the GREAT spectrometer were used in conjunction with the gas-filled recoil separator RITU for the measurement of the radiation at the target and focal plane positions, respectively. Two new band structures, assigned to be based on the I?=(7/2-) ground state in 175Pt, have been established and the known yrast band has been extended up to I?=(49/2+). Rotational properties of the excited states in 175Pt have been investigated within the cranked shell-model formalism. The low-frequency changes in the alignments of the positive- and negative-parity bands are interpreted as a sign of proton-pair excitations in the rotating core. Furthermore, the ?-decay measurements reveal a candidate for a fourth ?-decay branch in 175Pt, feeding a non-yrast state in 171Os.

Peura, P.; Scholey, C.; Joss, D. T.; Juutinen, S.; Julin, R.; Bäck, T.; Cederwall, B.; Greenlees, P. T.; Jakobsson, U.; Jones, P.; Judson, D. S.; Ketelhut, S.; Labiche, M.; Leino, M.; Nyman, M.; O'Donnell, D.; Page, R. D.; Rahkila, P.; Ruotsalainen, P.; Sandzelius, M.; Sapple, P. J.; Sarén, J.; Simpson, J.; Thomson, J.; Uusitalo, J.; Watkins, H. V.

2014-02-01

99

33 CFR 175.130 - Visual distress signals accepted.  

Code of Federal Regulations, 2013 CFR

...meet the day only requirement. (3) Pyrotechnics meeting the standards noted in Table...night requirements. Table 175.130âPyrotechnic Signal Devices Approval number under...Distress Signal for Boats, Red Aerial Pyrotechnic Flare Day and Night 2 3 1...

2013-07-01

100

Precision Atomic Masses of Calcium, Strontium and Ytterbium  

NASA Astrophysics Data System (ADS)

Currently the second most precise value for the fine structure constant is derived from ``photon-recoil'' measurements of h/M(Rb) combined with the Rydberg constant, atomic transition frequencies, and the atomic masses of the electron and rubidium. An improved photon-recoil value for alpha will enable the combination of theory and experiment for the g-factor of the electron, which produces the most precise value for alpha, to provide an improved test of QED. Besides the alkalis, isotopes of the alkaline-earths and ytterbium can make promising candidates for precise photon-recoil measurements of h/M(atom). In addition, the mass of 40Ca is required for obtaining the g-factor of hydrogen-like calcium from measurements of electron spin-flip and cyclotron frequencies of Ca19+, which would provide a test of bound-state QED theory. For these and other applications, we have now measured cyclotron frequency ratios of pairs of ions in a cryogenic Penning trap that should yield the atomic masses of 40Ca, 86,87,88Sr, and 170,171,172,173,174,176Yb to a precision of ˜0.2 ppb.

Myers, Edmund; Rana, Raman; Hoecker, Martin

2012-06-01

101

Simulating Quantum Spin Models with Trapped Ytterbium Ions^1  

NASA Astrophysics Data System (ADS)

Simulating large quantum many-body systems is practically impossible with classical computers, as it requires resources exponential in the system size. An array of cold trapped ions has recently been identified as a promising candidate for exploring many-body spin Hamiltonians. This is due to superb control of their quantum states and interactions, high-fidelity spin state detection of each and every ion, and very long coherence time. We will initially work with less than 10 ions, but will speculate on how this may be scaled up to larger numbers of spins. We will report the recent progress toward quantum simulations of Heisenberg-like spin Hamiltonians [1] with trapped Ytterbium ions in a linear Paul trap. [1] D. Porras and J. I. Cirac, Phys. Rev. Lett. 92, 207901 (2004) ^1This work is supported by the DARPA OLE Program under ARO Award W911NF-07-1-0576, IARPA under ARO contract W911NF-04-1-0234, and the NSF PIF Program under grant PHY-0601255.

Chang, M.-S.; Kim, K.; Korenblit, S.; Islam, K. R.; Sterk, J. D.; Chew, A.; Slusher, R.; Monroe, C.

2008-05-01

102

Soft-x-ray amplification at 50. 3 A in nickellike ytterbium  

SciTech Connect

Nickellike ions of ytterbium (Yb/sup 42+/) have been produced in long exploding foil plasmas. The plasmas were formed by short-pulse laser irradiation of thin foils of ytterbium with line-focused high-intensity 0.53-..mu..m light. Soft-x-ray line emissions at 50.26 and 56.09 A are identified as 4d--4p, J = 0--1 transitions in the nickellike ionization stage of ytterbium. The energy emitted in the line at 50.26 A along the axis of the plasma is observed to increase nonlinearly with plasma length, consistent with a small-signal gain of 1.2 +- 0.4 cm/sup -1/.

MacGowan, B.J.; Maxon, S.; Keane, C.J.; London, R.A.; Matthews, D.L.; Whelan, D.A.

1988-09-01

103

Strong UV absorption and visible luminescence in ytterbium-doped aluminosilicate glass under UV excitation.  

PubMed

A broad visible luminescence band and characteristic IR luminescence of Yb(3+) ions are observed under UV excitation in ytterbium-doped aluminosilicate glass. Samples made under both oxidizing and reducing conditions are analyzed. A strong charge-transfer absorption band in the UV range is observed for glass samples containing ytterbium. Additional absorption bands are observed for the sample made under reducing conditions, which are associated with f-d transitions of divalent ytterbium. The visible luminescence band is attributed to 5d-4f emission from Yb(2+) ions, and the IR luminescence is concluded to originate from a relaxed charge-transfer transition. The findings are important to explain induced optical losses (photodarkening) in high-power fiber lasers. PMID:18026305

Engholm, M; Norin, L; Aberg, D

2007-11-15

104

Lifetime measurements probing triple shape coexistence in 175Au  

NASA Astrophysics Data System (ADS)

Lifetimes of the low-lying excited states in the very neutron-deficient nucleus 175Au have been measured by the recoil-distance Doppler-shift method using ?-ray spectra obtained with the recoil-decay tagging technique. Transition quadrupole moments and reduced transition probabilities extracted for this odd-Z nucleus indicate the existence of three different shapes and the competition between collective and noncollective structures.

Watkins, H.; Joss, D. T.; Grahn, T.; Page, R. D.; Carroll, R. J.; Dewald, A.; Greenlees, P. T.; Hackstein, M.; Herzberg, R.-D.; Jakobsson, U.; Jones, P. M.; Julin, R.; Juutinen, S.; Ketelhut, S.; Kröll, T.; Krücken, R.; Labiche, M.; Leino, M.; Lumley, N.; Maierbeck, P.; Nyman, M.; Nieminen, P.; O'Donnell, D.; Ollier, J.; Pakarinen, J.; Peura, P.; Pissulla, T.; Rahkila, P.; Revill, J. P.; Rother, W.; Ruotsalainen, P.; Rigby, S. V.; Sarén, J.; Sapple, P. J.; Scheck, M.; Scholey, C.; Simpson, J.; Sorri, J.; Uusitalo, J.; Venhart, M.

2011-11-01

105

Role of ytterbium and ytterbium\\/cesium fluoride on the chemistry of poly(9,9-dioctylfluorene-co-benzothiadiazole) as investigated by photoemission spectroscopy  

Microsoft Academic Search

Since ytterbium (Yb) possesses a low work function of 2.6 eV and Yb fluoride generally has a high negative free energy of formation, it is conceivable to use Yb, either directly or parasitically, with a metal fluoride, as a cathode in organic light-emitting diodes (OLEDs). In this work, the electronic structure and chemistry at the interface of Yb\\/poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) were

M. K. Fung; S. W. Tong; S. L. Lai; S. N. Bao; C. S. Lee; W. W. Wu; M. Inbasekaran; J. J. O'Brien; S. Y. Liu; S. T. Lee

2003-01-01

106

High-quality laser cutting of stainless steel in inert gas atmosphere by ytterbium fibre and CO2 lasers  

NASA Astrophysics Data System (ADS)

Processes of cutting stainless steel by ytterbium fibre and CO2 lasers have been experimentally compared. The cut surface roughnesses for 3- and 5-mm-thick stainless steel sheets are determined. The absorption coefficient of laser radiation during cutting is measured. It is established that the power absorbed by metal during cutting by the CO2 laser exceeds that for the ytterbium laser (provided that the cutting speed remains the same). The fact that the maximum cutting speed of the CO2 laser is lower than that of the ytterbium fibre laser is explained.

Golyshev, A. A.; Malikov, A. G.; Orishich, A. M.; Shulyat'ev, V. B.

2014-03-01

107

Second harmonic generation of spectrally broadened femtosecond ytterbium laser radiation in a gas-filled capillary  

SciTech Connect

A 300-fs radiation pulse of an ytterbium laser with a wavelength of 1030 nm and energy of 150 {mu}J were converted to a 15-fs pulse with a wavelength of 515 nm by broadening the emission spectrum in a capillary filled with xenon and by generating the second harmonic in a KDP crystal. The energy efficiency of the conversion was 30 %.

Didenko, N V; Konyashchenko, Aleksandr V; Kostryukov, P V; Losev, Leonid L; Tenyakov, S Yu

2011-09-30

108

All-Normal-Dispersion Dissipative Soliton Ytterbium Fiber Laser Without Dispersion Compensation and Additional Filter  

Microsoft Academic Search

We report on the generation of mode-locked dissipative soliton pulse from an all- fiber ytterbium-doped fiber laser based on nonlinear polarization rotation without dispersion compensation or an additional filter. The formation of the dissipative soliton pulse is a self- consistent result of various effects in the laser cavity, including positive fiber dispersion, nonlinearity, cavity transmission, and gain saturation and narrowing

Zuxing Zhang; Guoxing Dai

2011-01-01

109

Thermal Characteristics of an Ytterbium-Doped Fiber Amplifier Operating at 1060 and 1080 nm  

Microsoft Academic Search

We experimentally analyze the temperature dependence of an ytterbium-doped fiber amplifier (YDFA) operating at 1060 and 1080 nm, investigating its spectroscopic characteristics and gain properties in the temperature range of 10 to 100 °C. Our measurement indicates that the change in the operating temperature can give rise to a significant effect on the YDFA performance, which also significantly depends on

Luis Alonso Vazquez-Zuniga; Seunghwan Chung; Yoonchan Jeong

2010-01-01

110

A High-Efficiency Ytterbium-Doped Fiber Amplifier Designed for Interplanetary Laser Communications  

Microsoft Academic Search

Design, performance, and environmental screening of flight prototype Ytterbium amplifiers designed for the Mars Laser Communications Demonstration are described. The high-reliability design delivered >8-W average power with low-duty-cycle PPM waveforms and >21% electrical-to-optical conversion efficiency.

Neal W. Spellmeyer; David O. Caplan; Bryan S. Robinson; David Sandberg; Mark L. Stevens; Matt M. Willis; Denis V. Gapontsev; Nikolai S. Platonov; Alexander Yusim

2007-01-01

111

Model of Temperature Dependence Shape of Ytterbium -doped Fiber Amplifier Operating at 915 nm Pumping Configuration  

Microsoft Academic Search

We numerically analyze the temperature dependence of an ytterbium-doped fiber amplifier (YDFA) operating at 915 nm, investigating its gain and Noise Figure properties variation with temperature. The temperature-dependent gain and noise figure variation with YDFA length are numerically obtained for the temperature range of +20 0 C to +70 0 C. The results show that good intrinsic output stability against

Abdel Hakeim; M. Husein; Fady I. EL-Nahal

2011-01-01

112

Experimental observation of vector solitons in a highly birefringent cavity of ytterbium-doped fiber laser.  

PubMed

We report on the first experimental observation of dark-bright and dark-dark vector solitons in a highly birefringent cavity of all-normal-dispersion ytterbium-doped fiber laser. With the usage of different length of polarization maintaining fibers in the cavity, totally four types of vector solitons with different features were observed. PMID:24104297

Yuan, Xiaozhi; Yang, Tong; Chen, Jiali; He, Xin; Huang, Huichang; Xu, Shanhui; Yang, Zhongmin

2013-10-01

113

Optical Absorption Spectrum and Optical Zeeman Effect in Triply Ionized Ytterbium-Doped Calcium Tungstate.  

National Technical Information Service (NTIS)

The absorption spectrum of 0.01- to 0.05-percent ytterbium-doped calcium tungstate at liquid helium temperature was measured. Some of the samples contained sodium for charge-compensation. The effect of Na-charge-compensation for Yb was similar to that for...

G. Jones

1966-01-01

114

Residual stresses and phase transformations in Ytterbium silicate environmental barrier coatings  

NASA Astrophysics Data System (ADS)

Due to their high melting temperature, low density, and good thermomechanical stability, silicon-based ceramics (SiC, Si3N4) are some of the most promising materials systems for high temperature structural applications in gas turbine engines. However, their silica surface layer reacts with water vapor contained in combustion environments. The resulting hydroxide layer volatilizes, leading to component recession. Environmental barrier coatings (EBCs) have been developed to shield the substrate from degradation. Next generation coatings for silicon-based ceramics based on ytterbium silicates have shown a promising combination of very low and good thermomechanical properties. The focus of this thesis is threefold: In the first part, phase transformations in plasma sprayed ytterbium silicates were investigated. Plasma sprayed materials are known to contain large amounts of amorphous material. Phase changes during the conversion from amorphous to crystalline materials were investigated as they have been known to lead to failure in many coatings. The second part of this work focused on measuring residual stresses in multilayer EBCs using synchrotron X-ray diffraction (XRD). Strains were resolved spatially, with probe sizes as small as 20 um. Stresses were calculated using mechanical properties of ytterbium silicates, determined with in-situ loading and heating experiments. In-situ and ex-situ heating experiments allowed for the study of changes in stress states that occur in these EBC materials during heating and cooling cycles. Lastly, the interaction of ytterbium silicates with low-melting environmental calcium-magnesium-aluminosilicate (CMAS) glasses was studied. Synchrotron XRD was used to study the influence of CMAS on the stress state in the coating, X-ray computed tomography was used to provide 3D images of coatings, and EDS and TEM analysis were used to study the interactions at the CMAS/ytterbium silicate interface in detail.

Stolzenburg, Fabian

115

Ocean Drilling Program Janus Database: Legs 174, 175 Data  

NSDL National Science Digital Library

Data from Leg 174A (Cork Hole 395A), Leg 174B (Continuing the New Jersey Mid-Atlantic Sea-level Transect), and Leg 175 (Benguela Current) of the Ocean Drilling Program (ODP) are now available online. The Ocean Drilling Program (described in the August 5, 1998 Scout Report for Science & Engineering) conducts basic research into the "history of the ocean basins and the nature of the crust beneath the floor." ODP is funded principally by the National Science Foundation (NSF), along with large contributions from ODP's international partners.

116

Highly efficient cladding-pumped fibre laser based on an ytterbium-doped optical fibre and a fibre Bragg grating  

SciTech Connect

Ytterbium-ion-doped double-clad optical fibres were developed. The differential quantum efficiency of a diode-pumped fibre laser, fabricated on the basis of such optical fibres with a fibre Bragg grating, was 90%. (lasers)

Kurkov, Andrei S; Karpov, V I; Medvedkov, O I; Dianov, Evgenii M; Vasil'ev, Sergei A; Paramonov, Vladimir M; Protopopov, V N [Fiber Optics Research Center, Russian Academy of Sciences, Moscow (Russian Federation); Laptev, A Yu; Gur'yanov, A N; Umnikov, A A; Vechkanov, N I [Institute of Chemistry of High-Purity Substances, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation); Artyushenko, V G; Frahm, J [Advanced Photonic Systems, APhS GmbH, Berlin (Germany)

1999-06-30

117

Preventing photodarkening in ytterbium-doped high power fiber lasers; correlation to the UV-transparency of the core glass.  

PubMed

Photodarkening experiments are performed on ytterbium-doped silicate glass samples. A strong charge-transfer (CT) absorption band near 230nm in aluminosilicate glass is found to be correlated to the mechanism of induced color center formation. Excitation into the CT-absorption band generates similar color centers as observed in ytterbium-doped fiber lasers under 915nm high power diode pumping. The position of the CT-absorption band is compositional dependent and is shifted to shorter wavelengths in ytterbium doped phosphosilicate glass. Very low levels of photodarkening is observed for the ytterbium doped phosphosilicate glass composition under 915nm high power diode pumping. Possible excitation routes to reach the CT-absorption band under 915nm pumping are discussed. PMID:18542200

Engholm, M; Norin, L

2008-01-21

118

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2012 CFR

...Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260 Food...Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section and...

2012-04-01

119

21 CFR 175.260 - Partial phosphoric acid esters of polyester resins.  

Code of Federal Regulations, 2011 CFR

...Partial phosphoric acid esters of polyester resins. 175.260 Section 175.260 Food...Partial phosphoric acid esters of polyester resins. Partial phosphoric acid esters of polyester resins identified in this section and...

2011-04-01

120

21 CFR 175.360 - Vinylidene chloride copolymer coatings for nylon film.  

Code of Federal Regulations, 2010 CFR

...Vinylidene chloride copolymer coatings for nylon film. 175.360 Section 175.360...Vinylidene chloride copolymer coatings for nylon film. Vinylidene chloride copolymer...identified in this section and applied on nylon film may be safely used as...

2009-04-01

121

21 CFR 175.360 - Vinylidene chloride copolymer coatings for nylon film.  

Code of Federal Regulations, 2010 CFR

...Vinylidene chloride copolymer coatings for nylon film. 175.360 Section 175.360...Vinylidene chloride copolymer coatings for nylon film. Vinylidene chloride copolymer...identified in this section and applied on nylon film may be safely used as...

2010-01-01

122

40 CFR 417.175 - Standards of performance for new sources.  

Code of Federal Regulations, 2013 CFR

...Section 417.175 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Detergents by Dry Blending Subcategory § 417.175...

2013-07-01

123

49 CFR 175.701 - Separation distance requirements for packages containing Class 7 (radioactive) materials in...  

Code of Federal Regulations, 2013 CFR

...radioactive) materials in passenger-carrying aircraft. 175.701 Section 175.701 Transportation...HAZARDOUS MATERIALS REGULATIONS CARRIAGE BY AIRCRAFT Specific Regulations Applicable According...radioactive) materials in passenger-carrying aircraft. (a) The following table...

2013-10-01

124

26 CFR 1.175-2 - Definition of soil and water conservation expenditures.  

Code of Federal Regulations, 2010 CFR

...false Definition of soil and water conservation expenditures. 1.175-2...175-2 Definition of soil and water conservation expenditures. (a) Expenditures...for the purpose of soil or water conservation in respect of...

2009-04-01

125

26 CFR 1.175-2 - Definition of soil and water conservation expenditures.  

Code of Federal Regulations, 2013 CFR

...false Definition of soil and water conservation expenditures. 1.175-2...175-2 Definition of soil and water conservation expenditures. (a) Expenditures...for the purpose of soil or water conservation in respect of...

2013-04-01

126

26 CFR 1.175-2 - Definition of soil and water conservation expenditures.  

Code of Federal Regulations, 2010 CFR

...false Definition of soil and water conservation expenditures. 1.175-2...175-2 Definition of soil and water conservation expenditures. (a) Expenditures...for the purpose of soil or water conservation in respect of...

2010-04-01

127

49 CFR 40.175 - What steps does the first laboratory take with a split specimen?  

Code of Federal Regulations, 2010 CFR

...steps does the first laboratory take with a split specimen? 40.175 Section 40.175...WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Split Specimen Tests § 40.175 What steps does the first laboratory take with a split specimen? (a) As the laboratory...

2009-10-01

128

49 CFR 40.175 - What steps does the first laboratory take with a split specimen?  

Code of Federal Regulations, 2010 CFR

...steps does the first laboratory take with a split specimen? 40.175 Section 40.175...WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Split Specimen Tests § 40.175 What steps does the first laboratory take with a split specimen? (a) As the laboratory...

2010-10-01

129

50 CFR 300.175 - Hail-in and hail-out reports.  

Code of Federal Regulations, 2010 CFR

...Fisheries 7 2010-10-01 2010-10-01 false Hail-in and hail-out reports. 300.175 Section 300.175 Wildlife...REGULATIONS Pacific Albacore Tuna Fisheries § 300.175 Hail-in and hail-out reports. (a) The...

2010-10-01

130

50 CFR 300.175 - Hail-in and hail-out reports.  

Code of Federal Regulations, 2010 CFR

...Fisheries 7 2009-10-01 2009-10-01 false Hail-in and hail-out reports. 300.175 Section 300.175 Wildlife...REGULATIONS Pacific Albacore Tuna Fisheries § 300.175 Hail-in and hail-out reports. (a) The...

2009-10-01

131

50 CFR 300.175 - Hail-in and hail-out reports.  

Code of Federal Regulations, 2013 CFR

...Fisheries 11 2013-10-01 2013-10-01 false Hail-in and hail-out reports. 300.175 Section 300.175 Wildlife...REGULATIONS Pacific Albacore Tuna Fisheries § 300.175 Hail-in and hail-out reports. (a) The...

2013-10-01

132

KNb1.75V0.25PS10  

PubMed Central

The title compound, potassium diniobium vanadium phospho­rus deca­sulfide, KNb1.75V0.25PS10, was obtained by reaction of the elements with a eutectic mixture of KCl/LiCl. It is isostructural with the quaternary KNb2PS10, but the Nb sites are occupied by statistically disordered Nb (87.5%) and V (12.5%) atoms. The structure is composed of anionic ? 1[M 2PS10]? chains (M = Nb/V) separated from each other by K+ ions. The chain is composed of [MS8] distorted bicapped trigonal prisms and [PS4] tetra­hedra. There are no inter­chain bonding inter­actions. The crystal used for the X-ray analysis was a racemic twin.

Yu, Jaemin; Yun, Hoseop

2011-01-01

133

Band Structures and Nucleon Alignments in ^173,175W  

NASA Astrophysics Data System (ADS)

Spectroscopic study of nuclei in the A˜180 region is essential to better understand regional relationships between Nilsson orbitals. Highly excited rotational states in both nuclei were populated at Argonne National Laboratory via a 230 MeV ^50Ti beam from the ATLAS accelerator incident on a ^128Te target. The Gammasphere array was used to detect ? decays from excited states. Rotational bands built on the level 1/2^-[521], p3/2 in ^173,175W have been extended to spins of 40 and 35 respectively, and bands built on the 7/2^+[633], i13/2 configuration extended to 38 and 27 respectively. New sidebands in ^173W have been observed in all previously-discovered bands. Alignments from i13/2 neutron and h11/2 proton crossings are consistent with predictions of Woods-Saxon cranking calculations. Experimental results and regional systematics will be presented.

Guess, C. J.; Tandel, S. K.; Chowdhury, P.; Shirwadkar, U.; Carpenter, M. P.; Janssens, R. V. F.; Khoo, T. L.; Lauritsen, T.; Lister, C. J.; Seweryniak, D.; Wang, X.; Zhu, S.; Hartley, D. J.

2012-10-01

134

Nano-level monitoring of ytterbium(III) by a novel ytterbium(III) membrane sensor based on 3-hydroxy- N?-[(2-hydroxyphenyl) methylene]-2-naphthohydrazide  

Microsoft Academic Search

In this work, a highly sensitive ytterbium(III)-selective solvent polymeric membrane sensor based on 3-hydroxy-N?-[(2-hydroxyphenyl)methylene]-2-naphthohydrazide (HPMN), poly(vinyl chloride) (PVC), the plasticizer dibutyl phthalate (DBP), and sodium tetraphenyl borate (NaTPB) anionic site is described. This sensor responds to Yb(III) activity in a linear range from 1.0×10?7 to 1.0×10?2M, with a slope of 19.2±0.2mV per decade and a detection limit of 4.0×10?8M at

Mohammad Reza Ganjali; Parviz Norouzi; Atefeh Tamaddon; Mehdi Adib

2006-01-01

135

Microstructure and oxidation behavior of ReSi 1.75 synthesized by spark plasma sintering  

Microsoft Academic Search

Synthesis and sintering of ReSi1.75 were simultaneously performed by a spark plasma sintering method, using the mixed powders of elemental Re and Si. The interface structure between Re and Si changed with temperature as follows: Re\\/ReSi1.75\\/Si, Re\\/Re5Si3\\/ReSi1.75, and Re\\/Re5Si3\\/ReSi\\/ReSi1.75. On the basis of the results on the interfacial reaction, a compact body consisting of the single phase ReSi1.75 could be

Kazuya Kurokawa; Hisashi Hara; Hideaki Takahashi; Heishichiro Takahashi

2002-01-01

136

Optical properties of ytterbium-doped tandem-pumped fiber oscillator  

NASA Astrophysics Data System (ADS)

With the rapid development of ytterbium-doped fiber lasers, some obtrusive limitations on power scaling appeared. In order to avoid these problems, a scheme called tandem pumping is introduced into the fiber laser field. In this paper, the optical properties of an ytterbium-doped tandem-pumped fiber oscillator are presented. According to the oscillator profile, the proper gain fiber type and pump wavelength range are picked out, under the comprehensive consideration of laser conversion efficiency and beam quality. In addition, the photodarkening performances of tandem pumping lasers and conventional ones are compared based on practical application, with all possible impact parameters taken into account. Moreover, an all-fibered tandem-pumped oscillator centered at 1079.5 nm is built, in the way of clad pumping by a 1030-nm fiber laser. The laser power of the oscillator reaches 7 W, with an opto-optic efficiency of 82.4%.

Hao, Jin-Ping; Yan, Ping; Xiao, Qi-Rong; Li, Dan; Gong, Ma-Li

2014-01-01

137

Electrical resistance measurements in a diamond anvil cell to 40 GPa on ytterbium  

NASA Astrophysics Data System (ADS)

An easily assembled setup employing diamond anvil cell, stainless steel gasket and leads, and mylar embedded Al2O3 (alumina) pressure medium for the measurement of electrical resistance of materials under pressure is described. The use of a mylar sheet prevents the alumina layer from sticking to the anvil in the precompacting stage of Al2O3 and also reduces the pressure gradients in the final assembly. The technique is used to reproduce the known transition in Si, Ge, and Fe. The results of measurements of electrical resistance of ytterbium up to 40 GPa are reported. In the hcp phase of ytterbium the electrical resistance increases with pressure. Efforts are made to explain the variation of resistance with pressure from known band structure calculations.

Garg, Alka B.; Vijayakumar, V.; Godwal, B. K.

2004-07-01

138

Thulium and Ytterbium-Doped Titanium Oxide Thin Films Deposited by Ultrasonic Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Thin films of thulium and ytterbium-doped titanium oxide were grown by metal-organic spray pyrolysis deposition from titanium(IV)oxide bis(acetylacetonate), thulium(III) tris(2,2,6,6-tetramethyl-3,5-heptanedionate) and ytterbium(III) tris(acetylacetonate). Deposition temperatures have been investigated from 300 to 600 °C. Films have been studied regarding their crystallinity and doping quality. Structural and composition characterisations of TiO2:Tm,Yb were performed by electron microprobe, x-ray diffraction, and Fourier transform infrared spectroscopy. The deposition rate can reach 0.8 ?m/h. The anatase phase of TiO2 was obtained after synthesis at 400 °C or higher. Organic contamination at low deposition temperature is eliminated by annealing treatments.

Forissier, Sébastien; Roussel, Hervé; Chaudouet, Patrick; Pereira, Antonio; Deschanvres, Jean-Luc; Moine, Bernard

2012-12-01

139

Ytterbium-porphyrins as a new class of the luminescent labels  

NASA Astrophysics Data System (ADS)

New complexes of ytterbium with asymmetric porphyrins containing substituents in ?-positions and hydrophobic meso-(monophenyl-p-oxypropyl)triphenylporphyrin (OPP) were obtained and characterized by elemental analysis, IR, UV-Vis absorption and luminescence spectroscopy. Electronic absorption, luminescence and luminescence excitation spectra of these complexes were studied at 295 K in DMF solutions and in the water-lecithin medium. The 4f-luminescence of ytterbium-porphyrins in the near infrared (IR) spectral region (?max = 980 nm) is observed under excitation in Soret band (400-430 nm). The effect of substituent in porphyrin macroring on the 4f-luminescent properties was also investigated. The conjugates of these compounds with protein molecules - bovine serum albumin (BSA) were investigated as well. These compounds are interesting at the initial stage of diagnostics of tumor tissues as IR-luminescent probes due to their spectral-luminescent characteristics and some biochemical properties.

Tsvirko, M.; Korovin, Yu; Rusakova, N.

2007-08-01

140

Efficient ytterbium triflate catalyzed microwave-assisted synthesis of 3-acylacrylic acid building blocks.  

PubMed

The derivatives of 4-(hetero)aryl-4-oxobut-2-enoic acid are useful as building blocks in the synthesis of biologically active compounds. An efficient general protocol for the synthesis of these building blocks was developed. This method combines microwave assistance and ytterbium triflate catalyst and allows the fast preparation of the target acids starting from different (hetero)aromatic ketones and glyoxylic acid monohydrate giving pure products in 52-75% isolated yields. PMID:18715040

Tolstoluzhsky, Nikita V; Gorobets, Nikolay Yu; Kolos, Nadezhda N; Desenko, Sergey M

2008-01-01

141

Solubility products, thermodynamic functions and stability constants for the praseodymium and ytterbium fluoride — Water systems  

Microsoft Academic Search

The solubility products and thermodynamic functions for the praseodymium and ytterbium fluoride-water systems have been measured using different analytical techniques for comparison among the measured values as well as with values reported in literature. Although there is not much difference among our values obtained by potentiometric, conductometric and radiometric methods, the values for PrF3 disagree with at least two of

M. P. Menon; J. James; R. Abbas

1989-01-01

142

Model of Temperature Dependence Shape of Ytterbium -doped Fiber Amplifier Operating at 915 nm Pumping Configuration  

Microsoft Academic Search

We numerically analyze the temperature dependence of an ytterbium-doped fiber amplifier (YDFA) operating at 915 nm, investigating its gain and Noise Figure properties variation with temperature. The temperature-dependent gain and noise figure variation with YDFA length are numerically obtained for the temperature range of +20 0C to +70 0C. The results show that good intrinsic output stability against temperature change

Fady I. EL-Nahal Abdel Hakeim M

2011-01-01

143

Experimental Performance of a Single-Mode Ytterbium-doped Fiber Ring Laser with Intracavity Modulator  

NASA Technical Reports Server (NTRS)

We have developed a linearly polarized Ytterbium-doped fiber ring laser with a single longitudinal mode output at 1064 run. A fiber-coupled intracavity phase modulator ensured mode-hop free operation and allowed fast frequency tuning. The fiber laser was locked with high stability to an iodine-stabilized laser, showing a frequency noise suppression of a factor approx 10 (exp 5) at 1 mHz

Numata, Kenji; Camp, Jordan

2012-01-01

144

Efficient compression of the femtosecond pulses of an ytterbium laser in a gas-filled capillary  

SciTech Connect

A 290-fs radiation pulse of an ytterbium laser system with a central wavelength of 1028 nm and an energy of 145 {mu}J was compressed to a 27-fs pulse with an energy of 75 {mu}J. The compression was realised on the basis of the effect of pulse spectrum broadening in a xenon-filled glass capillary for a pulse repetition rate of 3kHz. (control of laser radiation parameters)

Konyashchenko, Aleksandr V; Losev, Leonid L; Tenyakov, S Yu

2011-07-31

145

Tunable, ?s-pulsed ytterbium fiber laser system with a linewidth below 2.7 GHz  

NASA Astrophysics Data System (ADS)

We report on a widely tunable, pulsed laser system with narrow spectral linewidth based on a continuous wave ytterbium fiber oscillator, a pulse shaper and a power amplifier stage. The system is tunable from 1055 nm to 1085 nm and provides a maximum pulse energy of 155 ?J with a pulse duration of 1-5 ?s. The linewidth is less than 2.7 GHz over the whole tuning range.

Engelbrecht, M.; Wandt, D.; Kracht, D.

2007-11-01

146

Optimization of pulse amplification in ytterbium-doped double-clad fiber amplifiers  

Microsoft Academic Search

In the present paper, high-power continuous-wave (CW)-pumped ytterbium-doped double-clad (YDDC) fiber amplifiers for the amplification of nanosecond pulses with tens of kilohertz repetition rates are numerically studied. Targeting pulse energy and average output power, the fiber amplifiers under forward, backward, and bidirectional pump are systematically analyzed and optimized in consideration of pump and signal wavelengths, pulse repetition rate, fiber structure

Yong Wang

2005-01-01

147

Diode-pumped 1028 nm Ytterbium-doped fiber laser with near 90% slope efficiency  

Microsoft Academic Search

Highly efficient laser action from an Ytterbium-doped fiber (YDF) is demonstrated using a fiber Bragg grating (FBG) in conjunction\\u000a with a 4% Fresnel reflection at room temperature. The YDF used is drawn from Yb2O3-doped preform, fabricated through deposition of porous layer of composition SiO2-GeO2 by the MCVD process in conjunction with a solution doping technique. The fabricated YDF has a

S. W. Harun; M. C. Paul; M. R. A. Moghaddam; S. Das; R. Sen; A. Dhar; M. Pal; S. K. Bhadra; H. Ahmad

2010-01-01

148

N-type Schottky barrier source\\/drain MOSFET using ytterbium silicide  

Microsoft Academic Search

Ytterbium silicide, for the first time, was used to form the Schottky barrier source\\/drain (S\\/D) of N-channel MOSFETs. The device fabrication was performed at low temperature, which is highly preferred in the establishment of Schottky barrier S\\/D transistor (SSDT) technology, including the HfO2 gate dielectric, and HaN\\/TaN metal gate. The YbSi2 - x silicided N-SSDT has demonstrated a very promising

Shiyang Zhu; Jingde Chen; M.-F. Li; S. J. Lee; Jagar Singh; C. X. Zhu; Anyan Du; C. H. Tung; Albert Chin; D. L. Kwong

2004-01-01

149

Ytterbium-doped high power fiber lasers with fused fiber bundle combiner  

Microsoft Academic Search

Ytterbium (Yb3+)-doped high power fiber lasers are attractive because of high efficiency, high power and good beam quality, which have many potential applications in telecommunication, machining and national defense. Most of the high power Yb3+-doped double-clad (DC) fiber lasers use end pump technology, which is the conventional method to couple pump lights into the inner cladding. However, this pump method

Jihuang Zhang; Chuan Huang; Chao Yang; Yuhua Li; Wei Chen; Peixiang Lu

2008-01-01

150

High power, continuous-wave ytterbium-doped fiber laser tunable from 976 to 1120 nm.  

PubMed

We report on a linearly-polarized, continuous-wave Ytterbium-doped fiber laser continuously tunable on the fly over an unprecedented emission bandwidth ranging from 976 nm to 1120 nm and delivering a minimum of 10 W and a maximum of 41 W. Additionally, the bandwidth of the system can be tuned from 100 pm to more than 1 nm at all wavelengths. PMID:23736636

Royon, Romain; Lhermite, Jérome; Sarger, Laurent; Cormier, Eric

2013-06-01

151

Broadband diode-pumped ytterbium-doped fiber amplifier with 34 dBm output power  

Microsoft Academic Search

We investigate a high-power diode-pumped double-clad ytterbium-doped fiber amplifier with 34 dB m average output power and 1050 - 1095 nm bandwidth. A multi-diode concentrator pumps the amplifier at 980 nm, with ~6 W of power launched into the inner cladding. Besides cw-signals, we amplify pulses from a mode-locked laser to 1 kW of peak power with only minor nonlinear

J. M. Sousa; J. Nilsson; C. C. Renaud; J. A. Alvarez-Chavez; A. B. Grudinin; J. D. Minelly

152

Spectroscopic studies on proton-rich nucleus ^175Pt  

NASA Astrophysics Data System (ADS)

Neutron-deficient nuclei around the Z=82 shell closure are known to exhibit shape coexsistence, due to the interplay between the occupation of specific intruder orbitals and core effects. It is challenging to study such nuclei experimentally, since fission dominates and, as a consequence, evaporation residue cross sections are small. The Recoil Decay Tagging (RDT) technique combined with the use of a large gamma-ray array is a powerful tool to study such nuclei. ^175Pt was investigated with this approach to clarify the structure of this nucleus and to extend the systematics in this region. Excited states were populated by the ^94Mo(^84Sr,2pn) reaction at beam energies of 380 and 385 MeV provided by ATLAS. Prompt gamma rays were detected by Gammasphere and the recoiling nuclei were identified according to their m/q ratio using the FMA. After m/q identification, the recoiling nuclei were implanted in a 40x40 DSSD, where subsequent charge particle decays were measured. An array of four large-volume Ge detectors and one LEPS detector surrounded the DSSD. The results of this measurement will be presented. This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.

Gürdal, G.; Carpenter, M. P.; Kondev, F. G.; Janssens, R. V. F.; Ahmad, I.; Khoo, T. L.; Lauritsen, T.; Lister, C. J.; Seweryniak, D.; Zhu, S.; Hartley, D. J.; Riedinger, L. L.

2010-11-01

153

[Double cladding ytterbium doped superfluorescence fiber source with 3 dB bandwidth reaching up to 80 nm].  

PubMed

The present paper reports a double pass forward superfluorescent fiber source (SFS), which uses a length of large mode area double cladding ytterbium doped fiber as gain medium. The maximum output power of this SFS is 341 mW. With the output power between 201 and 341 mW, the 3dB bandwidth of this SFS was more than 80 nm. This is the widest 3 dB bandwidth obtained from ytterbium doped SFS. The output power of the SFS linearly increased with the increment of the pump source injected current. It's output power is not very high, but under normal circumstances, it could meet the needs of the SFS. From the energy level structure of ytterbium ions and the absorption cross-section/emission cross section of ytterbium ions in quartz substrate, the physical mechanisms responsible for superfluorescence were analyzed. This double-cladding ytterbium-doped superfluorescent fiber laser benefits from the superfluorescence radiation near 1 025 and 1 075 nm, so the superfluorescence with 3 dB bandwidth reaching up to 80 nm could be obtained. PMID:23387175

Han, Xu; Feng, Guo-Ying; Han, Jing-Hua; Wu, Chuan-Long; Zhou, Shou-Huan

2012-11-01

154

Primary empty sella (PES): a review of 175 cases.  

PubMed

The term primary empty sella (PES) makes reference to the herniation of the subarachnoid space within the sella turcica in patients with no history of pituitary tumor, surgery or radiotherapy. To retrospectively assess clinical features, radiological findings and the biochemical endocrine function from the records of 175 patients with a diagnosis of PES. One hundred seventy-five patients (150 females) were studied. The mean age at diagnosis was 48.2 ± 14 year. Most diagnoses were made by magnetic resonance imaging (n = 172). In most patients, the pituitary function was assessed by basal pituitary hormones measurements. Pituitary scans were ordered for different reasons: headache (33.1 %), endocrine disorders (30.6 %), neurological symptoms (12.5 %), visual disturbances (8.75 %), abnormalities on sella turcica radiograph (8.75 %) and others (6.25 %). Multiple pregnancies were observed in 58.3 % of women; headaches, obesity, and hypertension were found in 59.4, 49.5, and 27.3 % of the studied population, respectively. Mild hyperprolactinemia (<50 ng/ml) was present in 11.6 % of women and 17.3 % of men. Twenty-eight percent of our patients had some degree of hypopituitarism. In the male population, hypopituitarism represented 64 % of cases, whereas it accounted for 22 % of all females. PES seems to be more commonly found in middle-aged women, with a history of multiple pregnancies. In most patients, PES was discovered as an incidental finding on imaging studies, while in almost a quarter of patients PES was found during the diagnostic evaluation of anterior pituitary deficiency, which was more common in men. PMID:22875743

Guitelman, M; Garcia Basavilbaso, Natalia; Vitale, M; Chervin, A; Katz, D; Miragaya, K; Herrera, J; Cornalo, D; Servidio, M; Boero, L; Manavela, M; Danilowicz, K; Alfieri, A; Stalldecker, G; Glerean, M; Fainstein Day, P; Ballarino, C; Mallea Gil, Maria Susana; Rogozinski, A

2013-06-01

155

Detection of divalent europium, ytterbium, and samarium ions in aqueous solution during anodic polarization of the corresponding amalgam  

SciTech Connect

Amalgams of europium, ytterbium, and samarium are oxidized both at constant current and at constant potential. It was found experimentally that the potential of the indicator electrode moved to negative values when the circuit was closed and anodic current (1.0 to 60.0 mA) or potential (of the starting wave, half wave, or limiting current) applied. The potential of the microelectrode was 0.05 V, and remained unchanged during the entire electrolysis time, when pure mercury was used as the anode. The data reported for europium, ytterbium, and samarium amalgam confirm the results otained previously. By measuring the redox potentials of couples Sm/sup 3 +/-Sm/sup 2/, Yb/sup 3 +/-Yb/sup 2 +/ and Eu/sup 3 +/-Eu/sup 2 +/ directly at the electrode surface the authors have established the formation of divalent samarium, ytterbium, and europium ions during anodic oxidation of the corresponding amalgams.

Sagadieva, K.Z.; Badavamova, G.L.; Zebreva, A.I.

1986-04-01

156

Ytterbium-doped large-mode-area photonic crystal fiber amplifier with gain shaping for use at long wavelengths  

NASA Astrophysics Data System (ADS)

A large-mode-area Ytterbium-doped photonic crystal fiber amplifier with efficient suppression of amplified spontaneous emission is presented. The fiber cladding consists of a hexagonal lattice of air holes, where three rows are replaced with circular high-index inclusions. Seven missing air holes define the large-mode-area core. Light confinement is achieved by combined index and bandgap guiding, which allows for single-mode operation and distributed spectral filtering of amplified spontaneous. The fiber properties give control of the gain shape and are ideal for amplification in the long wavelength regime of the Ytterbium gain spectrum above 1100 nm.

Petersen, Sidsel R.; Alkeskjold, Thomas T.; Poli, Federica; Coscelli, Enrico; Jørgensen, Mette M.; Laurila, Marko; Lægsgaard, Jesper; Broeng, Jes

2012-02-01

157

Influence of multimode-pump propagation on the gain characteristics of erbium–ytterbium doped waveguide amplifier  

Microsoft Academic Search

Channel waveguides with channel opening widths (COWs) from 4.5 to 7.5 ?m with increment of 0.5 ?m have been fabricated by\\u000a two-step ion exchange on the same erbium-ytterbium uniformly doped phosphate glass substrate of 4.3-cm length. Experimental\\u000a results indicate that the gain for 1534-nm small signal light pumped at saturation is maximized and shows a 3.6-dB enhancement\\u000a for these erbium-ytterbium doped waveguide

G. Shao; G. Jin; L. Zhan; Q. Li

2009-01-01

158

Studies of the nonautonomous state of ytterbium nanofilms induced by chemisorbed oxygen molecules by means of photoelectron spectroscopy  

NASA Astrophysics Data System (ADS)

The effect of chemisorbed oxygen molecules on the electron structure of ytterbium films of nanosized thicknesses has been studied by means of high-resolution photoelectron spectroscopy. It has been demonstrated that, in the process of chemisorption of O2 molecules, the subsurface layers of ytterbium films transform from a two-valence state into a three-valence one. Estimation of the depth of disturbance induced by molecules has been performed. The estimates reveal that the above depth can attain very large values: up to 22 film layers, or 7.5 nm.

Buturovich, D. V.; Kuz'min, M. V.; Mittsev, M. A.

2012-11-01

159

DIVALENT LANTHANIDE CHEMISTRY; BIS (PENTAMETHYLCYCLOPENTADIENYL) EUROPIUM(II) AND YTTERBIUM(II) DERIVATIVES: CRYSTAL STRUCTURE OF BIS(PENTAMETHYLCYCLOPENTADIENYL) YTTERBIUM (II)TETRAHYDROFURAN HEMI (TOLUENE) AT 176K  

SciTech Connect

Red, paramagnetic ({mu}{sub B} = 7.99 B.M., 5-50K) bis(pentamethylcyclopentadienyl) europium (II)(tetrahydrofuran)(diethylether), (Me{sub 5}C{sub 5}){sub 2}Eu(THF)(Et{sub 2}O) is isolated from reaction of three molar equivalents of sodium pentamethylcyclopentadienide and europium trichloride in refluxing tetrahydrofuran, after crystallization from diethyl ether. The monotetrahydrofuran complex, (Me{sub 5}C{sub 5}){sub 2}Eu(THF), may be isolated by use of toluene rather than diethyl ether as the crystallization solvent. Red, diamagnetic bis(pentamethylcyclopentadienyl)ytterbium(II)(tetrahydrofuran) is isolated from the reaction of ytterbium dichloride and sodium pentamethylcyclopentadienide in refluxing tetrahydrofuran. The diethyl ether complex, (Me{sub 5}C{sub 5}){sub 2}Yb(OEt{sub 2}), may be isolated by crystallization of the tetrahydrofuran complex from diethylether, The hemi-toluene complex, (Me{sub 5}C{sub 5}){sub 2} Yb(THF) {center_dot} 1/2 toluene, can be isolated by recrystallization of the tetrahydrofuran complex from toluene. As these divalent metallocenes are the first hydrocarbon-soluble lanthanide derivatives to be isolated we have examined the latter complex by X-ray crystallography. Crystals of (Me{sub 5}C{sub 5}){sub 2}Yb(OC{sub 4}H{sub 8}) {center_dot} 1/2(C{sub 6}H{sub 5}cH{sub 3}) crystalline in the monoclinic system, P2{sub 1}/n, with a = 11.358(8) {angstrom}, b = 21.756(19) {angstrom}, c = 10.691(7) {angstrom}, and {beta} = 101.84(5){sup o} at 176K. For Z = 4 the calculated density is 1.37 g cm{sup -3}. The ytterbium atom is coordinated to the oxygen atom of a tetrahydrofuran molecule and to two pentamethyl cyclopentadienyl rings. The molecule has approximate c{sub 2} symmetry about the Yb-0 bond. The Yb-0 distance is 2.41 {angstrom}, the Yb-C distances average 2.66 {angstrom}, and the Yb-Cp (centroid) distances average 2.37 {angstrom}. The Me{sub 5}C{sub 5} rings are in a staggered configuration with respect to each other. The methyl groups of the Me{sub 5}C{sub 5} groups are displaced by .03 to .21 {angstrom} from the planes of the five-membered rings away from the ytterbium atom. The toluene molecule is not coordinated to the complex and is on a center of symmetry in a disordered configuration. The 3466 data with F{sup 2} > 3{sigma} refined by full matrix least-squares to a conventional R factor of 0.036.

Tilley, T.Don; Andersen, Richard A.; Spencer, Brock; Ruben, Helena; Zalkin, Allan; Templeton, David H.

1980-04-01

160

Erbium-ytterbium-yttrium compounds for light emission at 1.54microm  

NASA Astrophysics Data System (ADS)

Silicon microphotonics? has emerged as the leading technology to overcome the interconnect bottleneck that limits a further increase of computation power following Moore's law. Optical interconnects between different electronic microprocessors in an electronic-photonic integrated circuit (EPIC) can provide a fast, low-loss and highbandwidth alternative to electrical interconnects, which suffer from issues such as resistive heating, RC delays and channel crosstalk at an increasing device density. A crucial device in such an electronic-photonic integrated circuit is a compact, highgain and low power optical amplifier to compensate for signal attenuation due to propagation losses and to recover signal strength after subsequent 3dB splits during fanout of the optical signal to different microprocessors. Erbium ions (Er3+) are an excellent candidate to provide amplification around .. = 1.54pm for optical telecommunications. Erbium-doped fiber amplifiers (EDFAs) have already enabled long-haul optical data. transmission through silica optical fibers, but scaling down a fiber amplifier to an on-chip erbium-doped waveguide amplifier (EDWA) brings along significant materials and device design challenges. In this thesis, erbium-ytterbium oxide (Erx Yb2-xO 3) and erbium-ytterbium-yttrium silicate (ErxYhyY 2-x-ySi2O7) compounds are investigated as novel materials systems for the development of EDWAs. The high erbium and ytterbium solubility (>1022 cm-3) and refractive index (1.71 < n < 1.92) make these materials excellent candidates for compact, low-power optical amplifiers. Erx Yb2-xO 3 and ErxYhyY2-x-ySi2O 7 thin films were deposited on SiO2 and analyzed structurally and optically. The role of ytterbium in these compounds is twofold. First, ytterbium can be used as an alternative to yttrium for dilution of the erbium concentration in order to mitigate parasitic concentration quenching effects. Second, ytterbium acts as a sensitizer for erbium during optical pumping at lambda = 980nm. Comparison of the different oxide and silicate thin films reveals that the alpha-disilicate phase is the best candidate for an EDWA gain medium pumped at lambda = 980nm. By means of rate and propagation equations, the composition of an Er xYhyY2-x-ySi2O7 gain medium was optimized for application as a 3dB EDWA. The optimal composition was found to be Er0.025Yb0.200Yb0.200Y1.775Si 2O7, which provides a 1.5dB/cm gain at only 3mW of pump power. In terms of the figure of merit 3dB gain/(device area ? pump power), this material outperforms other EDWA materials reported in literature. (Copies available exclusively from MIT Libraries, libraries.mit.edu/docs - docs mit.edu)

Vanhoutte, Michiel

161

Temporal evolution and correlation between cooperative luminescence and photodarkening in ytterbium doped silica fibers.  

PubMed

The present work describes photodarkening from the viewpoint of cooperative luminescence. The temporal evolution of both effects was measured simultaneously by means of ytterbium doped aluminosilicate fibers for concentrations up to 1.8 wt% Yb3+. The quadratic dependence of photodarkening and cooperative luminescence versus dopant concentration was observed. The change in the photodarkening and cooperative luminescence mutual dynamics for highly and low doped fibers is ascribed to a different ion number which forms the cluster. Cooperative luminescence is proved to be a natural probe for photodarkening since it provides new pieces of information and contributes to the photodarkening mechanism description. PMID:22273899

Gebavi, Hrvoje; Taccheo, Stefano; Milanese, Daniel; Monteville, Achille; Le Goffic, Olivier; Landais, David; Mechin, David; Tregoat, Denis; Cadier, Benoit; Robin, Thierry

2011-12-01

162

The hyperfine interaction in the odd isotope of ytterbium fluoride, 171YbF  

NASA Astrophysics Data System (ADS)

The pure rotational spectrum of a minor isotopologue of ytterbium fluoride, 171YbF, in the X2?+ (v = 0) state has been recorded using Fourier transform microwave (FTMW) spectroscopy and pump/probe microwave optical double resonance (PPMODR) spectroscopy. The pure rotational spectra and precisely measured splittings in the (0, 0) A2?1/2 ? X2?+ band were analyzed to produce an improved set of fine and magnetic hyperfine parameters for the X2?+ (v = 0) state of 171YbF. A comparison with theoretical predictions is made.

Glassman, Zachary; Mawhorter, Richard; Grabow, Jens-Uwe; Le, Anh; Steimle, Timothy C.

2014-06-01

163

Photoluminescence of porous silicon stain etched and doped with erbium and ytterbium  

NASA Astrophysics Data System (ADS)

A novel low cost process has been developed for application in porous silicon-based photodetectors and solar cells, where conventional doping processes are not affordable because of the high processing cost and technical difficulties. Ytterbium and erbium (Yb 3+-Er 3+) ions were introduced into luminescent porous silicon stain etched by thermal diffusion. Doping profiles were evaluated by energy-dispersive spectroscopy analysis. The visible and near-infrared photoluminescence of Yb 3+-Er 3+ co-doped stain-etched porous silicon layers is observed and evaluated under 980 nm pumping. Up-conversion processes that could improve the efficiency of silicon-based solar cells are detected.

Díaz-Herrera, B.; González-Díaz, B.; Guerrero-Lemus, R.; Hernández-Rodríguez, C.; Méndez-Ramos, J.; Rodríguez, V. D.

2009-02-01

164

Thermoluminescence characterization of traps involved in the photodarkening of ytterbium-doped silica fibers.  

PubMed

The photodarkening (PD) mechanisms of ytterbium-doped silica optical fibers have still not been elucidated, although hardening routes have been proposed. Most basic questions are still under debate about the assignment of the darkening excitation bands into the UV range, the nature of absorbing centers (photoionized centers or trapped carriers?), or of traps accepting photo-released carriers (electron or hole traps?). We used thermoluminescence measurements to characterize traps populated by different radiation types. It is notably demonstrated that photodarkening involves silica hole traps. The popular idea that color centers are formed upon carrier trapping is not consistent with our observations. PMID:21042343

Mady, Franck; Benabdesselam, Mourad; Blanc, Wilfried

2010-11-01

165

Optical Excitation and Decay Dynamics of Ytterbium Atoms Embedded in a Solid Neon Matrix  

SciTech Connect

Neutral ytterbium atoms embedded in solid neon qualitatively retain the structure of free atoms. Despite the atom-solid interaction, the 6s6p {sup 3}P{sub 0} level is found to remain metastable with its lifetimes determined to be in the range of ten to hundreds of seconds. The atomic population can be almost completely transferred between the ground level and the metastable level via optical excitation and spontaneous decay. The dynamics of this process is examined and is used to explicitly demonstrate that the transition broadening mechanism is homogeneous.

Xu, C.-Y.; Lu, Z.-T. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics and Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637 (United States); Hu, S.-M. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Hefei National Laboratory for Physical Science at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Singh, J.; Bailey, K.; Mueller, P.; O'Connor, T. P. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Welp, U. [Material Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2011-08-26

166

21 CFR 175.230 - Hot-melt strippable food coatings.  

Code of Federal Regulations, 2010 CFR

... 2009-04-01 2009-04-01 false Hot-melt strippable food coatings. 175.230 Section...Use as Components of Coatings § 175.230 Hot-melt strippable food coatings. Hot-melt strippable food coatings may be safely...

2009-04-01

167

21 CFR 175.230 - Hot-melt strippable food coatings.  

Code of Federal Regulations, 2010 CFR

...3 2010-01-01 2009-04-01 true Hot-melt strippable food coatings. 175.230 Section...Use as Components of Coatings § 175.230 Hot-melt strippable food coatings. Hot-melt strippable food coatings may be safely...

2010-01-01

168

49 CFR 38.175 - High-speed rail cars, monorails and systems.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 false High-speed rail cars, monorails and systems. 38.175 Section 38...38.175 High-speed rail cars, monorails and systems. (a) All cars for high-speed...steel-wheel-on-steel rail technology, and monorail systems operating...

2009-10-01

169

36 CFR 1192.175 - High-speed rail cars, monorails and systems.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false High-speed rail cars, monorails and systems. 1192.175 Section...1192.175 High-speed rail cars, monorails and systems. (a) All cars for high-speed...steel-wheel-on-steel-rail technology, and monorail systems operating...

2009-07-01

170

49 CFR 38.175 - High-speed rail cars, monorails and systems.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false High-speed rail cars, monorails and systems. 38.175 Section 38...38.175 High-speed rail cars, monorails and systems. (a) All cars for high-speed...steel-wheel-on-steel rail technology, and monorail systems operating...

2010-10-01

171

36 CFR 1192.175 - High-speed rail cars, monorails and systems.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false High-speed rail cars, monorails and systems. 1192.175 Section...1192.175 High-speed rail cars, monorails and systems. (a) All cars for high-speed...steel-wheel-on-steel-rail technology, and monorail systems operating...

2010-07-01

172

26 CFR 1.175-2 - Definition of soil and water conservation expenditures.  

Code of Federal Regulations, 2013 CFR

...2014-04-01 false Definition of soil and water conservation expenditures. 1.175-2... § 1.175-2 Definition of soil and water conservation expenditures. (a) Expenditures...paid or incurred for the purpose of soil or water conservation in respect of...

2014-04-01

173

33 CFR 165.T13-175 - Safety Zone; M/V DAVY CROCKETT, Columbia River.  

Code of Federal Regulations, 2011 CFR

...Safety Zone; M/V DAVY CROCKETT, Columbia River. 165.T13-175 Section 165.T13-175...Safety Zone; M/V DAVY CROCKETT, Columbia River. (a) Location: The following area...zone: (1) All waters of the Columbia River encompassed within the following four...

2011-07-01

174

49 CFR 38.175 - High-speed rail cars, monorails and systems.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 false High-speed rail cars, monorails and systems. 38.175...and Systems § 38.175 High-speed rail cars, monorails and systems. (a) All cars for high-speed rail systems, including but not limited to...

2013-10-01

175

Highly selective and responsive visible to near-IR ytterbium emissive probe for monitoring mercury(II).  

PubMed

A new lanthanide probe based on the fluorescence resonance energy transfer (FRET) process with the combination of ytterbium porphyrinate complex and a rhodamine?B derivative unit was synthesized to detect the Hg(2+) ion with responsive emission in the visible and near-IR region with a detection limit of 10??M. PMID:24425677

Zhang, Tao; Chan, Chi-Fai; Lan, Rongfeng; Wong, Wai-Kwok; Wong, Ka-Leung

2014-01-20

176

Pulsed current activated combustion synthesis and consolidation of nanostructured ReSi1.75  

NASA Astrophysics Data System (ADS)

Dense nanostructured ReSi1.75 was synthesized by the pulsed current activated combustion synthesis (PCACS) method within 2 min in one step from mechanically activated powders of Re and 1.75 Si. Simultaneous combustion synthesis and densification were accomplished under the combined effects of a pulsed current and mechanical pressure. Highly dense ReSi1.75 was produced under simultaneous application of 80 MPa of pressure and a pulsed current. The average grain size and mechanical properties (hardness and fracture toughness) of the compound were investigated.

Shon, In-Jin; Kim, Su-Chul; Lee, Byung-Soo; Kim, Byung-Ryang

2009-03-01

177

Normal-dispersion passively mode-locked ytterbium-doped fiber laser with a fundamental repetition rate higher than 400 MHz  

Microsoft Academic Search

We have developed a normal-dispersion passively mode-locked ytterbium-doped fiber laser with a fundamental repetition rate higher than 400 MHz at a wavelength of ~1085 nm by use of a short linear cavity design.

Dai Yoshitomi; Taisuke Kawasaki; Takashi Aoki; Yohei Kobayashi; Norio Nakamura; Tetsuya Homma; Hiroshi Kawata; Kenji Torizuka

2009-01-01

178

All-fiber 1085-nm wide supercontinuum source based on a mode-locked ytterbium fiber laser with dispersion compensation by a chirped fiber Bragg grating  

Microsoft Academic Search

The pulses of an ytterbium-fiber laser with dispersion compensation provided by a chirped fiber Bragg grating are amplified in a core-pumped fiber amplifier and broadened in a photonic crystal fiber to an octave spanning supercontinuum.

Robert Herda; Samuli Kivistö; Oleg G. Okhotnikov

2008-01-01

179

40 CFR 408.175 - Standards of performance for new sources.  

Code of Federal Regulations, 2013 CFR

...POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.175...this subpart: (1) Any mechanized salmon processing facility located in population...0 to 9.0. (2) Any mechanized salmon processing facility not covered...

2013-07-01

180

46 CFR 175.400 - Definitions of terms used in this subchapter.  

Code of Federal Regulations, 2013 CFR

...175.400 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS...familiarity with, but not limited to, the followingâ (i) The camera used during the AHE; and (ii) The NDT equipment...

2013-10-01

181

48 CFR 217.175 - Multiyear contracts for electricity from renewable energy sources.  

Code of Federal Regulations, 2010 CFR

...contracts for electricity from renewable energy sources. 217.175 Section...contracts for electricity from renewable energy sources. (a) The head...electricity from sources of renewable energy, as that term is defined...

2010-10-01

182

Complete Genome Sequences of Three Novel Human Papillomavirus Types, 175, 178, and 180  

PubMed Central

We report the characterization of three novel human papillomavirus (HPV) types of the genus Gammapapillomavirus. HPV175 and HPV180 were isolated from a condyloma. HPV178 was isolated from healthy skin adjacent to an actinic keratosis.

Johansson, Hanna

2014-01-01

183

The National Library of Medicine: 175 Years of Innovation | NIH MedlinePlus the Magazine  

MedlinePLUS

... this page please turn Javascript on. The National Library of Medicine 175 Years of Information Innovation Past ... than 40 years! Today, thanks to the National Library of Medicine, virtually any bit of information ever ...

184

49 CFR 175.310 - Transportation of flammable liquid fuel; aircraft only means of transportation.  

Code of Federal Regulations, 2010 CFR

...Transportation of flammable liquid fuel; aircraft only means of transportation. 175...HAZARDOUS MATERIALS REGULATIONS CARRIAGE BY AIRCRAFT Specific Regulations Applicable According...Transportation of flammable liquid fuel; aircraft only means of transportation....

2010-10-01

185

40 CFR 408.175 - Standards of performance for new sources.  

Code of Federal Regulations, 2012 CFR

...POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.175...this subpart: (1) Any mechanized salmon processing facility located in population...0 to 9.0. (2) Any mechanized salmon processing facility not covered...

2012-07-01

186

40 CFR 408.175 - Standards of performance for new sources.  

Code of Federal Regulations, 2011 CFR

...POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.175...this subpart: (1) Any mechanized salmon processing facility located in population...0 to 9.0. (2) Any mechanized salmon processing facility not covered...

2011-07-01

187

40 CFR 408.175 - Standards of performance for new sources.  

Code of Federal Regulations, 2010 CFR

...POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.175...this subpart: (1) Any mechanized salmon processing facility located in population...0 to 9.0. (2) Any mechanized salmon processing facility not covered...

2010-07-01

188

26 CFR 1.175-1 - Soil and water conservation expenditures; in general.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Soil and water conservation expenditures; in general... § 1.175-1 Soil and water conservation expenditures; in general...farmer may deduct his soil or water conservation expenditures which...

2009-04-01

189

26 CFR 1.175-1 - Soil and water conservation expenditures; in general.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Soil and water conservation expenditures; in general... § 1.175-1 Soil and water conservation expenditures; in general...farmer may deduct his soil or water conservation expenditures which...

2010-04-01

190

26 CFR 1.175-1 - Soil and water conservation expenditures; in general.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Soil and water conservation expenditures; in general... § 1.175-1 Soil and water conservation expenditures; in general...farmer may deduct his soil or water conservation expenditures which...

2013-04-01

191

21 CFR 175.360 - Vinylidene chloride copolymer coatings for nylon film.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Vinylidene chloride copolymer coatings for nylon film. ...of Coatings § 175.360 Vinylidene chloride copolymer coatings for nylon film. Vinylidene chloride copolymer coatings identified in...

2013-04-01

192

STUDIES OF MOLECULAR CLOUDS ASSOCIATED WITH H II REGIONS: S175  

SciTech Connect

We are studying the impact of H II regions on star formation in their associated molecular clouds. In this paper, we present James Clerk Maxwell Telescope R x A molecular line observations of S175 and environs. This is the first within a sample of 10 H II regions and their surrounding molecular clouds selected for our study. We first make 7' x 7' maps in {sup 12}CO(2-1), which are used to investigate the structure of the cloud and to identify individual clumps. Single point observations were made in {sup 13}CO(2-1) and CS(5-4) at the peak of the {sup 12}CO(2-1) emission within each clump in order to measure the physical properties of the gas. Densities, temperatures, clump masses, peak velocities, and line widths were measured and calculated using these observations. We have identified two condensations (S175A and S175B) in the molecular cloud associated with this H II region. S175A is adjacent to the ionization front and is expected to be affected by the H II region, while S175B is too distant to be disturbed. We compare the structure and gas properties of these two regions to investigate how the molecular gas has been affected by the H II region. S175A has been heated by the H II region and partially compressed by the ionized gas front, but contrary to our expectation it is a quiescent region while S175B is very turbulent and dynamically active. Our investigation for the source of turbulence in S175B resulted in the detection of an outflow within this region.

Azimlu, Mohaddesseh; Fich, Michel; McCoey, Carolyn [Department of Physics and Astronomy, University of Waterloo, Waterloo, ON N2L 3G1 (Canada)

2009-06-15

193

25 CFR 224.175 - How will rescission affect valid existing rights or lawful actions taken before the rescission?  

Code of Federal Regulations, 2011 CFR

...224.175 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS TRIBAL ENERGY RESOURCE AGREEMENTS UNDER THE INDIAN TRIBAL ENERGY DEVELOPMENT AND SELF DETERMINATION ACT Rescission § 224.175 How...

2011-04-01

194

The World Leader in Health Information and Innovation Celebrates 175 Years | NIH MedlinePlus the Magazine  

MedlinePLUS

... turn Javascript on. Feature: NLM 175th Anniversary The World Leader in Health Information and Innovation Celebrates 175 ... the National Library of Medicine (NLM) is the world's largest biomedical library. With some 14 million items ...

195

Un nouveau cristal laser largement accordable le BOYS dopé à l'ytterbium  

NASA Astrophysics Data System (ADS)

Nous avons étudié les performances laser en pompage par diode de puissance d'un nouveau cristal : le Sr3Y(BO3)3 (acronyme : BOYS), dopé à l'ytterbium. Son spectre d'émission particulièrement large en fait un matériau particulièrement prometteur pour la réalisation de lasers femtosecondes directement pompés par diode. Ses performances ont été comparées à celles d'un verre phosphate ainsi qu'à celles du cristal d' Yb:GdCOB dans les mêmes conditions. Nous démontrons que, tant du point de vue de l'efficacité laser que de la tenue aux fortes puissances, GdCOB et BOYS sont supérieurs au verre ; le BOYS est de surcroît plus accordable (sur 50 nm), mais son comportement thermique limite a priori son usage à des puissances de pompe modérées.

Chénais, S.; Druon, F.; Balembois, F.; Georges, P.; Gaumé, R.; Aka, G.; Viana, B.; Vivien, D.

2002-06-01

196

Optical excitation and decay dynamics of ytterbium atoms embedded in solid neon matrix  

NASA Astrophysics Data System (ADS)

We have studied the optical excitation and decay dynamics of neutral ytterbium atoms embedded in cryogenic solid neon. The embedded atoms qualitatively retain the structure and transition property of free atoms in the gas phase. The transitions are shifted by and broadened to typically a few hundred cm-1. The broadening mechanism is found to be homogeneous. Atomic population can be transferred among the internal levels via resonant optical excitation and spontaneous decay. The rates of intercombination transitions between spin-singlet and spin-triplet levels are vastly enhanced, probably due to strong Stark-induced mixing. However, the 6s6p 3P0 level is found to remain metastable, with its lifetime determined to be 14 s for the odd isotopes and a few minutes for the even isotopes. This work is supported by DOE, Office of Nuclear Physics, under contract DEAC02-06CH11357.

Xu, Chen-Yu; Hu, Shuiming; Bailey, Kevin; Lu, Zheng-Tian; Mueller, Peter; O'Connor, Thomas; Singh, Jaideep

2011-06-01

197

Towards optical pumping of ytterbium nuclei embedded in a solid neon matrix  

NASA Astrophysics Data System (ADS)

We have studied the optical excitation and decay dynamics of neutral ytterbium atoms embedded in a cryogenic solid neon matrix. Matrix isolated atoms qualitatively retain the energy level structure of atoms in the gas phase. The transitions are typically blue shifted and significantly broadened to a few hundred cm-1, independent of temperature from 2.6 K to 4.2 K. The transition width is found to be homogeneous but not lifetime broadened. We will report our results on spectroscopy, lifetimes, and our attempt to polarize nuclear spins by optical pumping. Applications of such a technique include studies of rare isotopes and tests of fundamental symmetries. This work is supported by DOE, Office of Nuclear Physics, under contract DEAC02-06CH11357.

Xu, Chen-Yu; Singh, Jaideep; Bailey, Kevin; Lu, Zheng-Tian; Mueller, Peter; O'Connor, Thomas

2012-06-01

198

8-Quinolinolate complexes of yttrium and ytterbium: molecular arrangement and fragmentation under laser impact.  

PubMed

New 8-quinolinolate (Q) complexes of yttrium (1) and ytterbium (2) were synthesized by the reactions of Cp3Y and Yb[N(SiMe3)2]3 with 3 equiv. of 8-hydroxyquinoline in a DME solution. Single crystal X-ray analysis revealed the trinuclear molecular structure of the compounds Ln3Q9. The LDI-TOFMS investigation displayed that under the laser impact the compounds split off Q(-) anions to give Ln3Q8(+), Ln2Q5(+) and LnQ3(+) moieties. In the negative mode spectra the anions Q(-) and LnQ4(-) were observed. The DFT calculations showed the decreased stability of cationic Ln-quinolinolate as compared with their anionic counterparts. Complex 2 which is used as an emitter in a three-layer OLED displayed a metal-centered emission at 979 nm and an intensity of 50 ?W cm(-2) at 15.5 V. PMID:24048370

Baranov, Evgeny V; Fukin, Georgy K; Balashova, Tatyana V; Pushkarev, Anatoly P; Grishin, Ivan D; Bochkarev, Mikhail N

2013-11-28

199

Power-dependent loss from an ytterbium magneto-optic trap  

NASA Astrophysics Data System (ADS)

Radiative decay of excited 1P1 states to metastables is expected to limit attainable lifetimes in magneto-optic traps (MOTs) containing alkaline-earth-metal-like atoms. We present measurements of power-dependent loss from a (6s2)1S0- (6s6p)1P1 ytterbium MOT, show that the observed power dependence is consistent with radiative decay from the (6s6p)1P1 excited state leading to population of lower-lying metastable states, and determine the (6s6p)1P1-to-metastable state decay rate. With weak excitation of the (6s2)1S0- (6s6p)1P1 trapping transition, MOT lifetimes approaching 800 ms are observed.

Loftus, T.; Bochinski, J. R.; Shivitz, R.; Mossberg, T. W.

2000-05-01

200

Improved setup and procedure for benchmarking of photodarkening in ytterbium doped silica fibers  

NASA Astrophysics Data System (ADS)

This paper presents a new setup and a corresponding procedure for the accurate measurement of photodarkening in ytterbium doped fibers. The core-pumping scheme enables the use of short samples and a low pump power and the automation of the measurement permits long-term tests for an effective benchmarking of fibers with low photo-degradation. Exploiting temperature-controlled components and coherent detection, this arrangement allows the measurement of transmission drops below 2% over hundreds of hours. For the first time, a long-term photodarkening experiment (up to 450 h) has been carried out and correlated to the drop in output power experienced by a laser using the same type of fiber, demonstrating that the system can be employed in pre-compliance testing of active fibers prior to their use in a laser configuration.

Olivero, M.; Braglia, A.; Perrone, G.; Boetti, N. G.; Lousteau, J.; Milanese, D.

2012-12-01

201

Bis(pentamethylcyclopentadienyl)ytterbium: An investigation of weak interactions in solution using multinuclear NMR spectroscopy  

SciTech Connect

NMR spectroscopy is ideal for studying weak interactions (formation enthalpy {le}20 kcal/mol) in solution. The metallocene bis(pentamethylcyclopentadienyl)ytterbium, Cp*{sub 2}Yb, is ideal for this purpose. cis-P{sub 2}PtH{sub 2}complexes (P = phosphine) were used to produce slow-exchange Cp*{sub 2}YbL adducts for NMR study. Reversible formation of (P{sub 2}PtH){sub 2} complexes from cis-P{sub 2}PtH{sub 2} complexes were also studied, followed by interactions of Cp*{sub 2}Yb with phosphines, R{sub 3}PX complexes. A NMR study was done on the interactions of Cp*{sub 2}Yb with H{sub 2}, CH{sub 4}, Xe, CO, silanes, stannanes, C{sub 6}H{sub 6}, and toluene.

Schwartz, D.J.

1995-07-01

202

Coherent combination of two ytterbium fiber amplifier based on an active segmented mirror  

NASA Astrophysics Data System (ADS)

To control the phase noise of two ytterbium fiber amplifiers, a coherent combination system based on an active segmented mirror (ASM) has been established in our laboratory. The ASM is controlled by a feed back control loop on the basis of a Peak Rate (PR) algorithm which is realized on a DSP + FPGA hardware control board. Experimental results indicate that when the control loop is off, the far-field interference pattern is blurred and dynamic, while when it is on, the far-field beams interference pattern achieves clear and stable. At two different output powers, the contrasts of the interference stripes are improved from 7% to 19% and 8% to 28% respectively.

Yang, Ping; Yang, Ruofu; Shen, Feng; Li, Xinyang; Jiang, Wenhan

2009-04-01

203

Arc fusion splicing effects in large-mode-area single-mode ytterbium-doped fibers.  

PubMed

For the first time the effects of arc fusion splicing on the residual stress and refractive index of large-mode-area single-mode ytterbium-doped fibers (YDFs) are investigated using a state-of-the-art three-dimensional concurrent stress-index measurement method. The results, based on a commercially available fiber, describe a host of perturbations that decrease the core/cladding refractive index difference by as much as 1.74 × 10(-3) over an axial length of many hundreds of wavelengths. Simulations indicate that these perturbations result in an expansion of the mode-field-diameter by 39.6% and, based on the measured sample, result in an extra splice loss of 20.8%. The results of this investigation will be useful in the design and optimization of high-power all-fiber YDF lasers and amplifiers. PMID:24216728

Feng, Ting; Jenkins, Micah H; Yan, Fengping; Gaylord, Thomas K

2013-11-10

204

Ytterbium-Doped Yettrium Aluminum Garnet Crystal Fiber Multipass Ring Laser  

NASA Astrophysics Data System (ADS)

We report the growth of ytterbium-doped yettrium aluminum garnet (Yb:YAG) crystal fibers by the laser-heated pedestal growth (LHPG) method. The characteristics of Yb:YAG crystal fibers were analyzed by electron probe microanalyzer (EPMA) and X-ray diffraction measurements. The small crystal fiber diameter makes it effective for heat removal from a high-Yb3+-concentration and quasi-three-level gain medium. The length of this crystal-fiber-based high absorption can be shorter, which is eminently suitable for a multipass ring cavity to maintain cavity stability and mode symmetry. We successfully demonstrated a two-mirror multipass ring laser with 54.7% slope efficiency, which is higher than the 50.3% for a bulk Yb:YAG laser.

Yi, Jui-Yun; Huang, Kuang-Yao; Lai, Chien-Chih; Peng, Hsin; Chen, Li-Hsuan; Huang, Sheng-Lung

2010-12-01

205

Erbium-ytterbium doped fiber amplifier with suppressed Yb-ASE and improved efficiency  

NASA Astrophysics Data System (ADS)

A new design of an erbium-ytterbium doped fiber amplifier is demonstrated. The amplifier contains a wavelength-tuned loop resonator for the 1 ?m signal. The amplified spontaneous emission (ASE) from Yb ions is used to stimulate a laser emission at several wavelengths from the 1 ?m band in the 1550 nm amplifier. The wavelength of this lasing is selected by introducing a spectral filter. The results show, that the efficiency of the amplifier at nominal 1550 nm wavelength can be increased by introducing a feedback loop with 1040 nm and 1050 nm filters. This loop also protects the Er-Yb amplifier from parasitic lasing and allows output power scaling without risk of self-pulsing at 1 ?m.

Sobon, Grzegorz; Sliwinska, Dorota; Kaczmarek, Pawel; Abramski, Krzysztof M.

2013-01-01

206

146W continuous wave ytterbium doped fiber amplifier at 1009 nm  

NASA Astrophysics Data System (ADS)

In this contribution we demonstrate a single mode continuous wave laser amplifier with 146 W of power at a wavelength of 1009 nm. On one hand this experiments constitutes an extension of the wavelength range of high power fiber lasers, furthermore, emission wavelength well below 1030 nm find use for efficient high-brightness tandem pumping of high power fiber amplifiers. The wavelength and bandwidth of the seed oscillator are defined by a pair of fiber Bragg gratings. This seed is amplified in a two-stage Ytterbium-doped rod-type amplifier to 146 W with a high slope efficiency of 64 %, an excellent beam quality and an ASE-suppression as high as 63 dB.

Beier, F.; Otto, H.-J.; Sattler, B.; Ploetner, M.; Haarlammert, N.; de Vries, O.; Jauregui, C.; Schreiber, T.; Limpert, J.; Eberhardt, R.; Tünnermann, A.

2014-03-01

207

Lifetime reduction due to photodarkening phenomenon in ytterbium-doped fibers and rate equation term.  

PubMed

In this Letter, the lifetime temporal reduction in ytterbium-doped aluminosilicate fibers due to pump-induced photodarkening (PD) has been reported. A linear correlation between lifetime reduction at equilibrium state and equilibrium losses due to the PD phenomenon was demonstrated. A squared-law dependence between lifetime reduction and dopant concentration (percent by weight) suggests a possible correction term for the rate equations system which allows improving its accuracy. Finally, a quenching effect was also observed for different pump power levels in order to find the corresponding lifetime value for different inversion levels. The quantitative analysis allows determination of the PD quenching term in the laser rate equations system to properly model a laser device that may be affected by this process. PMID:24177096

Piccoli, Riccardo; Mechin, David; Robin, Thierry; Taccheo, Stefano

2013-11-01

208

The dawn of computer-assisted robotic osteotomy with ytterbium-doped fiber laser.  

PubMed

Currently, laser radiation is used routinely in medical applications. For infrared lasers, bone ablation and the healing process have been reported, but no laser systems are established and applied in clinical bone surgery. Furthermore, industrial laser applications utilize computer and robot assistance; medical laser radiations are still mostly conducted manually nowadays. The purpose of this study was to compare the histological appearance of bone ablation and healing response in rabbit radial bone osteotomy created by surgical saw and ytterbium-doped fiber laser controlled by a computer with use of nitrogen surface cooling spray. An Ytterbium (Yb)-doped fiber laser at a wavelength of 1,070 nm was guided by a computer-aided robotic system, with a spot size of 100 ?m at a distance of approximately 80 mm from the surface. The output power of the laser was 60 W at the scanning speed of 20 mm/s scan using continuous wave system with nitrogen spray level 0.5 MPa (energy density, 3.8 × 10(4) W/cm(2)). Rabbits radial bone osteotomy was performed by an Yb-doped fiber laser and a surgical saw. Additionally, histological analyses of the osteotomy site were performed on day 0 and day 21. Yb-doped fiber laser osteotomy revealed a remarkable cutting efficiency. There were little signs of tissue damage to the muscle. Lased specimens have shown no delayed healing compared with the saw osteotomies. Computer-assisted robotic osteotomy with Yb-doped fiber laser was able to perform. In rabbit model, laser-induced osteotomy defects, compared to those by surgical saw, exhibited no delayed healing response. PMID:24241973

Sotsuka, Yohei; Nishimoto, Soh; Tsumano, Tomoko; Kawai, Kenichiro; Ishise, Hisako; Kakibuchi, Masao; Shimokita, Ryo; Yamauchi, Taisuke; Okihara, Shin-ichiro

2014-05-01

209

Single-frequency ytterbium-doped fiber laser at 976 nm  

NASA Astrophysics Data System (ADS)

Linearly polarized wavelength stable single frequency ytterbium (Yb3+) doped fiber lasers below 1 ?m, namely threelevel Yb3+ fiber lasers, are highly demanded for nonlinear wavelength conversion to generate coherent blue light or even deep ultraviolet coherent sources. We present performance of a 976 nm single-frequency core-pumped distributed Bragg reflector (DBR) fiber laser consisting of a 2-cm long highly ytterbium-doped phosphate fiber and a pair of silica fiber Bragg gratings (FBGs) and their use for frequency doubling experiment. The high reflection (HR > 99%) and partial reflection (PR = 60%) FBGs were cleaved very close to the index modulation region and directly spliced to a 2-cm-long highly Yb3+-doped phosphate fiber. Over 100 mW of linearly polarized output with a linewidth less than 2 kHz can be obtained when the launched pump power is about 450 mW. The efficiency of the 976 nm single-frequency fiber laser (the output power vs the launched pump power) is about 25%. The relative intensity noise was measured to be -110 dB/Hz at 1 MHz and the variation of the center wavelength is less than 0.0005 nm during a measurement period of 2.5 hours. This single-frequency fiber laser has an SNR of over 50 dB and there is no strong ASE or spurious lasing at long wavelengths even at the maximum pump power. This all-fiber single-frequency DBR laser with attractive features can be used for efficient blue and UV generation through nonlinear frequency conversion. Moreover, this high-performance 976 nm single-frequency fiber laser can be used as a single-frequency, low RIN pump laser for long wavelength Yb3+-, Er3+-, or Yb3+/Er3+-doped fiber lasers and amplifiers.

Zhu, X.; Shi, W.; Zong, J.; Nguyen, D.; Norwood, R. A.; Chavez-Pirson, A.; Peyghambarian, N.

2013-02-01

210

Creation of quantum-degenerate gases of ytterbium in a compact 2D-/3D-magneto-optical trap setup  

NASA Astrophysics Data System (ADS)

We report on the first experimental setup based on a 2D-/3D-magneto-optical trap (MOT) scheme to create both Bose-Einstein condensates and degenerate Fermi gases of several ytterbium isotopes. Our setup does not require a Zeeman slower and offers the flexibility to simultaneously produce ultracold samples of other atomic species. Furthermore, the extraordinary optical access favors future experiments in optical lattices. A 2D-MOT on the strong 1S0 --> 1P1 transition captures ytterbium directly from a dispenser of atoms and loads a 3D-MOT on the narrow 1S0 --> 3P1 intercombination transition. Subsequently, atoms are transferred to a crossed optical dipole trap and cooled evaporatively to quantum degeneracy.

Dörscher, Sören; Thobe, Alexander; Hundt, Bastian; Kochanke, André; Le Targat, Rodolphe; Windpassinger, Patrick; Becker, Christoph; Sengstock, Klaus

2013-04-01

211

Low-high season variation in Plasmodium falciparum erythrocyte binding antigen 175 (eba-175) allelic forms in malaria endemic area of Burkina Faso  

PubMed Central

Summary Objective To assess the impact of seasonal variation on the distribution of the eba-175 allelic forms in the area where malaria transmission is markedly seasonal. Methods Blood samples were collected from 291 and 239 children under five years of age during the low and the high malaria transmission season, respectively, in four villages named Dawelgué, Kounda, Tanghin and Watenga of Saponé Health District, then screened for eba 175 F- and C- alleles by nested PCR analysis. Results F- alleles were more prevalent than C-alleles in the low [0.66 versus 0.34 (p<0.0001)] and high transmission season [0.67. versus 0.33(p<0.0001)]. No significant seasonal variation was observed in the distribution of the two alleles. However, according to Sewall Wright rules, the population pairwise FST values, between Dawelgué and Tanghin during the low transmission season (FST_ value= 0.10415, p-value= 0.0090 and during the high season (FST_value= 0.08244, p-value?0.00001), between Tanghin and Watenga during the low season (FST value=0.07414, p-value=0.009) indicated a moderate but statistically significant genetic differentiation. Conclusion Although there was a moderate but significant genetic differentiation between some study villages at different times of the year, this study result in the seasonal stability of eba-175 allele’s distribution in the study area.

Soulama, Issiaka; Bougouma, Edith C.; Diarra, Amidou; Nebie, Issa; Sirima, Sodiomon B.

2010-01-01

212

Reconstitution of {beta}-carotene hydroxylase activity of thermostable CYP175A1 monooxygenase  

SciTech Connect

CYP175A1 is a thermostable P450 Monooxygenase from Thermus thermophilus HB27, demonstrating in vivo activity towards {beta}-carotene. Activity of CYP175A1 was reconstituted in vitro using artificial electron transport proteins. First results were obtained in the mixture with a crude Escherichia coli cell extract at 37 {sup o}C. In this system, {beta}-carotene was hydroxylated to {beta}-cryptoxanthin. The result indicated the presence of electron transport enzymes among the E. coli proteins, which are suitable for CYP175A1. However, upon in vitro reconstitution of CYP175A1 activity with purified recombinant flavodoxin and flavodoxin reductase from E. coli, only very low {beta}-cryptoxanthin production was observed. Remarkably, with another artificial electron transport system, putidaredoxin and putidaredoxin reductase from Pseudomonas putida, purified CYP175A1 enzyme hydroxylated {beta}-carotene at 3- and also 3'-positions, resulting in {beta}-cryptoxanthin and zeaxanthin. Under the optimal reaction conditions, the turnover rate of the enzyme reached 0.23 nmol {beta}-cryptoxanthin produced per nmol P450 per min.

Momoi, Kyoko [Institute of Technical Biochemistry, University of Stuttgart, Stuttgart 70569 (Germany); Hofmann, Ute [Dr. Margarete Fischer-Bosch-Institut fuer Klinische Pharmakologie, Stuttgart 70376 (Germany); Schmid, Rolf D. [Institute of Technical Biochemistry, University of Stuttgart, Stuttgart 70569 (Germany); Urlacher, Vlada B. [Institute of Technical Biochemistry, University of Stuttgart, Stuttgart 70569 (Germany)]. E-mail: itbvkha@po.uni-stuttgart.de

2006-01-06

213

A new approach to prepare nanoscopic rare earth metal fluorides: the fluorolytic sol-gel synthesis of ytterbium fluoride.  

PubMed

A new approach for the preparation of approx. 5 nm sized ytterbium fluoride nanoparticles based on the fluorolytic sol-gel route is reported. DLS, TEM, IR and XRD were used to characterize the particles as well as the aging behavior of the sols. Furthermore, a new Yb(III) complex was isolated from the precursor solution and characterized by X-ray single crystal structure determination. PMID:24824632

Schmidt, L; Dimitrov, A; Kemnitz, E

2014-06-25

214

High-energy femtosecond pulses from an ytterbium-doped fiber laser with a new cavity design  

Microsoft Academic Search

A new architecture which is based on the chirped pulse amplification scheme is proposed to increase the pulse energy of the mode-locked fiber laser. The idea was applied to a passively mode-locked laser using an ytterbium (Yb3+)-doped double-clad silica fiber. Mode-locking was achieved by nonlinear polarization evolution associated to frequency-shifted feedback technique for self-starting. A compressor and a stretcher, based

A. Albert; V. Couderc; L. Lefort; A. Barthelemy

2004-01-01

215

The effect of ytterbium fluoride and barium sulphate nanoparticles on the reactivity and strength of a glass-ionomer cement  

Microsoft Academic Search

ObjectivesWhile clinical advantages of glass-ionomers include fluoride release and radiopacity, disadvantages include low strength, slow initial setting times and opacity. The addition of nanoparticles, in particular those containing fluoride and cross-linkable ions, may mitigate the disadvantages while further improving the advantages. This investigation evaluated the effects of the addition of ytterbium fluoride (YbF3) and barium sulphate (BaSO4) on the strength

Leon H. Prentice; Martin J. Tyas; Michael F. Burrow

2006-01-01

216

Continuously Tunable Chirped Microwave Waveform Generation Using a Tilted Fiber Bragg Grating Written in an Erbium\\/Ytterbium Codoped Fiber  

Microsoft Academic Search

An optical approach to generating continuously tunable chirped microwave waveforms using a tilted fiber Bragg grating (TFBG) written in an erbium\\/ytterbium (Er\\/Yb) codoped fiber is proposed. By pumping the TFBG, the magnitude and group delay responses of the cladding mode resonances are changed, which can be used to implement a photonic microwave delay-line filter with increasing or decreasing tap spacing.

Hiva Shahoei; Jianping Yao

2012-01-01

217

Studies on CW and Q-switched mode-locked in passive mode-locked ytterbium-doped fibre laser  

Microsoft Academic Search

Exploiting the nonlinear polarization rotation technique and adjusting the polarization controllers orientations and the pump\\u000a power, we achieved stable operations of Q-switched mode-locked or CW modelocked regimes in an ytterbium-doped fibre laser\\u000a with a unidirectional ring cavity containing a polarizer placed between two in-line polarization controllers. Numerical simulations\\u000a of pulse propagation in such a modelocked fibre ring laser are performed,

Y. Gan; W. H. Xiang; G. Z. Zhang

2009-01-01

218

Studies on CW and Q-switched mode-locked in passive mode-locked ytterbium-doped fibre laser  

Microsoft Academic Search

Exploiting the nonlinear polarization rotation technique and adjusting the polarization controllers orientations and the pump power, we achieved stable operations of Q-switched mode-locked or CW modelocked regimes in an ytterbium-doped fibre laser with a unidirectional ring cavity containing a polarizer placed between two in-line polarization controllers. Numerical simulations of pulse propagation in such a modelocked fibre ring laser are performed,

Y. Gan; W. H. Xiang; G. Z. Zhang

2009-01-01

219

Dosimetric characteristics, air-kerma strength calibration and verification of Monte Carlo simulation for a new ytterbium-169 brachytherapy source  

Microsoft Academic Search

Ytterbium-169 ([sup 169]Yb) is a promising new isotope for brachytherapy with a half life of 32 days and an average photon energy of 93 KeV. It has an Ir-192-equivalent dose distribution in water but a much smaller half-value layer in lead (0.2 mm), affording improved radiation protection and customized shielding of dose-limiting anatomic structures. The goals of this study are

Harold Perera; Jeffrey F Williamson; Zuofeng Li; Vivek Mishra; Ali S Meigooni

1994-01-01

220

Monte Carlo characterization of an ytterbium-169 high dose rate brachytherapy source with analysis of statistical uncertainty  

Microsoft Academic Search

An ytterbium-169 high dose rate brachytherapy source, distinguished by an intensity-weighted average photon energy of 92.7 keV and a 32.015{+-}0.009 day half-life, is characterized in terms of the updated AAPM Task Group Report No. 43 specifications using the MCNP5 Monte Carlo computer code. In accordance with these specifications, the investigation included Monte Carlo simulations both in water and air with

John J. Munro; Mark A. Tries; David C. Medich

2006-01-01

221

Spectrally narrowed amplified spontaneous emission source at 977 nm based on a single-mode ytterbium-doped fiber  

Microsoft Academic Search

We present an amplified spontaneous emission (ASE) source based on a single-mode ytterbium-doped fiber pumped by a Nd : YVO4 laser emitting at 914 nm. The ASE is centered on 977 nm with a bandwidth of 3 nm. With a spectrally filtered reflection of the copropagating ASE, we have obtained a source of ASE with a bandwidth of 0.4 nm

A. Bouchier; G. Lucas-Leclin; F. Balembois; P. Georges

2004-01-01

222

Narrow-linewidth ytterbium-doped fiber amplifier system with 45 nm tuning range and 133 W of output power.  

PubMed

We report on a master-oscillator ytterbium-doped fiber amplifier system with up to 133 W of continuous-wave output power using a tunable narrow-linewidth external-cavity diode laser seed source. Stable tunable high-power operation was demonstrated from 1040 nm to 1085 nm with more than 12 dB suppression of amplified spontaneous emission. PMID:17700780

Hildebrandt, M; Frede, M; Kracht, D

2007-08-15

223

Complete elimination of self-pulsations in dual-clad ytterbium-doped fiber lasers at all pumping levels.  

PubMed

We have demonstrated suppression and elimination of self-pulsing in a watt-level, dual-clad, ytterbium-doped fiber laser. The addition of a long section of passive fiber in the laser cavity makes the gain recovery faster than the self-pulsation dynamics, allowing only stable cw lasing. This scheme provides a simple and practical method for eliminating self-pulsations in fiber lasers at all pumping levels. PMID:19282942

Guan, W; Marciante, J R

2009-03-15

224

High-power and tunable operation of erbium-ytterbium co-doped cladding-pumped fiber lasers  

Microsoft Academic Search

We describe erbium-ytterbium co-doped fiber lasers in different free-running and tunable configurations. The lasers were cladding-pumped by high-power multimode diode sources. We compare pumping at 915 and 980 nm. With a free-running laser, we obtained slope efficiencies of up to 50% with 915-nm pumping and 38% with 980-nm pumping, with respect to absorbed pump power. We reached a double-ended output

Johan Nilsson; Shaif-Ul Alam; Jose A. Alvarez-Chavez; Paul W. Turner; W. Andrew Clarkson; Anatoly B. Grudinin

2003-01-01

225

Antibodies to Plasmodium Falciparum Erythrocyte Binding Antigen-175 are Associated with Protection from Clinical Malaria  

PubMed Central

Background Antibodies to blood-stage Plasmodium falciparum antigens have been associated with protection against clinical malaria in some studies but not others. Many of these studies have not assessed whether high-titer antibodies are associated with protection and have not adjusted for differences in malaria exposure. Methods The presence of high-titer antibodies to apical membrane antigen-1 (AMA-1), erythrocyte binding antigen-175 (EBA-175) and merozoite surface protein-119 (MSP-119) was assessed in 87 children living in a malaria holoendemic area of Kenya. The children were prospectively assessed during one year for clinical malaria. Results In unadjusted analyses, high-titer antibodies to MSP-119, but not EBA-175 or AMA-1, were associated with protection from clinical malaria. However, after adjustment for exposure, only high-titer antibodies to EBA-175 were associated with protection from clinical malaria (hazard ratio (HR), 0.48, 95% confidence interval (CI) 0.24, 0.95, P=0.03), and with reduced episodes of clinical malaria (incidence rate ratio, 0.50, 95 % CI, 0.31, 0.81, P=0.005). A trend toward increased protection from clinical malaria in children was seen with antibodies to both EBA-175 and MSP-119 (HR, 0.26, 95% CI 0.03, 1.94, P=0.18) Conclusions High-titer antibodies to EBA-175 are associated with protection from clinical malaria in children in a malaria holoendemic area of Kenya. Accurate estimates of antibody-associated protection from clinical malaria require adjustment for malaria exposure.

MCCARRA, MATTHEW B.; AYODO, GEORGE; SUMBA, PETER O.; KAZURA, JAMES W.; MOORMANN, ANN M.; NARUM, DAVID L.; JOHN, CHANDY C.

2011-01-01

226

Improved cycling behavior of ZEBRA battery operated at intermediate temperature of 175°C  

SciTech Connect

Operation of the sodium-nickel chloride battery at temperatures below 200°C reduces cell degradation and improves cyclability. One of the main technical issues with operating this battery at intermediate temperatures such as 175°C is the poor wettability of molten sodium on ?”-alumina solid electrolyte (BASE), which causes reduced active area and limits charging. In order to overcome the poor wettability of molten sodium on BASE at 175°C, a Pt grid was applied on the anode side of the BASE using a screen printing technique. Cells with their active area increased by metallized BASEs exhibited deeper charging and stable cycling behavior.

Li, Guosheng; Lu, Xiaochuan; Kim, Jin Yong; Lemmon, John P.; Sprenkle, Vincent L.

2014-01-01

227

CCD observations of Abell clusters. V - Isophotometry of 175 brightest elliptical galaxies in Abell clusters  

Microsoft Academic Search

Profiles of major- and minor-axis surface brightness, ellipticity, position angle, and isophote centroid are presently derived from isophotometry for a sample of 175 brightest cluster ellipticals (BCEs). The BCEs' average ellipticity is a sharply rising function of metric radius; less than a fourth of the sample exhibits significant ellipticity decrease with increasing radius. While at radii of less than 16

Alain C. Porter; Donald P. Schneider; John G. Hoessel

1991-01-01

228

175. Photocopy of photograph, U.S. Army, ca. 1943 (original print ...  

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

175. Photocopy of photograph, U.S. Army, ca. 1943 (original print located at Rocky Mountain Arsenal, Commerce City, Colorado). R.M.A. - 626 - POST ENGINEER LOOKING N.W. - Rocky Mountain Arsenal, Bounded by Ninety-sixth Avenue & Fifty-sixth Avenue, Buckley Road, Quebec Street & Colorado Highway 2, Commerce City, Adams County, CO

229

46 CFR 7.175 - Alaska Peninsula, AK to Nunivak, AK.  

Code of Federal Regulations, 2013 CFR

...LINES Alaska § 7.175 Alaska Peninsula, AK to Nunivak, AK. (a) A line drawn from the northernmost extremity of Goose Point at Egegik Bay to Protection Point. (b) A line drawn from the westernmost extremity of Kulukak Point to the...

2013-10-01

230

25 CFR 175.61 - Appeals to the Interior Board of Indian Appeals.  

Code of Federal Regulations, 2011 CFR

...43 CFR part 4, subpart D, except that a notice of appeal from a decision under § 175.12 shall be filed within 30 days of publication of the decision. The address for the Interior Board of Indian Appeals shall be included in the operations manual....

2011-04-01

231

Random mutagenesis of bacterial luciferase: critical role of Glu175 in the control of luminescence decay  

PubMed Central

Bacterial luciferases (LuxAB) can be readily classed as slow or fast decay luciferases based on their rates of luminescence decay in a single turnover assay. Luciferases from Vibrio harveyi and Xenorhabdus (Photorhabdus) luminescens have slow decay rates, and those from the Photobacterium genus, such as Photobacterium fisheri, P. phosphoreum and P. leiognathi, have rapid decay rates. By substitution of a 67-amino-acid stretch of P. phosphoreum LuxA in the central region of the LuxA subunit, the ‘slow’ X. luminescens luciferase was converted into a chimaeric luciferase with a significantly more rapid decay rate [Valkova, Szittner and Meighen (1999) Biochemistry 38, 13820–13828]. To understand better the role of specific residues in the classification of luciferases as slow and fast decay, we have conducted random mutagenesis on this region. One of the mutants generated by a single mutation on LuxA at position 175 [E175G (Glu175?Gly)] resulted in the ‘slow decay’ X. luminescens luciferase being converted into a luciferase with a significantly more rapid decay rate. These results indicate the importance of Glu175 in LuxA as a critical residue for differentiating between ‘slow’ and ‘fast’ luciferases and show that this distinction is primarily due to differences in aldehyde affinity and in the decomposition of the luciferase–flavin–oxygen intermediate.

2004-01-01

232

Signature Splitting in 7/2 [633]v band of 175Hf  

NASA Astrophysics Data System (ADS)

In this paper, we present an explanation of signature splitting observed in the one quasiparticle rotational band (7/2[633]?) of 175Hf in terms of one particle plus rotor model (PRM) calculations. The role of angular momentum dependence of the inertia parameter and rotational correction term appearing in Coriolis mixing calculations to explain signature effects is discussed.

Singh, Jagjit; Kumar, Sushil; Goel, A.; Sharma, J. K.; Singh, Sukhjeet

2014-03-01

233

36 CFR 1192.175 - High-speed rail cars, monorails and systems.  

Code of Federal Regulations, 2013 CFR

... 2012-07-01 true High-speed rail cars, monorails and systems. 1192...and Systems § 1192.175 High-speed rail cars, monorails and systems. (a) All cars for high-speed rail systems, including but not limited to...

2013-07-01

234

miR-17-5p promotes proliferation by targeting SOCS6 in gastric cancer cells.  

PubMed

This study aimed to test the exact functions and potential mechanisms of miR-17-5p in gastric cancer. Using real-time PCR, miR-17-5p was found to be expressed more highly in gastric cancer compared with-normal tissues. Gain- and loss-of-function assays demonstrated that miR-17-5p increased the proliferation and growth of gastric cancer cells in vitro and in vivo. Through reporter gene and western blot assays, SOCS6 was shown to be a direct target of miR-17-5p, and proliferative assays confirmed that SOCS6 exerted opposing function to that of miR-17-5p in gastric cancer. In short, miR-17-5p might function as a pro-proliferative factor by repressing SOCS6 in gastric cancer. PMID:24801601

Wu, Qiong; Luo, Guanhong; Yang, Zhiping; Zhu, Fei; An, Yanxin; Shi, Yongquan; Fan, Daiming

2014-06-01

235

Role of ytterbium and ytterbium/cesium fluoride on the chemistry of poly(9,9-dioctylfluorene-co-benzothiadiazole) as investigated by photoemission spectroscopy  

NASA Astrophysics Data System (ADS)

Since ytterbium (Yb) possesses a low work function of 2.6 eV and Yb fluoride generally has a high negative free energy of formation, it is conceivable to use Yb, either directly or parasitically, with a metal fluoride, as a cathode in organic light-emitting diodes (OLEDs). In this work, the electronic structure and chemistry at the interface of Yb/poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) were investigated by ultraviolet and x-ray photoemission spectroscopy (UPS and XPS, respectively). We found that the deposition of Yb on top of F8BT foremost formed organometallic complexes with the sulfur but interacted partly with the nitrogen of F8BT, and eventually formed a Yb-C complex at higher Yb coverages. In the UPS spectra, Yb deposition increased the relative peak intensities corresponding to the ?-bonds originated from the aliphatic side chains, implying that some of the ?-conjugated carbons in the polymer backbone may be destroyed. These results agree well with the disappearance of the ?-to-?* transition as observed from the shake-up peaks of the carbon 1s core level in the XPS. The chemistry at the interfaces of Yb/CsF/Au and Yb/CsF/F8BT was also examined by XPS. In both cases, Cs was liberated from the CsF upon Yb deposition and the Yb reacted with the liberated F to form YbF3. In the Yb/CsF/F8BT system, the dissociated Cs did not exist in the metallic state, but reacted with the N atoms and carbon backbone in the F8BT. The low work function of Cs (2.2 eV) may further enhance the injection of electrons into the polymer layer. More importantly, the utilization of Yb/CsF as an electrode is polymer independent, and the CsF layer between the Yb and F8BT could retard Yb diffusion into the bulk polymer. The present results are supported by a calculation of the free energy needed to liberate the Cs in the metal/CsF system using a simple thermodynamic model. It is suggested that the use of Yb/CsF cathode in the polymer offers an advantage over most other metal fluorides because the current electrode has a higher affinity to liberate Cs due to the high negative heat of formation of YbF3, although Yb alone may not be a good electron injector in OLEDs.

Fung, M. K.; Tong, S. W.; Lai, S. L.; Bao, S. N.; Lee, C. S.; Wu, W. W.; Inbasekaran, M.; O'Brien, J. J.; Liu, S. Y.; Lee, S. T.

2003-08-01

236

Microstructure and electrical properties of thin films of ReSi 1.75 produced by co-sputtering  

Microsoft Academic Search

Microstructural evolution and changes in electrical resistivity of ReSi1.75 thin films produced by co-sputtering has been investigated as a function of annealing temperature. Crystallization of amorphous ReSi1.75 thin films occurs at 600 °C without forming any metastable phases. The crystallization temperature for ReSi1.75 is considerably higher than those observed for other transition-metal disilicides. The crystal structure as well as the domain

Kosuke Kuwabara; Haruyuki Inui; Masaharu Yamaguchi

2002-01-01

237

The cytoplasmic domain of the Plasmodium falciparum ligand EBA175 is essential for invasion but not protein trafficking  

Microsoft Academic Search

he invasion of host cells by the malaria parasite Plasmodium falciparum requires specific protein-pro- tein interactions between parasite and host receptors and an intracellular translocation machinery to power the process. The transmembrane erythrocyte binding protein- 175 (EBA-175) and thrombospondin-related anonymous protein (TRAP) play central roles in this process. EBA-175 binds to glycophorin A on human erythrocytes during the invasion process,

Tim-Wolf Gilberger; Jennifer K. Thompson; Michael B. Reed; Robert T. Good; Alan F. Cowman

2003-01-01

238

Degradation of mutant p53H175 protein by Zn(II) through autophagy.  

PubMed

TP53, one of the most important oncosuppressors, is frequently mutated in cancer. Several p53 mutant proteins escape proteolytic degradation and are highly expressed in an aberrant conformation often acquiring pro-oncogenic activities that promote tumor progression and resistance to therapy. Therefore, it has been vastly proposed that reactivation of wild-type (wt) function(s) from mutant p53 (mutp53) may have therapeutic significance. We have previously reported that Zn(II) restores a folded conformation from mutp53 misfolding, rescuing wild-type (wt) p53/DNA-binding and transcription activities. However, whether Zn(II) affects mutp53 stability has never been investigated. Here we show that a novel Zn(II) compound induced mutp53 (R175H) protein degradation through autophagy, the proteolytic machinery specifically devoted to clearing misfolded proteins. Accordingly, pharmacological or genetic inhibition of autophagy prevented Zn(II)-mediated mutp53H175 degradation as well as the ability of the Zn(II) compound to restore wtp53 DNA-binding and transcription activity from this mutant. By contrast, inhibition of the proteasome failed to do so, suggesting that autophagy is the main route for p53H175 degradation. Mechanistically, Zn(II) restored the wtp53 ability to induce the expression of the p53 target gene DRAM (damage-regulated autophagy modulator), a key regulator of autophagy, leading to autophagic induction. Accordingly, inhibition of wtp53 transactivation by pifithrin-? (PFT-?) impaired both autophagy and mutp53H175 degradation induced by curcumin-based zinc compound (Zn(II)-curc). Viewed together, our results uncover a novel mechanism employed by Zn(II)-curc to reactivate mutp53H175, which involves, at least in part, induction of mutp53 degradation via wtp53-mediated autophagy. PMID:24874727

Garufi, A; Pucci, D; D'Orazi, V; Cirone, M; Bossi, G; Avantaggiati, M L; D'Orazi, G

2014-01-01

239

Degradation of mutant p53H175 protein by Zn(II) through autophagy  

PubMed Central

TP53, one of the most important oncosuppressors, is frequently mutated in cancer. Several p53 mutant proteins escape proteolytic degradation and are highly expressed in an aberrant conformation often acquiring pro-oncogenic activities that promote tumor progression and resistance to therapy. Therefore, it has been vastly proposed that reactivation of wild-type (wt) function(s) from mutant p53 (mutp53) may have therapeutic significance. We have previously reported that Zn(II) restores a folded conformation from mutp53 misfolding, rescuing wild-type (wt) p53/DNA-binding and transcription activities. However, whether Zn(II) affects mutp53 stability has never been investigated. Here we show that a novel Zn(II) compound induced mutp53 (R175H) protein degradation through autophagy, the proteolytic machinery specifically devoted to clearing misfolded proteins. Accordingly, pharmacological or genetic inhibition of autophagy prevented Zn(II)-mediated mutp53H175 degradation as well as the ability of the Zn(II) compound to restore wtp53 DNA-binding and transcription activity from this mutant. By contrast, inhibition of the proteasome failed to do so, suggesting that autophagy is the main route for p53H175 degradation. Mechanistically, Zn(II) restored the wtp53 ability to induce the expression of the p53 target gene DRAM (damage-regulated autophagy modulator), a key regulator of autophagy, leading to autophagic induction. Accordingly, inhibition of wtp53 transactivation by pifithrin-? (PFT-?) impaired both autophagy and mutp53H175 degradation induced by curcumin-based zinc compound (Zn(II)-curc). Viewed together, our results uncover a novel mechanism employed by Zn(II)-curc to reactivate mutp53H175, which involves, at least in part, induction of mutp53 degradation via wtp53-mediated autophagy.

Garufi, A; Pucci, D; D'Orazi, V; Cirone, M; Bossi, G; Avantaggiati, M L; D'Orazi, G

2014-01-01

240

Thermal Characteristics of an Ytterbium-Doped Fiber Amplifier Operating at 1060 and 1080 nm  

NASA Astrophysics Data System (ADS)

We experimentally analyze the temperature dependence of an ytterbium-doped fiber amplifier (YDFA) operating at 1060 and 1080 nm, investigating its spectroscopic characteristics and gain properties in the temperature range of 10 to 100 °C. Our measurement indicates that the change in the operating temperature can give rise to a significant effect on the YDFA performance, which also significantly depends on the operating wavelength. At the output power level of approximately 1.5 W, the temperature change from 10 to 100 °C resulted in a signal power drop of approximately 16% at 1060 nm and 5% at 1080 nm, respectively. While this is due mainly to the temperature-dependent spectroscopic characteristics of the gain fiber, it also depends on the input signal and pump power levels. We numerically model this behavior, based on the given experimental conditions and measured fiber parameters. Our numerical results are in good agreement with the experimental results and further suggest that higher seed power to the amplifier should help in minimizing the temperature dependence of the YDFA.

Luis Alonso Vazquez-Zuniga,; Seunghwan Chung,; Yoonchan Jeong,

2010-02-01

241

Hydration of gas-phase ytterbium ion complexes studied by experiment and theory  

SciTech Connect

Hydration of ytterbium (III) halide/hydroxide ions produced by electrospray ionization was studied in a quadrupole ion trap mass spectrometer and by density functional theory (DFT). Gas-phase YbX{sub 2}{sup +} and YbX(OH){sup +} (X = OH, Cl, Br, or I) were found to coordinate from one to four water molecules, depending on the ion residence time in the trap. From the time dependence of the hydration steps, relative reaction rates were obtained. It was determined that the second hydration was faster than both the first and third hydrations, and the fourth hydration was the slowest; this ordering reflects a combination of insufficient degrees of freedom for cooling the hot monohydrate ion and decreasing binding energies with increasing hydration number. Hydration energetics and hydrate structures were computed using two approaches of DFT. The relativistic scalar ZORA approach was used with the PBE functional and all-electron TZ2P basis sets; the B3LYP functional was used with the Stuttgart relativistic small-core ANO/ECP basis sets. The parallel experimental and computational results illuminate fundamental aspects of hydration of f-element ion complexes. The experimental observations - kinetics and extent of hydration - are discussed in relationship to the computed structures and energetics of the hydrates. The absence of pentahydrates is in accord with the DFT results, which indicate that the lowest energy structures have the fifth water molecule in the second shell.

Rutkowski, Philip X; Michelini, Maria C.; Bray, Travis H.; Russo, Nino; Marcalo, Joaquim; Gibson, John K.

2011-02-11

242

Flux Growth of Yb6.6Ir6Sn16 Having Mixed-Valent Ytterbium.  

PubMed

The compound Yb6.6Ir6Sn16 was obtained as single crystals in high yield from the reaction of Yb with Ir and Sn run in excess indium. Single-crystal X-ray diffraction analysis shows that Yb6.6Ir6Sn16 crystallizes in the tetragonal space group P42/nmc with a = b = 9.7105(7) Å and c = 13.7183(11) Å. The crystal structure is composed of a [Ir6Sn16] polyanionic network with cages in which the Yb atoms are embedded. The Yb sublattice features extensive vacancies on one crystallographic site. Magnetic susceptibility measurements on single crystals indicate Curie-Weiss law behavior <100 K with no magnetic ordering down to 2 K. The magnetic moment within the linear region (<100 K) is 3.21 ?B/Yb, which is ?70% of the expected value for a free Yb(3+) ion suggesting the presence of mixed-valent ytterbium atoms. X-ray absorption near edge spectroscopy confirms that Yb6.6Ir6Sn16 exhibits mixed valence. Resistivity and heat capacity measurements for Yb6.6Ir6Sn16 indicate non-Fermi liquid metallic behavior. PMID:24921221

Peter, Sebastian C; Subbarao, Udumula; Rayaprol, Sudhindra; Martin, Joshua B; Balasubramanian, Mahalingam; Malliakas, Christos D; Kanatzidis, Mercouri G

2014-07-01

243

Gamma-radiation-induced degradation of actively pumped single-mode ytterbium-doped optical fibers  

NASA Astrophysics Data System (ADS)

The integration of optical components into the digital processing units of satellite subsystems has the potential to remove interconnect bottlenecks inherent to the volume, mass, complexity, reliability and crosstalk issues of copper-based interconnects. Assuming on-board high-bandwidth communications will utilize passive optical fibers as a communication channel, this work investigates the impact of gamma irradiation from a Co-60 source on both passive optical fibers and ytterbium-doped single-mode fibers operated as amplifiers for a 1060-nm light source. Standard optical patch cables were evaluated along with active Yb-doped double-clad fibers. Varied exposure times and signal transmission wavelengths were used to investigate the degradation of the fibers exposed to total doses above 100 krad (Si). The effect on the amplified signal gain was studied for the Yb-doped fibers. The increased attenuation in the fibers across a broad wavelength range in response to multiple levels of gamma radiation exposure along with the effect that the increased attenuation has on the actively pumped Yb-doped fiber amplifier performance, is discussed.

Singleton, B.; Petrosky, J.; Pochet, M.; Usechak, N. G.; Francis, S. A.

2014-03-01

244

Double-clad fiber amplifier for broadband tunable ytterbium-doped oxyorthosilicates lasers.  

PubMed

Broadband tunable continuous-wave laser action and double-clad fiber amplifier of Yb:GSO, Yb:GYSO and Yb:LYSO crystals have been demonstrated. Under 940 nm diode pump, the free-running Yb:GSO, Yb:GYSO and Yb:LYSO lasers output power are 3.1 W at 1091 nm, 3.0 W at 1083 nm and 1.1 W at 1058 nm, with the corresponding optical-to-optical conversion efficiency of 57%, 42% and 13%, respectively. By using intra-cavity dispersion prism and a slit to restrict the spatial mode structure, continuously tunable range extends from 1002 to 1120 nm, covering some specific wavelengths as required for metrological or optical pumping applications. By using an ytterbium-doped double-clad fiber amplifier, several watts were obtained at tunable wavelengths. Particularly, the output power was 6.5 W for Yb:GSO, 12 W for Yb:GYSO, and 4 W for Yb:LYSO at 1083 nm, which matched the atomic transition wavelength useful for optical pumping of helium. PMID:19550963

Hao, Qiang; Li, Wenxue; Zeng, Heping

2007-12-10

245

All-fiber Q-switched ytterbium-doped fiber laser in MOPA configurations  

NASA Astrophysics Data System (ADS)

An all fiber Q-switched Ytterbium-Doped Fiber "YDF" laser in Master Oscillator Power-Amplifier (MOPA) configuration is proposed theoretically and demonstrated experimentally, and the principle analysis and experimental verification are presented in details. Firstly, the system configuration is designed. The system is composed of the seed and the amplifier stage. Two 915nm LDs are used for pumping light, and the light is coupled into the gain medium of the seed and the amplifier stage by two combiners, respectively. Two Fiber Bragg Gratings (FBGs) are used as ends of the cavity of the seed. One Q-switch is used to modulate output laser of the seed, and the amplifier stage is adopted to amplify the light behind the seed. Then, 10m YDF with single mode is selected for the gain medium of the seed, and 8m YDF with multimode is used as the gain medium of the amplifier stage. The output laser of the seed with a 1.02W average power is realized when the seed pump power is 5.74W, the repetition rate is 20KHz and the action time of the Q-switch is 3.5?s. Meanwhile, a 7.58W pump power of the amplifier stage is used to amplify the seed laser. Finally, output laser with the pulse width of 90ns and the average output power of 4.93W are achieved.

He, Wei; Zhu, Lianqing; Zhang, Yinmin; Dong, Mingli; Chen, Xiaohuai

2013-10-01

246

41 CFR 102-74.175 - Are Government-leased buildings required to conform with the policies in this subpart?  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Are Government-leased buildings required to conform with the policies in this subpart? 102-74.175 Section...102-74.175 Are Government-leased buildings required to conform with the policies in this subpart? Yes, all new...

2010-07-01

247

41 CFR 102-74.175 - Are Government-leased buildings required to conform with the policies in this subpart?  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Are Government-leased buildings required to conform with the policies in this subpart? 102-74.175 Section...102-74.175 Are Government-leased buildings required to conform with the policies in this subpart? Yes, all new...

2009-07-01

248

25 CFR 175.12 - Procedures for adjusting electric power rates except for adjustments due to changes in the cost...  

Code of Federal Regulations, 2011 CFR

...changes in the cost of purchased power or energy. 175.12 Section 175.12 Indians...changes in the cost of purchased power or energy. Except for adjustments to rates due to changes in the cost of purchased power or energy, the Area Director shall adjust...

2011-04-01

249

25 CFR 175.13 - Procedures for adjusting electric power rates to reflect changes in the cost of purchased power...  

Code of Federal Regulations, 2011 CFR

...reflect changes in the cost of purchased power or energy. 175.13 Section 175.13 Indians...reflect changes in the cost of purchased power or energy. Whenever the cost of purchased power or energy changes, the effect of the change on...

2011-04-01

250

49 CFR 175.702 - Separation distance requirements for packages containing Class 7 (radioactive) materials in cargo...  

Code of Federal Regulations, 2013 CFR

...Class 7 (radioactive) materials in cargo aircraft. 175.702 Section 175.702 Transportation...HAZARDOUS MATERIALS REGULATIONS CARRIAGE BY AIRCRAFT Specific Regulations Applicable According...Class 7 (radioactive) materials in cargo aircraft. (a) No person may carry in a...

2013-10-01

251

Note: Broadly tunable all-fiber ytterbium laser with 0.05 nm spectral width based on multimode interference filter  

NASA Astrophysics Data System (ADS)

A multimode interference filter with narrow transmission bandwidth and large self-imaging wavelength interval is constructed and implemented in an ytterbium doped fiber laser in all-fiber format for broad wavelength tunability as well as narrow spectral width of the output beam. The peak transmission wavelength of the multimode interference filter was tuned with the help of a standard in-fiber polarization controller. With this simple mechanism more than 30 nm (1038 nm-1070 nm) tuning range is demonstrated. The spectral width of the output beam from the laser was measured to be 0.05 nm.

Mukhopadhyay, Pranab K.; Gupta, Pradeep K.; Singh, Amarjeet; Sharma, Sunil K.; Bindra, Kushvinder S.; Oak, Shrikant M.

2014-05-01

252

Optimization of the high repetition rate all-fiber two-stage ytterbium-doped fiber amplifier  

NASA Astrophysics Data System (ADS)

Based on the technique of master oscillator power amplifier (MOPA), a two-stage ytterbium-doped fiber amplifier (YDFA) with all-fiber structure is theoretically simulated. The seed signal operating at the wavelength of 1064 nm has the characteristic of high repetition rate (10 MHz), ultrashort pulse duration (10 ps), low signal power input (20?W) and single longitudinal mode. The gain (and amplification stimulation emission power) is calculated at the different pump powers and gain fiber lengths of YDFA pumped by 975 nm. In addition, the amplifications at the different signal power inputs (1-25?W) are also simulated. The numerical results can be used to optimize the YDFA.

Yun, Jian; Gao, Cunxiao; Zhu, Shaolan; Sun, Chuandong; Dong, Lijun

2011-11-01

253

Experimental evidence for the formation of divalent ytterbium in the photodarkening process of Yb-doped fiber lasers.  

PubMed

In this work we present experimental evidence that the valence instability of the ytterbium ion play a key role for the observed photodarkening mechanism in Yb-doped fiber lasers. Luminescence and excitation spectroscopy performed on UV irradiated Yb/Al doped silica glass preforms and near-infrared diode pumped photodarkened fibers show a concentration increase of Yb(2+) ions. A concentration decrease in Yb(3+) could also be observed for the UV irradiated preform. The findings contribute to an increased understanding of the kinetic processes related to photodarkening in Yb-doped high power fiber lasers. PMID:23546049

Rydberg, S; Engholm, M

2013-03-25

254

Composite chromium and graphene oxide as saturable absorber in ytterbium-doped Q-switched fiber lasers.  

PubMed

In recent years, graphene and its compounds (e.g., oxides) have been used as saturable absorbers in passive Q-switched and mode-locked lasers, leading to the fabrication of compact pulsed fiber lasers. In this article, we study the operation of a Q-switched ytterbium-doped fiber ring laser based on a composite saturable absorber made of graphene oxide and chromium. We show that the addition of a thin layer of chromium can lead to pulse durations ranging from 3.5 to 9.4 ?s and subsequently increasing the laser peak power. PMID:24663318

Liu, Liming; Hattori, Haroldo T; Mironov, Evgeny G; Khaleque, Abdul

2014-02-20

255

Note: Broadly tunable all-fiber ytterbium laser with 0.05 nm spectral width based on multimode interference filter.  

PubMed

A multimode interference filter with narrow transmission bandwidth and large self-imaging wavelength interval is constructed and implemented in an ytterbium doped fiber laser in all-fiber format for broad wavelength tunability as well as narrow spectral width of the output beam. The peak transmission wavelength of the multimode interference filter was tuned with the help of a standard in-fiber polarization controller. With this simple mechanism more than 30 nm (1038 nm-1070 nm) tuning range is demonstrated. The spectral width of the output beam from the laser was measured to be 0.05 nm. PMID:24880426

Mukhopadhyay, Pranab K; Gupta, Pradeep K; Singh, Amarjeet; Sharma, Sunil K; Bindra, Kushvinder S; Oak, Shrikant M

2014-05-01

256

Some physical properties of ReSi 1.75 single crystals  

Microsoft Academic Search

We investigated the electronic transport properties and the magnetic susceptibility of the semiconducting silicide ReSi1.75. This compound crystallises in a monoclinic structure (space group P1). The resistivity of this silicide is anisotropic depending on the direction of the current flow. At high temperatures we observe thermally activated behaviour for the resistivity with one (or two) energy gap(s) Eg = 0.16

U. Gottlieb; M. Affronte; F. Nava; O. Laborde; A. Sulpice; R Madar

1995-01-01

257

Hadron-nucleus elastic scattering at 70, 125, and 175 GeV/c  

SciTech Connect

Hadron-nucleus elastic scattering is measured for ..pi../sup + -/, K/sup + -/, p, and p-bar scattering from Be, C, Al, Cu, Sn, and Pb targets at incident beam momenta of 70 and 175 GeV/c and for ..pi../sup +/, K/sup +/, and p scattering from Be, Al, and Pb targets at an incident beam momentum of 125 GeV/c. Parametrizations of dsigma/dt in the forward direction for the reactions are presented.

Schiz, A.; Fajardo, L.A.; Majka, R.; Marx, J.N.; Nemethy, P.; Rosselet, L.; Sandweiss, J.; Slaughter, A.J.; Ankenbrandt, C.; Atac, M.; Brown, R.; Ecklund, s.; Gollon, a.J.; Lach, J.; MacLachlan, J.; Roberts, A.; Shen, G.

1980-06-01

258

Hadron-nucleus elastic scattering at 70, 125, and 175 GeV\\/c  

Microsoft Academic Search

Hadron-nucleus elastic scattering is measured for pi+\\/-, K+\\/-, p, and p¯ scattering from Be, C, Al, Cu, Sn, and Pb targets at incident beam momenta of 70 and 175 GeV\\/c and for pi+, K+, and p scattering from Be, Al, and Pb targets at an incident beam momentum of 125 GeV\\/c. Parametrizations of d sigmadt in the forward direction for

A. Schiz; L. A. Fajardo; R. Majka; J. N. Marx; P. Némethy; L. Rosselet; J. Sandweiss; A. J. Slaughter; C. Ankenbrandt; M. Atac; R. Brown; S. Ecklund; P. J. Gollon; J. Lach; J. MacLachlan; A. Roberts; G. Shen

1980-01-01

259

17.5um thin Cu wire bonding for fragile low-K wafer technology  

Microsoft Academic Search

This paper describes the challenges of a 17.5um thin bare Cu wire bonding on aluminum bond pads for a fragile low-k wafer technology, on a BGA package. Previous evaluations have so far focused on 20um and 25um bare Cu wires as a suitable low cost replacement for Au wires. To improve performance, more fragile low-k wafer technology is being developed.

Teo Chen; Kim Jude

2010-01-01

260

Precision measurement of the hyperfine structure of Lu 175 with the atomic beam magnetic resonance method  

Microsoft Academic Search

The hyperfine structure separations of both doublet states2D3\\/2 and2D5\\/2 of the ground state configuration 6s2 5d of Lu175 have been remeasured with high precision using the atomic beam magnetic resonance method. Magnetic dipole transitions between Zeeman components of the hfs levels were induced applying Ramsey's technique of separated oscillatory fields whenever the field dependence of the resonances was small enough.

H. Figger; G. Wolber

1973-01-01

261

Structure of YAG crystals doped/substituted with erbium and ytterbium.  

PubMed

Two series of yttrium aluminum garnets doped with erbium and ytterbium ions have been studied by single-crystal X-ray diffraction. The single crystals were obtained by the Czochralski method. The concentration of doping ions was established by the plasma emission spectroscopy method. For the Er series, it is equal to 23.4, 46.7, 72.5, and 100%, whereas, for Yb-doped YAGs, it equals 26.5, 48.2, 75.9, and 100%. The results are supplemented by the data obtained for pure YAG. The X-ray data for all samples were collected at two temperatures: 295(2) and 102(2) K. Additionally, for YAGs doped with ca. 50% of doping ions, some more detailed temperature measurements were performed. Pure single crystals of ErAG and YbAG were also studied as a function of diffraction angles. Careful single-crystal measurements utilizing a CCD diffractometer revealed the unit cell parameters, which slightly-but significantly-deviate from cubic symmetry. The average unit cell parameters change linearly with the amount of substituting Er and Yb cations, with two different slopes related to the ionic radii. Both of the dodecahedral distances depend linearly on the concentration of the substituting ions, but the longer dodecahedral distance also changes with temperature contrary to the shorter one. There is no correlation between the octahedral interatomic distance [Al(VI)...O] and the unit cell parameter or temperature; however, weak trends appear for the tetrahedral [Al(IV)...O] distance. Such weak trends are just the secondary consequences of the ion substitution taking place at the dodecahedral site. The dependences between the unit cell parameters and the concentration of doping ions allow us to establish concentrations of particular doping ions in mixed (Er, Yb) doped YAGs just on the basis of the measured unit cell parameters and knowledge of the amount of Y. PMID:15554630

Dobrzycki, Lukasz; Bulska, Ewa; Pawlak, Dorota Anna; Frukacz, Zygmunt; Wo?niak, Krzysztof

2004-11-29

262

NIR luminescence and catalysis of multifarious salen type ytterbium complexes modulated by anions.  

PubMed

A series of five N,N'-bis(2-hydroxy-3-methoxybenzylidene)-1,3-propanediamine (H2L) ytterbium complexes, namely, [Yb(H2L)2(CH3OH)](ClO4)3 (1), [Yb(H2L)(NO3)3]2·CH2Cl2 (2), [Yb(H2L)2(NO3)]2(PF6)4·4H2O·2CH2Cl2 (3), [Yb(H2L)(OAc)2]2(PF6)2·4CH2Cl2 (4) and [Yb3L'3(OH)2Cl(H2O)5]Cl3·4H2O (5) (HL' = 2-hydroxy-3-methoxybenzaldehyde), have been synthesized by reactions of H2L with multifarious Yb(iii) salts. X-ray diffraction analysis reveals that complex 1 shows a unique mononuclear structure constructed from two chelating H2L ligands in crossover mode. Complex 2 exhibits a dinuclear structure bridged by two H2L ligands. Complexes 3 and 4 possess two novel dinuclear structures linked by NO3(-) and OAc(-) anions, respectively. Complex 5 displays a trinuclear structure supported by three L' and two OH(-) anions. Noticeable, complex 3 can be transformed from 2 by introducing (NH4)(PF6). The PF6(-) counterion plays an essential role in steering the structural transformation. The anions dominate the final structures of 1-5. All complexes 1-5 exhibit NIR luminescence, which can be rationalized on the basis of different structural effects. Preliminary catalytic studies reveal that all complexes 1-5 are able to catalyze effectively a typical Henry reaction with good yields. PMID:23884178

Zou, Xiaoyan; Yan, Pengfei; Zhang, Juwen; Zhang, Fengming; Hou, Guangfeng; Li, Guangming

2013-09-28

263

Covalency in the 4f shell of tris-cyclopentadienyl ytterbium (YbCp3)--a spectroscopic evaluation.  

PubMed

Evidence is presented of significant covalency in the ytterbium 4f shell of tris-cyclopentadienyl ytterbium (YbCp(3)) in its electronic ground state, that can be represented by the superposition of an ionic configuration Yb(III):4f(13)(Cp(3)) and a charge-transfer configuration Yb(II):4f(14)(Cp(3))(-1). The relative weights of these configurations were determined from (i) the difference in their 4f photoionization cross sections, (ii) the accumulation of spin-density centered on the (13)C atoms of the Cp ring, as measured by a pulsed EPR (HYSCORE) experiment, (iii) the reduction in the spin-density in the 4f shell, manifest in the (171)Yb hyperfine interaction, and (iv) the principal values of the g-tensor, obtained from the EPR spectrum of a frozen glass solution at 5.4 K. Each of these methods finds that the spin density attributable to the charge transfer configuration is in the range 12-17%. The presence of configuration interaction (CI) also accounts for the highly anomalous energies, intensities, and vibronic structure in the "f-f" region of the optical spectrum, as well as the strict adherence of the magnetic susceptibility to the Curie law in the range 30-300 K. PMID:22053917

Denning, Robert G; Harmer, Jeffrey; Green, Jennifer C; Irwin, Mark

2011-12-21

264

Vibrational spectra of lutetium and ytterbium bis-phthalocyanine in thin solid films and SER(R)S on silver island films  

NASA Astrophysics Data System (ADS)

Thin solid films of lutetium and ytterbium diphthalocyanine (Pc 2) complexes have been studied using vibrational and electronic absorptions, spontaneous and resonant Raman (RR) and surface enhanced Raman scattering (SERS) on silver island films. Surface enhanced resonance Raman spectra (SERRS) are identical to the RRS spectra with an enhancement factor of about 500. Vibrational data were consistent with a C4 v molecular symmetry.

Aroca, R.; Clavijo, R. E.; Jennings, C. A.; Kovacs, G. J.; Duff, J. M.; Loutfy, R. O.

1989-01-01

265

Role of pump duration on temperature and efficiency of up-conversion in fluoride crystals co-doped with ytterbium and thulium  

Microsoft Academic Search

Pump pulse duration is shown to determine the maximum efficiency of the up conversion process in ytterbium, thulium co-doped fluoride crystals through its role in determining the emitter temperature reached. We show that up-conversion efficiencies should only be measured when using the same pumping conditions as would be used in a proposed application and that thermal management of the up

Alexandra Rapaport; Janet Milliez; Michael Bass; Arlete Cassanho; Hans Jenssen

2004-01-01

266

TEST RESULTS OF THE LANL 350 MHZ, BETA=0.175, 2-GAP SPOKE RESONATOR.  

SciTech Connect

Two 350-MHz ? = 0.175 two-gap superconducting (SC) spoke resonator cavities have been fabricated in industry under an R&D project for the Advanced Accelerator Applications (AAA) program at LANL. This paper describes the structure, presents the test results of mechanical properties, tuning sensitivity at room temperature, and Q- E curves at 4 K. A maximum accelerating field of 11.6 MV/m has been obtained, which exceeds our present goal of 7.5 MV/m with ample margin

Tajima, Tsuyoshi; Gentzlinger, Robert C.; Roybal, Ray J.; Krawczyk, Frank L.; Schrage, Dale L.; Ledford, John; Montoya, Debbie I.; Shapiro, Alan H.; Barni, Danilo; Bissotti, Angelo; Pagani, Carlo

2002-08-16

267

Allelic dimorphism of the erythocyte binding antigen-175 (eba-175) gene of Plasmodium falciparum and severe malaria: Significant association of the C-segment with fatal outcome in Ghanaian children  

Microsoft Academic Search

BACKGROUND: The erythrocyte binding antigen-175 (EBA-175) on Plasmodium falciparum merozoites mediates sialic acid dependent binding to glycophorin A on host erythrocytes and, therefore, plays a crucial role in cell invasion. Dimorphic allele segments have been found in its encoding gene with a 342 bp segment present in FCR-3 strains (F-segment) and a 423 bp segment in CAMP strains (C-segment). Possible

Jakob P Cramer; Frank P Mockenhaupt; Ingo Möhl; Sabine Dittrich; Ekkehardt Dietz; Rowland N Otchwemah; Stephan Ehrhardt; Ulrich Bienzle; Tomas Jelinek

2004-01-01

268

42 CFR 84.175 - Half-mask facepieces, full facepieces, hoods, helmets, and mouthpieces; fit; minimum requirements.  

Code of Federal Regulations, 2012 CFR

... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Non-Powered Air-Purifying Particulate Respirators § 84.175 Half-mask facepieces, full facepieces, hoods, helmets, and...

2012-10-01

269

41 CFR 102-85.175 - Are the standard level services for cleaning, mechanical operation, and maintenance identified in...  

Code of Federal Regulations, 2010 CFR

...false Are the standard level services for cleaning, mechanical operation...175 Are the standard level services for cleaning, mechanical operation...in the OA, standard level services for cleaning, mechanical...

2010-07-01

270

41 CFR 102-85.175 - Are the standard level services for cleaning, mechanical operation, and maintenance identified in...  

Code of Federal Regulations, 2010 CFR

...false Are the standard level services for cleaning, mechanical operation...175 Are the standard level services for cleaning, mechanical operation...in the OA, standard level services for cleaning, mechanical...

2009-07-01

271

20 CFR 411.175 - What if a continuing disability review is begun before my ticket is in use?  

Code of Federal Regulations, 2013 CFR

... Section 411.175 Employees' Benefits SOCIAL SECURITY ADMINISTRATION THE TICKET TO WORK AND SELF-SUFFICIENCY PROGRAM Suspension...VR agency acting as an EN under the Ticket to Work program, or you may still receive...

2013-04-01

272

40 CFR 723.175 - Chemical substances used in or for the manufacture or processing of instant photographic and peel...  

Code of Federal Regulations, 2010 CFR

...manufacture or processing of instant photographic and peel-apart film articles. 723.175...2604). (8) The term instant photographic film article means a self-developing...identify and describe the instant photographic film article(s) or...

2009-07-01

273

40 CFR 723.175 - Chemical substances used in or for the manufacture or processing of instant photographic and peel...  

Code of Federal Regulations, 2010 CFR

...manufacture or processing of instant photographic and peel-apart film articles. 723.175...2604). (8) The term instant photographic film article means a self-developing...identify and describe the instant photographic film article(s) or...

2010-07-01

274

41 CFR 102-33.175 - What standards must we establish or require (contractually, where applicable) to train our flight...  

Code of Federal Regulations, 2013 CFR

...contractually, where applicable) to train our flight program personnel? 102-33.175...contractually, where applicable) to train our flight program personnel? You must establish...an instructional program to train your flight program personnel, initially and...

2013-07-01

275

46 CFR 175.118 - Vessels operating under an exemption afforded in the Passenger Vessel Safety Act of 1993 (PVSA).  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Vessels operating under an exemption afforded in the Passenger Vessel Safety Act of 1993 (PVSA). 175...SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) GENERAL...

2013-10-01

276

41 CFR 102-85.175 - Are the standard level services for cleaning, mechanical operation, and maintenance identified in...  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Are the standard level services for cleaning, mechanical operation...POLICY FOR OCCUPANCY IN GSA SPACE Standard Levels of Service § 102-85.175 Are the standard level services for cleaning, mechanical...

2013-07-01

277

Some physical properties of ReSi 1.75 single crystals  

NASA Astrophysics Data System (ADS)

We investigated the electronic transport properties and the magnetic susceptibility of the semiconducting silicide ReSi 1.75. This compound crystallises in a monoclinic structure (space group P1). The resistivity of this silicide is anisotropic depending on the direction of the current flow. At high temperatures we observe thermally activated behaviour for the resistivity with one (or two) energy gap(s) Eg = 0.16 eV (0.30 eV). Hall effect measurements yield a positive Hall coefficient in the temperature range between 30 and 660 K. At room temperature we found a Hall carrier concentration of 3.7 × 10 18 cm -3 and a quite high Hall mobility of 370 cm 2/V · s. As the resistivity, the magnetic susceptibility of ReSi 1.75 is anisotropic depending on the orientation of the magnetic field relative to the crystallographic axes. At room temperature ? is strongly diamagnetic. Below about 50 K, ? increases with decreasing temperature.

Gottlieb, U.; Affronte, M.; Nava, F.; Laborde, O.; Sulpice, A.; Madar, R.

1995-10-01

278

Investigation of drum pressurization incident in the 331 Building, Room 175 on January 10, 1995  

SciTech Connect

On January 10, 1995, a pressurized drum incident occurred at the 331 Building, Room 175. On January 12, 1995, the Manager of the Life Sciences Center appointed members to an Investigation Board to investigate the incident (see Exhibit A). This incident was initially categorized as an Off-Normal Occurrence, but was later elevated to an Unusual Occurrence by the Occurrence Classifier. The scope of this investigation was to employ a formal method of root cause analysis, identify the methodology, and report the results of the analysis, fully explaining the technical elements of the causal sequence along with a description of the barriers that should have or could have prevented the occurrence. During the course of the investigation, the scene of the event was not accessible. Therefore, the investigation relied primarily on testimony from staff members directly involved and their management. In addition, other outside professionals were also consulted. The Investigation Board visited the previous location of the drum, 331A Building, Room 9; Room 173, which fronts room 175, was also visited. The Investigation Board reviewed selected documents, which are also listed.

Pollari, R.A.

1995-02-01

279

Delineation of Stage Specific Expression of Plasmodium falciparum EBA175 by Biologically Functional Region II Monoclonal Antibodies  

Microsoft Academic Search

BackgroundThe malaria parasite Plasmodium falciparum EBA-175 binds its receptor sialic acids on glycophorin A when invading erythrocytes. The receptor-binding region (RII) contains two cysteine-rich domains with similar cysteine motifs (F1 and F2). Functional relationships between F1 and F2 domains and characterization of EBA-175 were studied using specific monoclonal antibodies (mAbs) against these domains.Methods and FindingsFive mAbs specific for F1 or

B. Kim Lee Sim; David L. Narum; Rana Chattopadhyay; Adriana Ahumada; J. David Haynes; Steven R. Fuhrmann; Jennifer N. Wingard; Hong Liang; J. Kathleen Moch; Stephen L. Hoffman; Photini Sinnis

2011-01-01

280

Evidence for Two-stage Binding by the 175-kD Erythrocyte Binding Antigen of Plasmodium fa\\/c\\/parum  

Microsoft Academic Search

Summary Plasmodium falciparum malaria merozoites invade human erythrocytes bearing sialic acid in a multistage process involving the sialic acid-dependent binding of a malaria molecule, the 175-kD erythrocyte binding antigen (EBA-175). We show here that after the initial interaction of EBA- 175 with its sialic add-containing erythrocyte determinant, endogenous proteases can cleave EBA-175 to 65-kD fragment(s), whose binding to erythrocytes is

Kevin C. Kain; Palmer A. Orlandi; J. David Haynes; B. Kim; Lee Sim; David E. Lanar

281

Slope efficiency over 30% single-frequency ytterbium-doped fiber laser based on Sagnac loop mirror filter.  

PubMed

A high-slope-efficiency single-frequency (SF) ytterbium-doped fiber laser, based on a Sagnac loop mirror filter (LMF), was demonstrated. It combined a simple linear cavity with a Sagnac LMF that acted as a narrow-bandwidth filter to select the longitudinal modes. And we introduced a polarization controller to restrain the spatial hole burning effect in the linear cavity. The system could operate at a stable SF oscillating at 1064 nm with the obtained maximum output power of 32 mW. The slope efficiency was found to be primarily dependent on the reflectivity of the fiber Bragg grating. The slope efficiency of multi-longitudinal modes was higher than 45%, and the highest slope efficiency of the single longitudinal mode we achieved was 33.8%. The power stability and spectrum stability were <2% and <0.1%, respectively, and the signal-to-noise ratio measured was around 60 dB. PMID:24085181

Yin, Mojuan; Huang, Shenghong; Lu, Baole; Chen, Haowei; Ren, Zhaoyu; Bai, Jintao

2013-09-20

282

Passive mode locking of ytterbium- and erbium-doped all-fiber lasers using graphene oxide saturable absorbers.  

PubMed

Broadband graphene oxide/PVA films were used as saturable absorbers (SAs) for mode locking erbium-doped fiber laser (EDFL) and ytterbium-doped fiber laser (YDFL) at 1.06 ?m and 1.55 ?m. They provide modulation depths of 3.15% and 6.2% for EDFL and YDFL, respectively. Stable self-starting mode-locked pulses are obtained for both lasers, confirming that the graphene oxide is cost-effective. We have generated mode-locked pulses with spectral width, repetition rate, and pulse duration of 0.75 nm, 9.5 MHz, and 2.7 ps. This is the shortest pulse duration directly obtained from an all-normal-dispersion YDFL with graphene-oxide saturable absorber. PMID:24921485

Chen, Hou-Ren; Tsai, Chih-Ya; Cheng, Hsin-Ming; Lin, Kuei-Huei; Hsieh, Wen-Feng

2014-06-01

283

All-optical switching in Sagnac loop mirror containing an ytterbium-doped fiber and fiber Bragg grating.  

PubMed

A configuration of all-optical switching based on a Signac loop mirror that incorporates an ytterbium-doped fiber and uniform fiber Bragg grating (FBG) is proposed in this paper. It is found that the transmission spectrum of this structure is the narrow splitting of the reflection spectrum of the FBG. The shift of this ultranarrow transmission spectrum is very sensitive to the intensity of the pump power. Thus, the threshold switching power can be greatly reduced by shifting such narrow transmission spectrum. Compared with the single FBG, the threshold switching power of this configuration is reduced by 4 orders of magnitude. In addition, the results indicate that this optical switching has a high extinction ratio of 20 dB and a ultrafast response time of 3 ns. The operation regime and switching performance under the cross-phase modulation cases are also investigated. PMID:23938421

Zang, Zhigang

2013-08-10

284

Dual-core ytterbium fiber amplifier for high-power 1060nm swept source multichannel optical coherence tomography imaging  

NASA Astrophysics Data System (ADS)

A novel (to our knowledge) dual-core ytterbium (Yb3+) doped fiber, as an optically pumped amplifier, boosts the output power from a 1060nm swept source laser beyond 250mW, while providing a wavelength tuning range of 93nm, for optical coherence tomography (OCT) imaging. The design of the dual-core Yb-doped fiber amplifier and its multiple wavelength optical pumping scheme to optimize output bandwidth are discussed. Use of the dual-core fiber amplifier showed no appreciable degradation to the coherence length of the seed laser. The signal intensity improvement of this amplifier is demonstrated on a multichannel in vivo OCT imaging system at 1060nm.

Harduar, Mark K.; Mariampillai, Adrian; Vuong, Barry; Gu, Xijia; Standish, Beau A.; Yang, Victor X. D.

2011-08-01

285

Spectral diagnostics of a vapor-plasma plume produced during welding with a high-power ytterbium fiber laser  

NASA Astrophysics Data System (ADS)

We have conducted spectroscopic studies of the welding plasma formed in the process of welding with an ytterbium fiber laser delivering output power of up to 20 kW. The influence of shielding gases (Ar, He) on different parts of the welding plume is investigated. The absorption coefficient of the laser radiation by the welding-plume plasma is estimated. Scattering of 532-nm probe radiation from particles of the condensed metal vapor within the caustic of a high-power fiber laser beam is measured. Based on the obtained results, conclusions are made on the influence of the plasma formation and metal vapor condensation on the radiation of the high-power fiber laser and the stability of the welding process.

Uspenskiy, S. A.; Shcheglov, P. Yu.; Petrovskiy, V. N.; Gumenyuk, A. V.; Rethmeier, M.

2013-07-01

286

Picosecond to femtosecond pulses from high power self mode-locked ytterbium rod-type fiber laser.  

PubMed

We have designed an ytterbium rod-type fiber laser oscillator with tunable pulse duration. This system that delivers more than 10 W of average power is self mode-locked. It yields femtosecond to picosecond laser pulses at a repetition rate of 74 MHz. The pulse duration is adjusted by changing the spectral width of a band pass filter that is inserted in the laser cavity. Using volume Bragg gratings of 0.9 nm and 0.07 nm spectrum bandwidth, this oscillator delivers nearly Fourier limited 2.8 ps and 18.5 ps pulses, respectively. With a 4 nm interference filter, one obtains picosecond pulses that have been externally dechirped down to 130 fs. PMID:23669929

Deslandes, Pierre; Perrin, Mathias; Saby, Julien; Sangla, Damien; Salin, François; Freysz, Eric

2013-05-01

287

High-power nanosecond ytterbium-doped fiber laser passively synchronized with a femtosecond Ti:sapphire laser.  

PubMed

We report on laser synchronization between a high-power nanosecond fiber laser and an ultrashort Ti:sapphire laser by cross-absorption modulation and power amplification. The nanosecond pulses were generated by a long-cavity ytterbium-doped fiber laser that was passively synchronized to a 70 fs Ti:sapphire laser with a remarkable cavity mismatch tolerance of about 8 cm as a result of resonance-enhanced cross-absorption modulation in additional rare-earth-doped fiber. By using a two-stage Yb-doped fiber preamplifier and a two-stage double-clad fiber power amplifier in cascade, the synchronized nanosecond pulses were amplified to 131 W of average power, corresponding to 0.55 mJ of single-pulse energy at a repetition rate of 240 KHz, with a timing jitter of 13 ps. PMID:19881584

Yan, Ming; Li, Wenxue; Hao, Qiang; Li, Yao; Yang, Kangwen; Zhou, Hui; Zeng, Heping

2009-11-01

288

Dual-core ytterbium fiber amplifier for high-power 1060 nm swept source multichannel optical coherence tomography imaging.  

PubMed

A novel (to our knowledge) dual-core ytterbium (Yb(3+)) doped fiber, as an optically pumped amplifier, boosts the output power from a 1060 nm swept source laser beyond 250 mW, while providing a wavelength tuning range of 93 nm, for optical coherence tomography (OCT) imaging. The design of the dual-core Yb-doped fiber amplifier and its multiple wavelength optical pumping scheme to optimize output bandwidth are discussed. Use of the dual-core fiber amplifier showed no appreciable degradation to the coherence length of the seed laser. The signal intensity improvement of this amplifier is demonstrated on a multichannel in vivo OCT imaging system at 1060 nm. PMID:21808377

Harduar, Mark K; Mariampillai, Adrian; Vuong, Barry; Gu, Xijia; Standish, Beau A; Yang, Victor X D

2011-08-01

289

Advanced attenuation and fluorescence measurement methods in the investigation of photodarkening and related properties of ytterbium-doped fibers.  

PubMed

Considering the continuous development of ytterbium (Yb)-doped fibers for fiber lasers and amplifiers, thorough characterization of the features and quality of such fibers is necessary now more than ever. In particular, the evaluation of the very strong core attenuation that results from Yb absorption and the losses accompanying photodarkening (PD) processes in Yb-doped optical fibers is still of immense interest. Keeping that in mind, the potential of a method using pinhole fibers will be demonstrated here. Moreover, the investigation of fluorescence properties of Yb3+ is also important; it can be affected by phenomena such as reabsorption, inhomogeneous pump intensity distribution, amplified spontaneous emission, lasing, and, lastly, PD. As these phenomena occur while measuring the fluorescence properties of Yb3+ in optical fibers, they can distort the fluorescence spectra and fluorescence decay significantly. We suggest a twice-perpendicular measurement method and strict time management to avoid these interfering phenomena during the fluorescence measurements. PMID:24663377

Schwuchow, Anka; Unger, Sonja; Jetschke, Sylvia; Kirchhof, Johannes

2014-03-01

290

Evaluation of anisotropic thermoelectric power of ReSi 1.75  

NASA Astrophysics Data System (ADS)

The highly anisotropic transport properties of ReSi 1.75 single crystals have been evaluated with the Boltzmann transport equation under the assumption that the deformation potential acoustic phonon scattering is dominant. There is a large difference between the calculated transport properties and the measured properties along [1 0 0], while there is little difference between the calculated and the measured along [0 0 1]. The intervalley scattering mechanism is proposed as the reason of the discrepancy in the transport properties along [1 0 0]. It is also shown that the large effective mass of holes along [0 0 1] restrict the contribution of the holes in transporting the energy induced by the Seebeck effect, resulting in good thermoelectric conversion efficiency.

Oh, Min-Wook; Gu, Jia-Jun; Inui, Haruyuki; Oh, Myung-Hoon; Wee, Dang-Moon

2007-02-01

291

[The 175th anniversary of the District Military Clinical Hospital of the Leningrad Military District].  

PubMed

For 175 years a hospital made a great contribution to the development of national health care, gaining a wealth experience in high quality health care for the soldiers. Especially the biggest merit was made by the hospital during the Great Patriotic War of 1941-1945, when 82% of the wounded soldiers ware returned for further service. The hospital was glorified by famous medical scientists of XIX-XX-centuries, such as: V. Bekhterev, R. Wreden, N. Sklifosovsky, P. Kupriyanov, N. Petrov and others. Currently, the hospital takes a worthy place among the best military medical agencies of Russian Armed Forces. The hospital is equipped with modern medical equipment. There work highly qualified personnel: 17 distinguished doctors of the Russian Federation, 2 doctors and 27 candidates of medical sciences. In practice the hospital successfully uses achievements of the leading Russian military medical facilities. The staff treat with care historical traditions of the hospital. PMID:21254531

Liutov, V V

2010-09-01

292

Progressive myoclonus epilepsy EPM1 locus maps to a 175-kb interval in distal 21q  

SciTech Connect

The EPM1 locus responsible for progressive myoclonus epilepsy of Unverricht-Lundborg type (MIM 254800) maps to a region in distal chromosome 21q where positional cloning has been hampered by the lack of physical and genetic mapping resolution. We here report the use of a recently constituted contig of cosmid, BAC, and P1 clones that allowed new polymorphic markers to be positioned. These were typed in 53 unrelated disease families from an isolated Finnish population in which a putative single ancestral EPM1 mutation has segregated for an estimated 100 generations. By thus exploiting historical recombinations in haplotype analysis, EPM1 could be assigned to the {approximately}175-kb interval between the markers D21S2040 and D21S1259. 26 refs., 2 figs., 4 tabs.

Virtaneva, K.; Miao, J.; Traeskelin, A.L.; Chapelle, A. de la; Lehesjoki, A.E. [Univ. of Helsinki (Finland)] [and others

1996-06-01

293

(CaxNd11-x)Ru4O24 (x = 4.175)  

PubMed Central

Single crystals of the title compound, calcium neodymium ruthenate, (CaxNd11-x)Ru4O24 (x = 4.175), have been grown by the flux method. The structure consists of two crystallographically independent RuO6 octa­hedra, which are isolated from each other and embedded in a matrix composed of the Ca and Nd atoms. There are seven M sites which accommodate the Ca and Nd atoms with different populations. Four M sites at general positions are enriched with Nd, whereas the remaining three M sites on twofold rotation axes are enriched with Ca. The coordination numbers of O atoms to the M sites range from 6 to 9. The mean oxidation state of Ru was estimated at +4.79 from the composition analysis. The title compound is non-centrosymmetric and potentially multiferroic.

Sakakura, Terutoshi; Okada, Keita; Iguchi, Hironaga; Wang, Jun; Ishizawa, Nobuo

2010-01-01

294

High throughput RNAi screening identifies ID1 as a synthetic sick/lethal gene interacting with the common TP53 mutation R175H  

PubMed Central

The TP53 mutation (R175H) is one of the most common mutations in human cancer. It is a highly attractive strategy for cancer therapy to find the genes that lead the R175H-expressing cancer cells. The aim of this study was to identify the synthetic sick/lethal gene interacting with R175H. Using lentiviral bar-coded comprehensive shRNA library and a tetracycline-inducible R175H expressed in the SF126 human glioblastoma cell line (SF126-tet-R175H), we conducted high-throughput screening to identify the candidate genes that induce synthetic sickness/lethality in R175H-expressing cells. We identified 906 candidate gene suppressions that may lead to accelerated cell growth inhibition in the presence of R175H. Inhibitor of differentiation 1 (ID1) was one of the candidate genes, and its suppression by siRNA resulted in the acceleration of growth inhibition in cell lines both transiently and endogenously expressing R175H but not in TP53-null cell lines or other common p53 mutants (such as R273H). Flow cytometry analysis showed that ID1 suppression resulted in G1 arrest, and the arrest was accelerated by the expression of R175H. ID1 is a synthetic sick/lethal gene that interacts with R175H and is considered to be a novel molecular target for cancer therapy in R175H-expressing cells.

IMAI, HIROO; KATO, SHUNSUKE; SAKAMOTO, YASUHIRO; KAKUDO, YUICHI; SHIMODAIRA, HIDEKI; ISHIOKA, CHIKASHI

2014-01-01

295

Synthesis, structure, and properties of REE mixed-ligand complexes containing dipivaloylmethanate and pivalate ligands: Mixed-ligand complexes of holmium, erbium, and ytterbium  

SciTech Connect

Solid mixed-ligand complexes (MLC) formed by the action of pivalic acid on holmium, erbium, and ytterbium dipivaloylmethanates (MDpm{sub 3}) in hexane are isolated. It is established from the data of the elemental and spectroscopic analyses that erbium and ytterbium MLC are of composition MDpm{sub 3}{center_dot}HPiv, and, in the case of holmium, a mixture of the complexes of composition HoDpm{sub 3}{center_dot}HPiv and HoDpm{sub 2}{center_dot}HPiv forms. The isostructural single crystals of HoDpm{sub 3}{center_dot}HPiv and ErDpm{sub 3}{center_dot}HPiv are prepared, and the unit cell parameters are determined. An X-ray diffraction study is carried out for HoDpm{sub 3}{center_dot}HPiv, and the crystal structure of this compounds is determined.

Kuz`mina, N.P.; An` Tu, Z.; Martynenko, L.I. [Moscow State Univ. (Russian Federation)] [and others

1994-09-01

296

Blue-green single-frequency laser based on intracavity frequency doubling of a diode-pumped Ytterbium-doped laser  

Microsoft Academic Search

Single-frequency lasers in the blue-green (500 nm) visible spectrum are important for many applications including iodine precision spectroscopy, optical frequency standards or ionized argon lasers substitution. To the best of our knowledge, we report in this paper the first single-frequency diode-pumped Ytterbium-doped solid-state laser operating at 501.7 nm by intracavity second harmonic generation (SHG). The single-frequency fundamental infrared laser light

Mathieu Jacquemet; Frédéric Druon; François Balembois; Patrick Georges; Bernard Ferrand

2005-01-01

297

Stable multigigahertz pulse-train formation in a short-cavity passively harmonic mode-locked erbium\\/ytterbium fiber laser  

Microsoft Academic Search

We demonstrate a short-cavity erbium -ytterbium fiber laser that is passively mode locked by a saturable Bragg ref lector with a fundamental repetition rate of 235 MHz. The laser operates in the soliton regime and under passive harmonic mode locking with 11 pulses in the cavity and produces output pulse trains at 2.6 GHz with transform-limited 270-fs pulses and 1.6

B. C. Collings; K. Bergman; W. H. Knox

1998-01-01

298

LT175 Is a Novel PPAR?/? Ligand with Potent Insulin-sensitizing Effects and Reduced Adipogenic Properties.  

PubMed

Peroxisome proliferator-activated receptors (PPARs) are ligand-dependent transcription factors regulating lipid and glucose metabolism. Ongoing drug discovery programs aim to develop dual PPAR?/? agonists devoid of the side effects of the marketed antidiabetic agents thiazolidinediones and the dual agonists glitazars. Recently, we described a new dual PPAR?/? ligand, LT175, with a partial agonist profile against PPAR? and interacting with a newly identified region of the PPAR?-ligand binding domain (1). Here we show that LT175 differentially activated PPAR? target genes involved in fatty acid esterification and storage in 3T3-L1-derived adipocytes. This resulted in a less severe lipid accumulation compared with that triggered by rosiglitazone, suggesting that LT175 may have a lower adipogenic activity. Consistent with this hypothesis, in vivo administration of LT175 to mice fed a high-fat diet decreased body weight, adipocyte size, and white adipose tissue mass, as assessed by magnetic resonance imaging. Furthermore, LT175 significantly reduced plasma glucose, insulin, non-esterified fatty acids, triglycerides, and cholesterol and increased circulating adiponectin and fibroblast growth factor 21 levels. Oral glucose and insulin tolerance tests showed that the compound improves glucose homeostasis and insulin sensitivity. Moreover, we demonstrate that the peculiar interaction of LT175 with PPAR? affected the recruitment of the coregulators cyclic-AMP response element-binding protein-binding protein and nuclear corepressor 1 (NCoR1), fundamentals for the PPAR?-mediated adipogenic program. In conclusion, our results describe a new PPAR ligand, modulating lipid and glucose metabolism with reduced adipogenic activity, that may be used as a model for a series of novel molecules with an improved pharmacological profile for the treatment of dyslipidemia and type 2 diabetes. PMID:24451380

Gilardi, Federica; Giudici, Marco; Mitro, Nico; Maschi, Omar; Guerrini, Uliano; Rando, Gianpaolo; Maggi, Adriana; Cermenati, Gaia; Laghezza, Antonio; Loiodice, Fulvio; Pochetti, Giorgio; Lavecchia, Antonio; Caruso, Donatella; De Fabiani, Emma; Bamberg, Krister; Crestani, Maurizio

2014-03-01

299

Coordinate phosphorylation of insulin-receptor kinase and its 175,000-Mr endogenous substrate in rat hepatocytes  

SciTech Connect

To investigate the early events in insulin signal transmission in liver, isolated rat hepatocytes were labeled with {sup 32}P, and proteins phosphorylated in response to insulin were detected by immunoprecipitation with anti-phosphotyrosine and anti-receptor antibodies and analyzed by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and autoradiography. In these cells, insulin rapidly stimulated tyrosine phosphorylation of the 95,000-Mr beta-subunit of the insulin receptor and a 175,000-Mr phosphoprotein (pp175). Both proteins were precipitated by anti-phosphotyrosine antibody, whereas only the insulin receptor was recognized with anti-insulin-receptor antibody. In the insulin-stimulated state, both pp175 and the receptor beta-subunit were found to be phosphorylated on tyrosine and serine residues. Based on precipitation by the two antibodies, receptor phosphorylation was biphasic with an initial increase in tyrosine phosphorylation followed by a more gradual increase in serine phosphorylation over the first 30 min of stimulation. The time course of phosphorylation of pp175 was rapid and paralleled that of the beta-subunit of the insulin receptor. The pp175 was clearly distinguished from the insulin receptor, because it was detected only when boiling SDS was used to extract cellular phosphoproteins, whereas the insulin receptor was extracted with either Triton X-100 or SDS. In addition, the tryptic peptide maps of the two proteins were distinct. The dose-response curve for insulin stimulation was shifted slightly to the left of the insulin receptor, suggesting some signal amplification at this step. These data suggest that pp175 is a major endogenous substrate of the insulin receptor in liver and may be a cytoskeletal-associated protein.

Okamoto, M.; Karasik, A.; White, M.F.; Kahn, C.R. (Joslin Diabetes Center, Boston, MA (USA))

1991-01-01

300

An 8-bit FLUX-1 RSFQ microprocessor built in 1.75-/?m technology  

NASA Astrophysics Data System (ADS)

This paper presents the first single-chip superconductor FLUX-1 microprocessor designed in the rapid single flux quantum logic and fabricated using 4 kA/cm 2, 1.75-?m Nb/AlO x/Nb Josephson junction (JJ) technology as a result of the collaboration between SUNY Stony Brook and TRW, Inc. A FLUX-1 chip represents an 8-bit microprocessor with a parallel architecture and a target clock frequency of 17-20 GHz. It includes the pipelined instruction memory, 8 integer arithmetic-logic units interleaved with eight registers, the branch unit, and I/O ports for 5-GHz chip-to-chip communication over Nb microstrip lines on a multi-chip module carrier. The FLUX-1 instruction set consists of ?25 arithmetic, logical, and control instructions. A FLUX-1 microprocessor chip contains 65,759 JJs on a 10.6×13.2 mm2 die with flip-chip packaging. First FLUX-1 chips fabricated in August 2001 are currently under testing at TRW, Inc.

Dorojevets, M.

2002-10-01

301

Corrosion-Fatigue Behavior of Aluminum Alloy 5083-H131 Sensitized at 448 K (175 °C)  

NASA Astrophysics Data System (ADS)

The fatigue crack growth behavior of aluminum alloy 5083-H131 has been systematically studied as a function of degree of sensitization for aging at 448 K (175 °C). Fatigue crack growth rates were measured at load ratios of 0.1 and 0.85, in vacuum, air, and a corrosive aqueous environment containing 1 pct NaCl with dilute inhibitor. Sensitization does not affect the fatigue crack growth behavior of Al 5083-H131 significantly in vacuum or air, at low- or high-load ratio. For high-load ratio, in the 1 pct NaCl+inhibitor solution, the threshold drops by nearly 50 pct during the first 200 hours of aging, then it degrades more slowly for longer aging times up to 2000 hours. The change in aging behavior at approximately 200 hours seems to be correlated with the transition from partial coverage of the grain boundaries by ? Al3Mg2 phase, to continuous full ? coverage. ASTM G-67 mass loss levels below approximately 30 mg/cm2 do not exhibit degraded corrosion-fatigue properties for R = 0.85, but degradation of the threshold is rapid for higher mass loss levels.

Holtz, Ronald L.; Pao, Peter S.; Bayles, Robert A.; Longazel, Thomas M.; Goswami, Ramasis

2012-08-01

302

Crystal structure of the flavohemoglobin from Alcaligenes eutrophus at 1.75 A resolution.  

PubMed Central

The molecular structure of the flavohemoglobin from Alcaligenes eutrophus has been determined to a resolution of 1.75 A and refined to an R-factor of 19.6%. The protein comprises two fused modules: a heme binding module, which belongs to the globin family, and an FAD binding oxidoreductase module, which adopts a fold like ferredoxin reductase. The most striking deviation of the bacterial globin structure from those of other species is the movement of helix E in a way to provide more space in the vicinity of the distal heme binding site. A comparison with other members of the ferredoxin reductase family shows similar tertiary structures for the individual FAD and NAD binding domains but largely different interdomain orientations. The heme and FAD molecules approach each other to a minimal distance of 6.3 A and adopt an interplanar angle of 80 degrees. The electron transfer from FAD to heme occurs in a predominantly polar environment and may occur directly or be mediated by a water molecule. Images

Ermler, U; Siddiqui, R A; Cramm, R; Friedrich, B

1995-01-01

303

Intermetallic growth of wire-bond at 175°C high temperature aging  

NASA Astrophysics Data System (ADS)

Two types of samples were applied in this wire-bond evaluation work for an Al-pad diffusion process. One was finished product for the cross-section examination of wire-bond and the other was without compound encapsulant used for the plane view examination of wire-bond interface. These samples were aged at 175 C in air from 0 h to 1008 h. It is found that the normal product which was ready on board existed ˜1 ?m Au2Al and Au5Al2 phases. The Au2Al phase was then transformed to Au5Al2 phase in a 4 ˜ 72 h aging period. The Au4Al phase formed along with the Au5Al2 phase in 72 h to 240 h aging period showing some porosity within the reacted phases. The total phase thickness increased to ˜4?m after 240 h aging. The Au4Al phase became the major phase after 336 aging h. The reacted phase layer thickness increased to ˜6 ?m and reached the steady state. A titanium-rich thin layer was also induced within the reacted phase layer. Three ternary phases as AlAu2Ti, AlAuTi, and Al2Au2Ti are found in this titanium-rich layer. In particular, Al2Au2Ti could be a new phase.

Chang, Hen-So; Pon, J. X.; Hsieh, Ker-Chang; Chen, C. C.

2001-09-01

304

175 GHz, 400-fs-pulse harmonically mode-locked surface emitting semiconductor laser.  

PubMed

We report a harmonically mode-locked vertical external cavity surface emitting laser (VECSEL) producing 400 fs pulses at a repetition frequency of 175 GHz with an average output power of 300 mW. Harmonic mode-locking was established using a 300 µm thick intracavity single crystal diamond heat spreader in thermal contact with the front surface of the gain sample using liquid capillary bonding. The repetition frequency was set by the diamond microcavity and stable harmonic mode locking was achieved when the laser cavity length was tuned so that the laser operated on the 117th harmonic of the fundamental cavity. When an etalon placed intracavity next to the gain sample, but not in thermal contact was used pulse groups were observed. These contained 300 fs pulses with a spacing of 5.9 ps. We conclude that to achieve stable harmonic mode locking at repetition frequencies in the 100s of GHz range in a VECSEL there is a threshold pulse energy above which harmonic mode locking is achieved and below which groups of pulses are observed. PMID:22453384

Wilcox, Keith G; Quarterman, Adrian H; Apostolopoulos, Vasilis; Beere, Harvey E; Farrer, Ian; Ritchie, David A; Tropper, Anne C

2012-03-26

305

Antagomir-17-5p Abolishes the Growth of Therapy-Resistant Neuroblastoma through p21 and BIM  

PubMed Central

We identified a key oncogenic pathway underlying neuroblastoma progression: specifically, MYCN, expressed at elevated level, transactivates the miRNA 17-5p-92 cluster, which inhibits p21 and BIM translation by interaction with their mRNA 3? UTRs. Overexpression of miRNA 17-5p-92 cluster in MYCN-not-amplified neuroblastoma cells strongly augments their in vitro and in vivo tumorigenesis. In vitro or in vivo treatment with antagomir-17-5p abolishes the growth of MYCN-amplified and therapy-resistant neuroblastoma through p21 and BIM upmodulation, leading to cell cycling blockade and activation of apoptosis, respectively. In primary neuroblastoma, the majority of cases show a rise of miR-17-5p level leading to p21 downmodulation, which is particularly severe in patients with MYCN amplification and poor prognosis. Altogether, our studies demonstrate for the first time that antagomir treatment can abolish tumor growth in vivo, specifically in therapy-resistant neuroblastoma.

Fontana, Laura; Cifaldi, Loredana; Giovinazzi, Serena; Forloni, Matteo; Boldrini, Renata; Donfrancesco, Alberto; Federici, Valentina; Giacomini, Patrizio; Peschle, Cesare; Fruci, Doriana

2008-01-01

306

A Beamforming Study for Implementation of Vibro-acoustography with a 1.75D Array Transducer  

PubMed Central

Vibro-acoustography (VA) is an ultrasound-based imaging modality that uses radiation force produced by two cofocused ultrasound beams separated by a small frequency difference, ?f, to vibrate tissue at ?f. An acoustic field is created by the object vibration and measured with a nearby hydrophone. This method has recently been implemented on a clinical ultrasound system using one-dimensional (1D) linear array transducers. In this article, we discuss VA beamforming and image formation using a 1.75D array transducer. A 1.75D array transducer has several rows of elements in the elevation direction which can be controlled independently for focusing. The advantage of the 1.75D array over a 1D linear array transducer is that multiple rows of elements can be used for improving elevation focus for imaging formation. Six configurations for subaperture design for the two ultrasound beams necessary for VA imaging were analyzed. The point-spread functions for these different configurations were evaluated using a numerical simulation model. Four of these configurations were then chosen for experimental evaluation with a needle hydrophone as well as for scanning two phantoms. Images were formed by scanning a urethane breast phantom and an ex vivo human prostate. VA imaging using a 1.75D array transducer offers several advantages over scanning with a linear array transducer including improved image resolution and contrast due to better elevation focusing of the imaging point-spread function.

Urban, Matthew W.; Chalek, Carl; Haider, Bruno; Thomenius, Kai E.; Fatemi, Mostafa; Alizad, Azra

2013-01-01

307

A beamforming study for implementation of vibro-acoustography with a 1.75-D array transducer.  

PubMed

Vibro-acoustography (VA) is an ultrasound-based imaging modality that uses radiation force produced by two cofocused ultrasound beams separated by a small frequency difference, ?f, to vibrate tissue at ?f. An acoustic field is created by the object vibration and measured with a nearby hydrophone. This method has recently been implemented on a clinical ultrasound system using 1-D linear-array transducers. In this article, we discuss VA beamforming and image formation using a 1.75-D array transducer. A 1.75-D array transducer has several rows of elements in the elevation direction which can be controlled independently for focusing. The advantage of the 1.75-D array over a 1-D linear-array transducer is that multiple rows of elements can be used for improving elevation focus for imaging formation. Six configurations for subaperture design for the two ultrasound beams necessary for VA imaging were analyzed. The point-spread functions for these different configurations were evaluated using a numerical simulation model. Four of these configurations were then chosen for experimental evaluation with a needle hydrophone as well as for scanning two phantoms. Images were formed by scanning a urethane breast phantom and an ex vivo human prostate. VA imaging using a 1.75-D array transducer offers several advantages over scanning with a linear-array transducer, including improved image resolution and contrast resulting from better elevation focusing of the imaging point-spread function. PMID:23475919

Urban, Matthew W; Chalek, Carl; Haider, Bruno; Thomenius, Kai E; Fatemi, Mostafa; Alizad, Azra

2013-03-01

308

Paleoclimatic changes in southern Africa during the intensification of Northern Hemisphere glaciation: evidence from ODP Leg 175 Site 1085  

Microsoft Academic Search

Pliocene age sediments from Ocean Drilling Program Leg 175, Site 1085-A and B in the Cape Basin were analyzed to investigate the impact of the intensification of Northern Hemisphere glaciation (INHG) on the South Atlantic Benguela Current system from 4 to 2 Ma. Proxies for productivity (concentrations and mass accumulation rates of total organic carbon, carbon to nitrogen ratios, percent

B. A. Christensen; J. L. Kalbas; M. Maslin; R. W. Murray

2002-01-01

309

The flexibility of two tropomyosin mutants, D175N and E180G, that cause hypertrophic cardiomyopathy  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Well-known tropomyosin mutants, D175N and E180G are linked to cardiomyopathies. Black-Right-Pointing-Pointer The structural mechanics of D175N and E180G tropomyosins have been investigated. Black-Right-Pointing-Pointer D175N and E180G mutations increase both local and global tropomyosin flexibility. Black-Right-Pointing-Pointer In muscle, this increased flexibility will enhance myosin interactions on actin. Black-Right-Pointing-Pointer Extra myosin interaction can alter cardiac Ca{sup 2+}-switching, leading to dysfunction. -- Abstract: Point mutations targeting muscle thin filament proteins are the cause of a number of cardiomyopathies. In many cases, biological effects of the mutations are well-documented, whereas their structural and mechanical impact on filament assembly and regulatory function is lacking. In order to elucidate molecular defects leading to cardiac dysfunction, we have examined the structural mechanics of two tropomyosin mutants, E180G and D175N, which are associated with hypertrophic cardiomyopathy (HCM). Tropomyosin is an {alpha}-helical coiled-coil dimer which polymerizes end-to-end to create an elongated superhelix that wraps around F-actin filaments of muscle and non-muscle cells, thus modulating the binding of other actin-binding proteins. Here, we study how flexibility changes in the E180G and D175N mutants might affect tropomyosin binding and regulatory motion on F-actin. Electron microscopy and Molecular Dynamics simulations show that E180G and D175N mutations cause an increase in bending flexibility of tropomyosin both locally and globally. This excess flexibility is likely to increase accessibility of the myosin-binding sites on F-actin, thus destabilizing the low-Ca{sup 2+} relaxed-state of cardiac muscle. The resulting imbalance in the on-off switching mechanism of the mutants will shift the regulatory equilibrium towards Ca{sup 2+}-activation of cardiac muscle, as is observed in affected muscle, accompanied by enhanced systolic activity, diastolic dysfunction, and cardiac compensations associated with HCM and heart failure.

Li, Xiaochuan; Suphamungmee, Worawit [Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118 (United States)] [Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118 (United States); Janco, Miro; Geeves, Michael A. [School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ (United Kingdom)] [School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ (United Kingdom); Marston, Steven B. [National Heart and Lung Institute, Imperial College London, London W12 0NN (United Kingdom)] [National Heart and Lung Institute, Imperial College London, London W12 0NN (United Kingdom); Fischer, Stefan, E-mail: stefan.fischer@iwr.uni-heidelberg.de [Computational Biochemistry Group, University of Heidelberg, Heidelberg D-69120 (Germany)] [Computational Biochemistry Group, University of Heidelberg, Heidelberg D-69120 (Germany); Lehman, William, E-mail: wlehman@bu.edu [Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118 (United States)] [Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118 (United States)

2012-08-03

310

LDEF (Postflight), AO175 : Evaluation of Long-Duration Exposure to the Natural Space Environment on  

NASA Technical Reports Server (NTRS)

LDEF (Postflight), AO175 : Evaluation of Long-Duration Exposure to the Natural Space Environment on Graphite-Polyimide and Graphite-Epoxy Mechanical Properties, Tray A07 The postflight photograph was taken in the Operations and Control (O&C) facility after the LDEF had been transferred from the KSC Payload Transporter to the LDEF Assembly and Transport System (LATS) and shows more detail than the flight photograph. The areas on the aluminum mounting strips where the coating has been scraped and/or abraided can be seen in greater detail under the better lighting conditions. The coating color remains essentially the same. The white paint dots on the tray clampblocks have changed little from the orginal color. PMR-15 Graphite-Polyimide Panel (precured) - The PMR-15 graphite-polyimide laminated panel (T40T30060-009) postflight photograph provides more detail than the flight photograph. The geometric pattern seen on the flight photograph is not visible, however, the horizontal lines, cracks and/or crazing, observed previously are better defined. A gray haze or dust appears to cover the gray/brown panel surface. The yellow colored identification numbers seem to be a little lighter than in the flight photograph but the white marking in the upper left corner do not appear to have changed. Scratch marks/abrasions on the lower left edge of panel were on prelaunch photographs. F-178/T300 Graphite-Polyimide Panel (cocured) - The 178/T300 graphite-polyimide panel (T40T30060-005) seems to have changed in color from the light gray in the flight photograph to a brownish gray. The yellow identification numbers seem lighter while the white marking in the upper left corner appear brighter. The fine horizontal lines, cracks and/or crazing, are still visible on the panel surface. F178/T300 Graphite-Polyimide Panel (precured) - The 178/T300 graphite-polyimide laminated panel (T40T30060-001) seems to have changed to a brownish gray from the light gray color seen in the flight photograph. The yellow identification numbers and the white marking seen on the lower right corner of the panel appear the same as in the flight photograph. The fine horizontal lines, cracks and/or crazing, are still visible on the panel surface.

1990-01-01

311

Observation of an octupole{circle_times}quasiparticle band in {sup 175}Lu using photon scattering experiments  

SciTech Connect

A nuclear resonance fluorescence (NRF) study was performed on the heavy deformed nucleus {sup 175}Lu. We observe the beginning of a rotational band built on the coupling of the unpaired proton to the K{sup {pi}}=0{sup {minus}} octupole vibration in the neighboring nucleus {sup 174}Yb. The dipole strength distribution is also discussed in terms of the scissors mode. {copyright} {ital 1997} {ital The American Physical Society}

Herzberg, R.-D.; Fransen, C.; Fischer, R.; von Brentano, P.; Pietralla, N. [Institut fuer Kernphysik, Universitaet zu Koeln, D-50937 Koeln (Germany)] [Institut fuer Kernphysik, Universitaet zu Koeln, D-50937 Koeln (Germany); Belic, D.; Besserer, J.; Eckert, Th.; Kneissl, U.; Krischok, B.; Margraf, J.; Maser, H.; Nord, A.; Pitz, H.H.; Wolpert, A. [Institut fuer Strahlenphysik, Universitaet Stuttgart, D-70569 Stuttgart (Germany)] Zilges, A. [Institut fuer Kernphysik, Technische Hochschule Darmstadt, D-64289 Darmstadt (Germany)

1997-11-01

312

Is the dialysate calcium concentration of 1.75 mmol/L suitable for chinese patients on maintenance hemodialysis?  

PubMed

We studied the effects of increasing the dialysate calcium concentration (DCa) to 1.75 mmol/L on controlling chronic kidney disease-mineral and bone disorder in Chinese patients on maintenance hemodialysis (MHD). We reviewed the data of MHD patients in one center (cohort 1) during prior 10 years and analyzed the risk factors of mortality and transference calcification (TC) in120 MHD patients surviving in 2003 (cohort 2). A multicenter, prospective, parallel-group, controlled trial (cohort 3) was also conducted from January 2011 to December 2012. The DCa at one center was increased from 1.5 to 1.75 mmol/L but was not changed at the other two centers. The clinical outcomes, biochemical parameters, medicine treatments, and TC markers [aortic arch calcification score (AoACS)] were compared between groups. In cohort 1, the annual mean serum iPTH increased significantly over 10 years. In cohort 1, 72 patients survived for 10 years, whose doses of calcium salts and active vitamin D3 and AoACs increased progressively. In cohort 2, the main cause of death was cardiocerebrovascular disease (CCVD) (n = 18, 48.6 %). Male sex and lower serum calcium concentrations were independent risk factors for CCVD mortality. In cohort 3, serum phosphorus, iPTH, and 25(OH)D decreased and serum calcium increased significantly; also, the doses of calcium and vitamin D3 decreased from 2011 to 2012 in the DCa 1.75 group. There were no significant differences in clinical outcomes either between groups or between the two calendar years. Our results indicate that increasing DCa to 1.75 mmol/L can decrease the elevated levels of serum iPTH and phosphorus, reduce the doses of calcium and vitamin D3, and be safe for short periods of time. PMID:24193439

Zhang, Dong-liang; Wang, Li-yan; Sun, Fang; Zhou, Yi-lun; Duan, Xiao-feng; Liu, Sha; Sun, Yi; Cui, Tai-gen; Liu, Wen-hu

2014-03-01

313

Intermetallic growth in gold ball bonds aged at 175°C: comparison between two 4N wires of different chemistry  

Microsoft Academic Search

Gold wires of different chemistry (denoted as Types A and B) are ballbonded on identical metallization and isothermally aged\\u000a at 175°C. In both wire types the same intermetallic compounds Au4Al and Au8Al3 grow with parabolic time dependence as long as there is a supply of Al from the bondpad. After Al is completely reacted,\\u000a composition of intermetallics in Type A

C. D. Breach; F. W. Wulff

2009-01-01

314

Widely tunable all-fiber optical parametric oscillator based on a photonic crystal fiber pumped by a picosecond ytterbium-doped fiber laser.  

PubMed

We report on a fully fiber-integrated widely tunable optical parametric oscillator based on a photonic crystal fiber pumped by a picosecond ytterbium-doped fiber laser. The output wavelength of the oscillator can be continuously tuned from 898 to 1047 nm and from 1086 to 1277 nm, which is as wide as 340 nm. In particular, a larger Raman gain peak is simultaneously observed when the pump wavelength is far from the zero-dispersion wavelength in the normal-dispersion regime. The bandwidth of the output of the oscillator can be tuned by slightly adjusting the pump power. PMID:24322067

Zhang, Lei; Yang, Sigang; Wang, Xiaojian; Gou, Doudou; Li, Xiangliang; Chen, Hongwei; Chen, Minghua; Xie, Shizhong

2013-11-15

315

Design and evaluation of a 63 element 1.75-dimensional ultrasound phased array for treating benign prostatic hyperplasia  

NASA Astrophysics Data System (ADS)

Focused ultrasound surgery (FUS) is a clinical method for treating benign prostatic hyperplasia (BPH) in which tissue is noninvasively necrosed by elevating the temperature at the focal point above 60°C using short sonications. With 1.75-dimensional (1.75-D) arrays, the power and phase to the individual elements can be controlled electronically for focusing and steering. This research describes the design, construction and evaluation of a 1.75-D ultrasound phased array to be used in the treatment of benign prostatic hyperplasia. The array was designed with a steering angle of +/-13.5 deg in the transverse direction, and can move the focus in three parallel planes in the longitudinal direction with a relatively large focus size. A piezoelectric ceramic (PZT-8) was used as the material of the transducer and two matching layers were built for maximum acoustic power transmission to tissue. To verify the capability of the transducer for focusing and steering, exposimetry was performed and the results correlated well with the calculated fields. In vivo experiments were performed to verify the capability of the transducer to ablate tissue using short sonications. [Work supported by the Whitaker Foundation and the Department of Defense Congressionally Directed Medical Prostate Cancer Research Program.

Saleh, Khaldon Y.; Smith, Nadine B.

2003-10-01

316

Growth, spectroscopic properties and laser performance of Nd{sup 3+}-doped potassium ytterbium tungstate laser crystal  

SciTech Connect

The 5 at.% Nd{sup 3+}-doped potassium ytterbium tungstate (Nd{sup 3+}:KYb(WO{sub 4}){sub 2}, hereafter Nd:KYbW) laser crystal with the dimension up to 28 mm x 15 mm x 12 mm was grown by the top seeded solution growth (TSSG) method. The infrared spectrum of crystal sample was measured, and the vibrational peaks were assigned. According to the absorption and emission spectra of crystal sample, the absorption and emission cross-sections are 16.03 x 10{sup -20} cm{sup 2} at 808 nm and 10.72 x 10{sup -20} cm{sup 2} at 1067 nm, respectively. The fluorescence life of {sup 4}F{sub 3/2} energy level is 196.33 {mu}s, and the fluorescence branching ratio for the {sup 4}F{sub 3/2}-{sup 4}I{sub 11/2} transition at 1067 nm is 55.74%. The energy transfer between Nd{sup 3+} and Yb{sup 3+} ions was observed from the fluorescence spectra pumped by 808 and 980 nm LD sources and the Stark levels of Yb{sup 3+} in Nd:KYbW crystal were determined. Highly efficient laser output up to 305 mW of Nd:KYbW crystal at 1067 nm has been achieved under pumping by a CW 808 nm laser diode at room temperature. The optical-optical conversion efficiency is 33.9% and the slope efficiency is 46.8%.

Zhang, Ying, E-mail: starsugar_zy@163.com [College of Materials Science and Engineering, Changchun University of Science and Technology, No. 7989 WeiXing Road, Jilin Province, Changchun 130022 (China)] [College of Materials Science and Engineering, Changchun University of Science and Technology, No. 7989 WeiXing Road, Jilin Province, Changchun 130022 (China); Zeng, Fanming; Lin, Hai; Li, Chun; Qin, Jieming; Zhang, Xuejian; Wang, Chengwei; Liu, Jinghe [College of Materials Science and Engineering, Changchun University of Science and Technology, No. 7989 WeiXing Road, Jilin Province, Changchun 130022 (China)] [College of Materials Science and Engineering, Changchun University of Science and Technology, No. 7989 WeiXing Road, Jilin Province, Changchun 130022 (China)

2010-08-15

317

Recent advances in ytterbium-based contrast agents for in vivo X-ray computed tomography imaging: promises and prospects.  

PubMed

X-ray computed tomography (CT) imaging is one of the most widely used diagnostic imaging techniques in the clinic, and has raised significant interest in recent years both in research and practice owing to its many advantages such as deep penetration depth, high resolution and facile image processing. Developing heavy metal-based CT contrast agents, especially heavy metal-containing nanoparticulate CT contrast agents, has become a key focus in research fields to address issues of clinical iodinated agents involving short circulation time, low contrast efficiency and potential renal toxicity. In this review, we summarize the development of ytterbium (Yb)-based CT contrast agents and highlight the design and applications of Yb-based nanoparticulate CT contrast agents. Yb has high atomic number and higher abundance in the earth's crust relative to Au, Ta and Bi, which have received much attention as a CT contrast agents. In particular, in contrast to these metal elements, as well as I, Yb has K-edge energy that is located just within the higher-intensity region of X-ray spectra, which can induce significant enhancement in the contrast efficiency. When encapsulated in nanoparticles, Yb can remain in the circulation for a long time. This long in vivo circulation time, combined with the proper K-edge energy and a large absorption cross-section of Yb in the near-infrared region, makes Yb-based nanoparticles particularly promising in angiography, 'multicolor' spectral CT imaging, and multimodal imaging. Finally, we also discuss the prospects and the challenges in the development of Yb-based CT contrast agents. PMID:24470292

Liu, Yanlan; Liu, Jianhua; Ai, Kelong; Yuan, Qinghai; Lu, Lehui

2014-01-01

318

Investigation of superfast deposition of metal oxide and Diamond-Like Carbon thin films by nanosecond Ytterbium (Yb+) fiber laser  

NASA Astrophysics Data System (ADS)

Metal oxide (MOx, M: titanium, magnesium) and Diamond-Like Carbon (DLC) thin films were synthesized by Pulsed Laser Deposition (PLD) at room temperature and low vacuum of 2 Pa for MOx and vacuum of 4 × 10-3 Pa for DLC films. A fiber based Ytterbium (Yb+) laser operating in the nanosecond regime at a repetition rate of 20 kHz was used as an ablation source. Dense and smooth thin films with a thickness from 120 to 360 nm and an area of up to 10 cm2 were deposited on glass and stainless steel substrates at high growth rates up to 2 nm/s for a laser intensity of 10-12 J/cm2. The thin films synthesis was compared for two fiber laser modes of operation, at a repetition rate of 20 kHz and with an additional modulation at 1 kHz. The morphology, chemical composition and structure of the obtained thin films were evaluated using optical microscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX) and Raman spectroscopy. The morphology of the MOx thin films and the deposition rate strongly depend on the fiber laser mode of operation. Very smooth surfaces were obtained for the metal oxide thin films deposited at lower deposition rates in the modulation mode at 1 kHz. The effect of the substrate on the DLC film structure was studied. The films deposited on dielectric substrates were identified as typical tetrahedral (ta-C) DLC with high sp3 content. DLC films on metal substrates were found typical a-C amorphous carbon films with mixing sp2/sp3 bonds.

Serbezov, V.; Sotirov, S.; Benkhouja, K.; Zawadzka, A.; Sahraoui, B.

2013-11-01

319

Measurement of atomic oscillator strengths in ytterbium by observation of coherent Rabi oscillations of excited-state populations  

SciTech Connect

Two methods have been used to measure the oscillator strength of the transition between the ground and 17,992 cm level in XUYb. The first technique involves exciting the transition with a laser pulse that is nearly time-bandwidth limited, of uniform intensity, and has a reproducible shape from shot to shot. The population left in the excited state after the pulse varies sinusoidally with a period that depends on the integral over time of the electric field amplitude and the transition oscillator strength. These are the Rabi oscillations that are predicted by application of the Schrodinger equation to the two-level atom. The second method involves observation of the polarization rotation of a set of degenerate sublevels brought about by a light-shift laser. One sublevel (m/sub j/ = 0) of the J = 1 level at 17,992 cm is populated by a linearly polarized laser. A second copropagating light-shift laser, which is linearly polarized at an angle to the first laser, is tuned between 7.5 and 30 GHz off-resonance with the transition. The light-shift laser causes population to be promoted into the m/sub j/ = +-1 levels through the virtual J = 0, m/sub j/ = 0 level. Two linearly polarized photoionizing lasers photoionize the population only from the m/sub j/ = +-1 levels. The photoion signal oscillates cosinusoidally with a period that depends only on the integrated pulse intensity, the laser detuning, and the transition oscillator strength. Finally, polarization selectivity has been shown experimentally to allow selective photoionization of the odd isotopes of ytterbium using broadband lasers.

Haynam, C.A.; Comaskey, B.J.; Worden, E.F.; Paisner, J.A.

1987-01-01

320

Sistematika i analiz svojstv yader nechetnykh izotopov itterbiya s A = 163-173. Vrashchatel'nye sostoyaniya. (Systematics and analysis of properties of ytterbium odd nuclei with A = 163-173. Rotational states).  

National Technical Information Service (NTIS)

The energies and structure of rotational states in odd ytterbium nuclei with A = 163-173 mass number are calculated in the framework of nonadiabatic rotational model and a modified rotational model taking into account the recoil term and quasiparticle-pho...

I. Adam K. Badalov J. Wawryszcruk W. Wagner K. Gromov

1988-01-01

321

Mechanisms for auto-inhibition and forced product release in glycine N-methyltransferase: crystal structures of wild-type, mutant R175K and S-adenosylhomocysteine-bound R175K enzymes.  

PubMed

Glycine N-methyltransferase (S-adenosyl-l-methionine: glycine methyltransferase, EC 2.1.1.20; GNMT) catalyzes the AdoMet-dependent methylation of glycine to form sarcosine (N-methylglycine). Unlike most methyltransferases, GNMT is a tetrameric protein showing a positive cooperativity in AdoMet binding and weak inhibition by S-adenosylhomocysteine (AdoHcy). The first crystal structure of GNMT complexed with AdoMet showed a unique "closed" molecular basket structure, in which the N-terminal section penetrates and corks the entrance of the adjacent subunit. Thus, the apparent entrance or exit of the active site is not recognizable in the subunit structure, suggesting that the enzyme must possess a second, enzymatically active, "open" structural conformation. A new crystalline form of the R175K enzyme has been grown in the presence of an excess of AdoHcy, and its crystal structure has been determined at 3.0 A resolution. In this structure, the N-terminal domain (40 amino acid residues) of each subunit has moved out of the active site of the adjacent subunit, and the entrances of the active sites are now opened widely. An AdoHcy molecule has entered the site occupied in the "closed" structure by Glu15 and Gly16 of the N-terminal domain of the adjacent subunit. An AdoHcy binds to the consensus AdoMet binding site observed in the other methyltransferase. This AdoHcy binding site supports the glycine binding site (Arg175) deduced from a chemical modification study and site-directed mutagenesis (R175K). The crystal structures of WT and R175K enzymes were also determined at 2.5 A resolution. These enzyme structures have a closed molecular basket structure and are isomorphous to the previously determined AdoMet-GNMT structure. By comparing the open structure to the closed structure, mechanisms for auto-inhibition and for the forced release of the product AdoHcy have been revealed in the GNMT structure. The N-terminal section of the adjacent subunit occupies the AdoMet binding site and thus inhibits the methyltransfer reaction, whereas the same N-terminal section forces the departure of the potentially potent inhibitor AdoHcy from the active site and thus facilitates the methyltransfer reaction. Consequently GNMT is less active at a low level of AdoMet concentration, and is only weakly inhibited by AdoHcy. These properties of GNMT are particularly suited for regulation of the cellular AdoMet/AdoHcy ratio. PMID:10756111

Huang, Y; Komoto, J; Konishi, K; Takata, Y; Ogawa, H; Gomi, T; Fujioka, M; Takusagawa, F

2000-04-21

322

175 MeV Au+13 ion irradiation induced structural and morphological modifications in zinc oxide thin films  

NASA Astrophysics Data System (ADS)

Thin films of ZnO were deposited, on Si substrates, using the RF-sputtering technique and irradiated by the 175 MeV Au+13 beams. The structural changes were investigated by x-ray diffraction (XRD) measurements. The particle size found to increase with the increasing ion fluence up to 1×1012 ion/cm2. At highest irradiation fluence of 5×1012 ion/cm2 the average particle size decreases. The Raman spectroscopy measurements were performed to understand the local phonon mode of the samples. The surface morphology of the as-deposited and irradiated thin films is measured by the Atomic Force Microscopy (AFM).

Singh, Devendra; Sharma, Aditya; Varshney, Mayora; Kumar, Shalendra; Verma, K. D.

2013-02-01

323

41 CFR 102-38.175 - How do we find out if a person or entity has been suspended or debarred from doing business with...  

Code of Federal Regulations, 2013 CFR

...has been suspended or debarred from doing business with the Government? 102-38.175...has been suspended or debarred from doing business with the Government? Refer to...Internet at http://epls.arnet.gov. For policies, procedures,...

2013-07-01

324

Phosphorylation of CDK9 at Ser175 Enhances HIV Transcription and Is a Marker of Activated P-TEFb in CD4+ T Lymphocytes  

PubMed Central

The HIV transactivator protein, Tat, enhances HIV transcription by recruiting P-TEFb from the inactive 7SK snRNP complex and directing it to proviral elongation complexes. To test the hypothesis that T-cell receptor (TCR) signaling induces critical post-translational modifications leading to enhanced interactions between P-TEFb and Tat, we employed affinity purification–tandem mass spectrometry to analyze P-TEFb. TCR or phorbal ester (PMA) signaling strongly induced phosphorylation of the CDK9 kinase at Ser175. Molecular modeling studies based on the Tat/P-TEFb X-ray structure suggested that pSer175 strengthens the intermolecular interactions between CDK9 and Tat. Mutations in Ser175 confirm that this residue could mediate critical interactions with Tat and with the bromodomain protein BRD4. The S175A mutation reduced CDK9 interactions with Tat by an average of 1.7-fold, but also completely blocked CDK9 association with BRD4. The phosphomimetic S175D mutation modestly enhanced Tat association with CDK9 while causing a 2-fold disruption in BRD4 association with CDK9. Since BRD4 is unable to compete for binding to CDK9 carrying S175A, expression of CDK9 carrying the S175A mutation in latently infected cells resulted in a robust Tat-dependent reactivation of the provirus. Similarly, the stable knockdown of BRD4 led to a strong enhancement of proviral expression. Immunoprecipitation experiments show that CDK9 phosphorylated at Ser175 is excluded from the 7SK RNP complex. Immunofluorescence and flow cytometry studies carried out using a phospho-Ser175-specific antibody demonstrated that Ser175 phosphorylation occurs during TCR activation of primary resting memory CD4+ T cells together with upregulation of the Cyclin T1 regulatory subunit of P-TEFb, and Thr186 phosphorylation of CDK9. We conclude that the phosphorylation of CDK9 at Ser175 plays a critical role in altering the competitive binding of Tat and BRD4 to P-TEFb and provides an informative molecular marker for the identification of the transcriptionally active form of P-TEFb.

Mbonye, Uri R.; Gokulrangan, Giridharan; Datt, Manish; Dobrowolski, Curtis; Cooper, Maxwell; Chance, Mark R.; Karn, Jonathan

2013-01-01

325

Evaluation of colocalization interactions between the IE110, IE175, and IE63 transactivator proteins of herpes simplex virus within subcellular punctate structures.  

PubMed Central

A number of previous studies have implied that three herpes simplex virus-encoded nuclear transactivator proteins, IE175 (ICP4), IE110 (ICP0), and IE63 (ICP27), may cooperate in transcriptional and posttranscriptional stimulation of viral gene expression. Using double-label immunofluorescence assays (IFA) in transient expression assays, we have examined the intracellular localization of these three proteins in DNA-transfected cells. The IE110 protein on its own forms spherical punctate domains within the nucleus, whereas the IE175 and IE63 proteins alone give uniform and speckled diffuse patterns, respectively. In infected cells, the IE110 punctate granules have been shown to correspond to novel preexisting subnuclear structures referred to as ND10 domains or PODs that contain a variety of cellular proteins, including SP100 and the PML proto-oncogene product. Cotransfection experiments with wild-type nuclear forms of both IE175 and IE110 provided direct evidence for partial redistribution of IE175 into the same punctate granules that contained IE110. Surprisingly, nuclear forms of IE110 were found to move a cytoplasmic form of IE175 into nuclear punctate structures, and a cytoplasmic form of IE110 was able to retain nuclear forms of IE175 in cytoplasmic punctate structures. Therefore, the punctate characteristic of IE110 appeared to both dominate the interactions and override the normal nuclear localization signals. The domains responsible for the interaction mapped to between codons 518 and 768 in 1E110 and to between codons 835 and 1029 in IE175. Importantly, a truncated nuclear form of the 1,298-amino-acid IE175 protein, which lacked the C-terminal domain beyond codon 834, was found to be excluded from the IE110 punctate granules. Cotransfection of nuclear or cytoplasmic IE110 with a truncated nuclear form of IE63 also led to partial redistribution of IE63 into either nuclear or cytoplasmic punctate granules containing IE110. Both the IE63-IE110 and IE175-IE110 colocalization interactions were demonstrated in Vero cells but not in 293 cells. Consequently, they differ from IE110 self-interactions, which correlate with in vitro dimerization and occur efficiently in both cell types. These interactions may help to explain the altered promoter target specificity and synergism observed when IE175 is cotransfected with IE110 in transactivation studies.

Mullen, M A; Gerstberger, S; Ciufo, D M; Mosca, J D; Hayward, G S

1995-01-01

326

Comprehensive Behavioral and Molecular Characterization of a New Knock-In Mouse Model of Huntington's Disease: zQ175  

PubMed Central

Huntington’s disease (HD) is an autosomal dominant neurodegenerative disorder characterized by motor, cognitive and psychiatric manifestations. Since the mutation responsible for the disease was identified as an unstable expansion of CAG repeats in the gene encoding the huntingtin protein in 1993, numerous mouse models of HD have been generated to study disease pathogenesis and evaluate potential therapeutic approaches. Of these, knock-in models best mimic the human condition from a genetic perspective since they express the mutation in the appropriate genetic and protein context. Behaviorally, however, while some abnormal phenotypes have been detected in knock-in mouse models, a model with an earlier and more robust phenotype than the existing models is required. We describe here for the first time a new mouse line, the zQ175 knock-in mouse, derived from a spontaneous expansion of the CAG copy number in our CAG 140 knock-in colony [1]. Given the inverse relationship typically observed between age of HD onset and length of CAG repeat, since this new mouse line carries a significantly higher CAG repeat length it was expected to be more significantly impaired than the parent line. Using a battery of behavioral tests we evaluated both heterozygous and homozygous zQ175 mice. Homozygous mice showed motor and grip strength abnormalities with an early onset (8 and 4 weeks of age, respectively), which were followed by deficits in rotarod and climbing activity at 30 weeks of age and by cognitive deficits at around 1 year of age. Of particular interest for translational work, we also found clear behavioral deficits in heterozygous mice from around 4.5 months of age, especially in the dark phase of the diurnal cycle. Decreased body weight was observed in both heterozygotes and homozygotes, along with significantly reduced survival in the homozygotes. In addition, we detected an early and significant decrease of striatal gene markers from 12 weeks of age. These data suggest that the zQ175 knock-in line could be a suitable model for the evaluation of therapeutic approaches and early events in the pathogenesis of HD.

Menalled, Liliana B.; Kudwa, Andrea E.; Miller, Sam; Fitzpatrick, Jon; Watson-Johnson, Judy; Keating, Nicole; Ruiz, Melinda; Mushlin, Richard; Alosio, William; McConnell, Kristi; Connor, David; Murphy, Carol; Oakeshott, Steve; Kwan, Mei; Beltran, Jose; Ghavami, Afshin; Brunner, Dani; Park, Larry C.; Ramboz, Sylvie; Howland, David

2012-01-01

327

Diffuse X-ray scattering and reverse Monte Carlo simulation of the short-range order in ytterbium iodine phthalocyanine [YbPc(2)]I(2).  

PubMed

Iodine-doped ytterbium phthalocyanine, C(64)H(32)N(16)YbI(2), [YbPc(2)]I(2) (YPI), presents an example of a disordered modulated crystal structure of the intergrowth type. The short-range order in YPI has been studied at ambient temperature by the diffuse X-ray scattering technique. Both Yb and I atoms are disordered. In a unit cell of the average structure, the Yb atoms occupy two positions, 1/2, 1/2, 1/4 or 1/2, 1/2, 3/4, with occupancy 0.5. In the neighbouring unit cells in the (001) plane there is, however, a strong tendency towards an alternating distribution of ytterbium in positions shifted by Delta z = 1/2. The crystal structure of YPI consists of one-dimensional columnar stacks of [YbPc(2)(2/3+)](n) and of linear iodine chains [I(3)(-)](n). The modulation is commensurate since the period c(I) of iodine chains [I(3)(-)](n) in the [001] direction is equal to one-half of the period c of the [YbPc(2)(2/3+)](n) stacks. In the crystal structure, each stack of [YbPc(2)(2/3+)](n) may occur in two settings shifted by c/2 and each iodine chain in three settings shifted along [001] by one-third of the period c(I). The short-range order of iodine chains distributed over three settings results in a complicated pattern. Iodine chains of the same setting tend to form ribbons perpendicular to <100> and running along [001]. PMID:12149551

Krawczyk, J; Pietraszko, A; ?ukaszewicz, K

2002-08-01

328

MicroRNA-17-5p promotes chemotherapeutic drug resistance and tumour metastasis of colorectal cancer by repressing PTEN expression  

PubMed Central

Background: Colorectal cancer (CRC) is one of the most common cancers worldwide, especially in Western countries. Although chemotherapy is used as an adjuvant or as a palliative treatment, drug resistance poses a great challenge. This study intended to identify biomarkers as predictive factors for chemotherapy. Patients and methods: By microarray analysis, we studied miRNAs expression profiles in CRC patient, comparing chemoresistant and chemosensitive groups. The miRNAs of interest were validated and the impact on clinical outcomes was assessed in a cohort of 295 patients. To search for potential targets of these miRNAs, tissue samples were subject to in situ hybridization and immunohistochemistry analysis. Colorectal adenocarcinoma cells were also used for in vitro experimentation, where cellular invasiveness and drug resistance were examined in miRNA-transfected cells. Results: The expression level of miRNA-17-5p was found increased in chemoresistant patients. Significantly higher expression levels of miR-17-5p were found in CRC patients with distant metastases and higher clinical stages. Kaplan-Meier analysis showed that CRC patients with higher levels of miR-17-5p had reduced survival, especially in patients who had previously received chemotherapy. Overexpression of miR-17-5p promoted COLO205 cell invasiveness. We found that PTEN was a target of miR-17-5p in the colon cancer cells, and their context-specific interactions were responsible for multiple drug-resistance. Chemotherapy was found to increase the expression levels of miR-17-5p, which further repressed PTEN levels, contributing to the development of chemo-resistance. Conclusions: MiR-17-5p is a predictive factor for chemotherapy response and a prognostic factor for overall survival in CRC, which is due to its regulation of PTEN expression.

Wang, Lei; Hu, Jun; Jin, Tianru; Wang, Jianping; Yang, Burton B

2014-01-01

329

IDCS J1426.5+3508: DISCOVERY OF A MASSIVE, INFRARED-SELECTED GALAXY CLUSTER AT z = 1.75  

SciTech Connect

We report the discovery of an IR-selected massive galaxy cluster in the IRAC Deep Cluster Survey (IDCS). We present new data from the Hubble Space Telescope and the W. M. Keck Observatory that spectroscopically confirm IDCS J1426.5+3508 at z = 1.75. Moreover, the cluster is detected in archival Chandra data as an extended X-ray source, comprising 53 counts after the removal of point sources. We calculate an X-ray luminosity of L{sub 0.5-2keV} = (5.4 {+-} 1.2) Multiplication-Sign 10{sup 44} erg s{sup -1} within r = 60 arcsec ({approx}1 Mpc diameter), which implies M{sub 200,L{sub x}}= (5.3{+-}1.6) Multiplication-Sign 10{sup 14} M{sub Sun }. IDCS J1426.5+3508 appears to be an exceptionally massive cluster for its redshift.

Stanford, S. A.; Zeimann, Greg [Department of Physics, University of California, One Shields Avenue, Davis, CA 95616 (United States); Brodwin, M. [Department of Physics and Astronomy, University of Missouri, Kansas City, MO 64110 (United States); Gonzalez, Anthony H.; Mancone, C. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Stern, Daniel; Eisenhardt, P. R. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Dey, Arjun [NOAO, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Snyder, Gregory F., E-mail: stanford@physics.ucdavis.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-07-10

330

175 MeV Au{sup +13} ion irradiation induced structural and morphological modifications in zinc oxide thin films  

SciTech Connect

Thin films of ZnO were deposited, on Si substrates, using the RF-sputtering technique and irradiated by the 175 MeV Au{sup +13} beams. The structural changes were investigated by x-ray diffraction (XRD) measurements. The particle size found to increase with the increasing ion fluence up to 1 Multiplication-Sign 10{sup 12} ion/cm{sup 2}. At highest irradiation fluence of 5 Multiplication-Sign 10{sup 12} ion/cm{sup 2} the average particle size decreases. The Raman spectroscopy measurements were performed to understand the local phonon mode of the samples. The surface morphology of the as-deposited and irradiated thin films is measured by the Atomic Force Microscopy (AFM).

Singh, Devendra [Materials Science Research Laboratory, Department of Physics, S. V. College, Aligarh 202001, UP (India); Sharma, Aditya [Materials Science Research Laboratory, Department of Physics, S. V. College, Aligarh 202001, UP (India) and Department of Applied Sciences and Humanities, Krishna Institute of Engineering and Technology, Ghaziabad-201206, U.P. (India); Varshney, Mayora; Verma, K. D. [Materials Science Research Laboratory, Department of Physics, S. V. College, Aligarh 202001, UP (India) and Department of Applied Sciences and Humanities, Krishna Institute of Engineering and Technolog (India); Kumar, Shalendra [School of Nano and Advanced Materials Engineering, Changwon National University, 9 Sarim-dong, Changwon- 641-773 (Korea, Republic of)

2013-02-05

331

Nanoscale phase separation of antiferromagnetic order and superconductivity in K0.75Fe1.75Se2  

PubMed Central

We report an in-plane optical spectroscopy study on the iron-selenide superconductor K0.75Fe1.75Se2. The measurement revealed the development of a sharp reflectance edge below Tc at frequency much smaller than the superconducting energy gap on a relatively incoherent electronic background, a phenomenon which was not seen in any other Fe-based superconductors so far investigated. Furthermore, the feature could be noticeably suppressed and shifted to lower frequency by a moderate magnetic field. Our analysis indicates that this edge structure arises from the development of a Josephson-coupling plasmon in the superconducting condensate. Together with the transmission electron microscopy analysis, our study yields compelling evidence for the presence of nanoscale phase separation between superconductivity and magnetism. The results also enable us to understand various seemingly controversial experimental data probed from different techniques.

Yuan, R. H.; Dong, T.; Song, Y. J.; Zheng, P.; Chen, G. F.; Hu, J. P.; Li, J. Q.; Wang, N. L.

2012-01-01

332

Crystallization of Phase-Separated Pd41.25Ni41.25P17.5 BMGs  

NASA Astrophysics Data System (ADS)

Phase-separated Pd41.25Ni41.25P17.5 bulk metallic glasses (BMGs) were subjected to isothermal annealing at 613 K (340 °C) for different time periods, t, in the range of 0 ? t ? 8 hours. For 0 ? t ? 5 hours, crystalline precipitates, in the shape of spheres, appear and its density is more or less a linear function of t. They are randomly distributed in the amorphous matrix. For t ? 5 to 6 hours, the number density of the spherical crystalline precipitates increases rapidly. In addition, they are no longer distributed randomly in the phase-separated amorphous matrix. Clustering is displayed. Experimental results suggest that the clustering is due to cubic crystalline precipitates that start to appear when t ? 5 to 6 hours.

Wu, Z. D.; Lan, S.; Kui, H. W.

2014-05-01

333

IDCS J1426.5+3508: Cosmological Implications of a Massive, Strong Lensing Cluster at z = 1.75  

NASA Astrophysics Data System (ADS)

The galaxy cluster IDCS J1426.5+3508 at z = 1.75 is the most massive galaxy cluster yet discovered at z > 1.4 and the first cluster at this epoch for which the Sunyaev-Zel'Dovich effect has been observed. In this paper, we report on the discovery with Hubble Space Telescope imaging of a giant arc associated with this cluster. The curvature of the arc suggests that the lensing mass is nearly coincident with the brightest cluster galaxy, and the color is consistent with the arc being a star-forming galaxy. We compare the constraint on M 200 based upon strong lensing with Sunyaev-Zel'Dovich results, finding that the two are consistent if the redshift of the arc is z >~ 3. Finally, we explore the cosmological implications of this system, considering the likelihood of the existence of a strongly lensing galaxy cluster at this epoch in a ?CDM universe. While the existence of the cluster itself can potentially be accommodated if one considers the entire volume covered at this redshift by all current high-redshift cluster surveys, the existence of this strongly lensed galaxy greatly exacerbates the long-standing giant arc problem. For standard ?CDM structure formation and observed background field galaxy counts this lens system should not exist. Specifically, there should be no giant arcs in the entire sky as bright in F814W as the observed arc for clusters at z >= 1.75, and only ~0.3 as bright in F160W as the observed arc. If we relax the redshift constraint to consider all clusters at z >= 1.5, the expected number of giant arcs rises to ~15 in F160W, but the number of giant arcs of this brightness in F814W remains zero. These arc statistic results are independent of the mass of IDCS J1426.5+3508. We consider possible explanations for this discrepancy.

Gonzalez, Anthony H.; Stanford, S. Adam; Brodwin, Mark; Fedeli, Cosimo; Dey, Arjun; Eisenhardt, Peter R. M.; Mancone, Conor; Stern, Daniel; Zeimann, Greg

2012-07-01

334

A 63 element 1.75 dimensional ultrasound phased array for the treatment of benign prostatic hyperplasia  

PubMed Central

Background Prostate cancer and benign prostatic hyperplasia are very common diseases in older American men, thus having a reliable treatment modality for both diseases is of great importance. The currently used treating options, mainly surgical ones, have numerous complications, which include the many side effects that accompany such procedures, besides the invasive nature of such techniques. Focused ultrasound is a relatively new treating modality that is showing promising results in treating prostate cancer and benign prostatic hyperplasia. Thus this technique is gaining more attention in the past decade as a non-invasive method to treat both diseases. Methods In this paper, the design, construction and evaluation of a 1.75 dimensional ultrasound phased array to be used for treating prostate cancer and benign prostatic hyperplasia is presented. With this array, the position of the focus can be controlled by changing the electrical power and phase to the individual elements for electronically focusing and steering in a three dimensional volume. The array was designed with a maximum steering angle of ± 13.5° in the transverse direction and a maximum depth of penetration of 11 cm, which allows the treatment of large prostates. The transducer piezoelectric ceramic, matching layers and cable impedance have been designed for maximum power transfer to tissue. Results To verify the capability of the transducer for focusing and steering, exposimetry was performed and the results correlated well with the calculated field. Ex vivo experiments using bovine tissue were performed with various lesion sizes and indicated the capability of the transducer to ablate tissue using short sonications. Conclusion A 1.75 dimensional array, that overcame the drawbacks associated with one-dimensional arrays, has been designed, built and successfully tested. Design issues, such as cable and ceramic capacitances, were taken into account when designing this array. The final prototype overcame also the problem of generating grating lobes at unwanted locations by tapering the array elements.

Saleh, Khaldon Y; Smith, Nadine Barrie

2005-01-01

335

Decreased Sensitivity to Changes in the Concentration of Metal Ions as the Basis for the Hyperactivity of DtxR(E175K)  

SciTech Connect

The metal-ion-activated diphtheria toxin repressor (DtxR) is responsible for the regulation of virulence and other genes in Corynebacterium diphtheriae. A single point mutation in DtxR, DtxR(E175K), causes this mutant repressor to have a hyperactive phenotype. Mice infected with Mycobacterium tuberculosis transformed with plasmids carrying this mutant gene show reduced signs of the tuberculosis infection. Corynebacterial DtxR is able to complement mycobacterial IdeR and vice versa. To date, an explanation for the hyperactivity of DtxR(E175K) has remained elusive. In an attempt to address this issue, we have solved the first crystal structure of DtxR(E175K) and characterized this mutant using circular dichroism, isothermal titration calorimetry, and other biochemical techniques. The results show that although DtxR(E175K) and the wild type have similar secondary structures, DtxR(E175K) gains additional thermostability upon activation with metal ions, which may lead to this mutant requiring a lower concentration of metal ions to reach the same levels of thermostability as the wild-type protein. The E175K mutation causes binding site 1 to retain metal ion bound at all times, which can only be removed by incubation with an ion chelator. The crystal structure of DtxR(E175K) shows an empty binding site 2 without evidence of oxidation of Cys102. The association constant for this low-affinity binding site of DtxR(E175K) obtained from calorimetric titration with Ni(II) is K{sub a} = 7.6 {+-} 0.5 x 10{sup 4}, which is very similar to the reported value for the wild-type repressor, K{sub a} = 6.3 x 10{sup 4}. Both the wild type and DtxR(E175K) require the same amount of metal ion to produce a shift in the electrophoretic mobility shift assay, but unlike the wild type, DtxR(E175K) binding to its cognate DNA [tox promoter-operator (toxPO)] does not require metal-ion supplementation in the running buffer. In the timescale of these experiments, the Mn(II)-DtxR(E175K)-toxPO complex is insensitive to changes in the environmental cation concentrations. In addition to Mn(II), Ni(II), Co(II), Cd(II), and Zn(II) are able to sustain the hyperactive phenotype. These results demonstrate a prominent role of binding site 1 in the activation of DtxR and support the hypothesis that DtxR(E175K) attenuates the expression of virulence due to the decreased ability of the Me(II)-DtxR(E175K)-toxPO complex to dissociate at low concentrations of metal ions.

D’ Aquino, J. Alejandro; Denninger, Andrew R.; Moulin, Aaron G.; D’ Aquino, Katharine E.; Ringe, Dagmar; (Harvard-Med); (Brandeis)

2010-01-12

336

Studies on the Q175 Knock-in Model of Huntington's Disease Using Functional Imaging in Awake Mice: Evidence of Olfactory Dysfunction  

PubMed Central

Blood oxygen level dependent (BOLD) imaging in awake mice was used to identify differences in brain activity between wild-type, HETzQ175, and HOMzQ175 genotypes in response to the odor of almond. The study was designed to see how alterations in the huntingtin gene in a mouse model of Huntington’s disease would affect the perception and processing of almond odor, an evolutionarily conserved stimulus with high emotional and motivational valence. Moreover, the mice in this study were “odor naïve,” i.e., never having smelled almond or any nuts. Using a segmented, annotated MRI atlas of the mouse and computational analysis, 17 out of 116 brain regions were identified as responding differently to almond odor across genotypes. These regions included the glomerulus of the olfactory bulb, forebrain cortex, anterior cingulate, subiculum, and dentate gyrus of the hippocampus, and several areas of the hypothalamus. In many cases, these regions showed a gene-dose effect with HETzQ175 mice showing a reduction in brain activity from wild-type that is further reduced in HOMzQ175 mice. Conspicuously absent were any differences in brain activity in the caudate/putamen, thalamus, CA3, and CA1 of the hippocampus and much of the cortex. The glomerulus of the olfactory bulb in HOMzQ175 mice showed a reduced change in BOLD signal intensity in response to almond odor as compared to the other phenotypes suggesting a deficit in olfactory sensitivity.

Ferris, Craig F.; Kulkarni, Praveen; Toddes, Steven; Yee, Jason; Kenkel, William; Nedelman, Mark

2014-01-01

337

Ytterbium Optical Lattice Clock  

NASA Astrophysics Data System (ADS)

We report on an optical clock based on the ^1S0-^3P0 transition in neutral Yb atoms confined to a Stark shift-free optical lattice. Tight confinement of atoms to the Lamb-Dicke regime is shown to suppress Doppler- and recoil-related shifts, while the Stark shift-canceling technique eliminates the clock's first-order sensitivity to lattice intensity. Clocks based on magnetically-induced spectroscopy of ^174Yb (I=0) and state-resolved spectroscopy of ^171Yb (I=1/2) are demonstrated. Comparisons with other optical and microwave frequency standards via a self-referenced femtosecond frequency comb have enabled initial measurements of the absolute frequency and systematic effects with a fractional uncertainty of 10-15, a level that can be reached in 10 seconds of averaging time.

Lemke, Nathan; Barber, Zeb; Poli, Nicola; Oates, Chris; Hollberg, Leo

2008-05-01

338

IDCS J1426.5+3508: COSMOLOGICAL IMPLICATIONS OF A MASSIVE, STRONG LENSING CLUSTER AT z = 1.75  

SciTech Connect

The galaxy cluster IDCS J1426.5+3508 at z = 1.75 is the most massive galaxy cluster yet discovered at z > 1.4 and the first cluster at this epoch for which the Sunyaev-Zel'Dovich effect has been observed. In this paper, we report on the discovery with Hubble Space Telescope imaging of a giant arc associated with this cluster. The curvature of the arc suggests that the lensing mass is nearly coincident with the brightest cluster galaxy, and the color is consistent with the arc being a star-forming galaxy. We compare the constraint on M{sub 200} based upon strong lensing with Sunyaev-Zel'Dovich results, finding that the two are consistent if the redshift of the arc is z {approx}> 3. Finally, we explore the cosmological implications of this system, considering the likelihood of the existence of a strongly lensing galaxy cluster at this epoch in a {Lambda}CDM universe. While the existence of the cluster itself can potentially be accommodated if one considers the entire volume covered at this redshift by all current high-redshift cluster surveys, the existence of this strongly lensed galaxy greatly exacerbates the long-standing giant arc problem. For standard {Lambda}CDM structure formation and observed background field galaxy counts this lens system should not exist. Specifically, there should be no giant arcs in the entire sky as bright in F814W as the observed arc for clusters at z {>=} 1.75, and only {approx}0.3 as bright in F160W as the observed arc. If we relax the redshift constraint to consider all clusters at z {>=} 1.5, the expected number of giant arcs rises to {approx}15 in F160W, but the number of giant arcs of this brightness in F814W remains zero. These arc statistic results are independent of the mass of IDCS J1426.5+3508. We consider possible explanations for this discrepancy.

Gonzalez, Anthony H.; Fedeli, Cosimo; Mancone, Conor [Department of Astronomy, University of Florida, Gainesville, FL 32611-2055 (United States); Stanford, S. Adam; Zeimann, Greg [Department of Physics, University of California, One Shields Avenue, Davis, CA 95616 (United States); Brodwin, Mark [Department of Physics, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States); Dey, Arjun [NOAO, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Eisenhardt, Peter R. M.; Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

2012-07-10

339

MicroRNAs 17-5p–20a–106a control monocytopoiesis through AML1 targeting and M-CSF receptor upregulation  

Microsoft Academic Search

We investigated the role of microRNAs (miRNA) 17-5p, 20a and 106a in monocytic differentiation and maturation. In unilineage monocytic culture generated by haematopoietic progenitor cells these miRNAs are downregulated, whereas the transcription factor acute myeloid leukaemia-1 (AML1; also known as Runt-related transcription factor 1, Runx1) is upregulated at protein but not mRNA level. As miRNAs 17-5p, 20a and 106a bind

Elvira Pelosi; Paolo Greco; Serena Racanicchi; Ugo Testa; Francesca Liuzzi; Carlo M. Croce; Ercole Brunetti; Francesco Grignani; Laura Fontana; Cesare Peschle

2007-01-01

340

Regulation of adenovirus and cellular gene expression and of cellular transformation by the E1B-encoded 175-amino-acid protein.  

PubMed Central

Mutants of type 5 adenovirus that fail to express the E1B-gene-encoded 175-amino-acid (175R) protein are unable to morphologically transform primary or continuous cultures of rat embryo fibroblast cells. This phenotype could result from a direct effect of this E1B polypeptide (along with E1A polypeptides) on cellular gene expression resulting in a pathway leading to altered cell growth or from an indirect role of the 175R protein made possible by its ability to modulate viral early-gene (most likely E1A) expression. To distinguish between these two models, viruses were constructed that expressed the individual E1A 13S and 12S genes in the presence of either the E1B 175R or 495R protein. Regardless of the E1A gene product that was expressed, viruses that failed to express the E1B 175R protein were transformation defective. Additional studies suggest that the E1A 289R protein and E1B 495R protein function in a common pathway leading to the establishment of the transformed cell. We also observe that E3 gene expression by viruses that fail to express the E1A 289R protein affects the efficiency of focus formation. When tested in both nonpermissive CREF cells and permissive HeLa cells, the lack of 175R protein expression appeared to have no effect (a transient twofold decrease in E1A mRNA accumulation was observed in CREF cells) on viral early-gene expression. These results suggest that the initiation of the transformed cell phenotype occurs because of some interaction in a common pathway between the viral E1A proteins and E1B 175R protein. Furthermore, we have shown that the E1B 175R protein does not enhance the rate of transcription initiation from the mouse immunoglobulin heavy chain gene promoter when these sequences are localized on a viral genome, and it does not diminish the ability of the E1A proteins to decrease the rate of enhancer-dependent transcription. Images

Herbst, R S; Hermo, H; Fisher, P B; Babiss, L E

1988-01-01

341

On deformation twinning in a 17.5%Mn-TWIP steel: A physically-based phenomenological model  

SciTech Connect

TWinning Induced Plasticity (TWIP) steel is a typical representative of the 2nd generation of advanced high strength steel (AHSS) which exhibits a combination of high strength and excellent ductility due to the twinning mechanisms. This paper discusses the principal features of deformation twinning in faced-centered cubic austenitic steels and shows how a physiscally-based macroscopic model can be derived from microscopic considerations. In fact, a dislocation-based phenomenological model, with internal state variables such as dislocation density and micro-twins volume fraction representing the microstructure evolution during deformation process, is proposed to describe the deformation behavior of TWIP steels. The contribution of this work is the incorporation of a physically-based twin’s nucleation and volume fraction evolution model in a conventional dislocation-based approach. Microstructural level investigations, using scanning electron microscope (SEM) and transmission electron microscope (TEM) techniques, for the TWIP steel Fe–17.5 wt.% Mn–1.4 wt.% Al- 0.56 wt.% C, are used to validate and verify modeling assumptions. The model could be regarded as a semi-phenomenological approach with sufficient links between microstructure and overall properties and therefore offers good predictive capabilities. Its simplicity also allows a modular implementation in finite element-based metal forming simulations.

Soulami, Ayoub; Choi, Kyoo Sil; Shen, Y. F.; Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.

2011-01-25

342

The comparison of doses measured by radiochromic films and semiconductor detector in a 175MeV proton beam.  

PubMed

We wanted to verify the response of radiochromic films in a 175MeV clinical proton beam used at the Joint Institute for Nuclear Research in Dubna against doses measured using semiconductor detectors and compare the results with published data from other centres. Radiochromic films (RCFs) MD-55 and a Vidar VXR-16 scanner were used. The films were irradiated in an unmodulated proton beam and with a beam modulated with a bolus and a ridge filter. Obtained dose distributions were compared with dose distributions measured with a Si-semiconductor detector. For the unmodulated beam the difference between the RCF and the semiconductor detector was 12% in the Bragg peak top. For the modulated beam the difference inside the spread-out Bragg peak region was 4%. Observed deviations between doses measured with RCF and Si-detector outside the Bragg peak were caused by the inhomogeneity of radiochromic emulsion. In the Bragg peak region the RCF doses were lower than those measured by semiconductors. The results were in agreement with published data from other proton therapy centres. PMID:18694653

Mumot, Marta; Mytsin, Gennady V; Molokanov, Alexander G; Malicki, Julian

2009-09-01

343

HYDROGEN EFFECTS ON FRACTURE TOUGHNESS OF TYPE 316L STAINLESS STEEL FROM 175 K TO 425 K  

SciTech Connect

The effects of hydrogen on the fracture-toughness properties of Type 316L stainless steel from 175 K to 425 K were measured. Fracture-toughness samples were fabricated from Type 316L stainless steel forgings and hydrogen-charged with hydrogen at 34 MPa and 623 K for two weeks prior to testing. The effect of hydrogen on the J-Integral vs. crack extension behavior was measured at various temperatures by fracturing non-charged and hydrogen-charged samples in an environmental chamber. Hydrogen-charged steels had lower toughness values than non-charged ones, but still retained good toughness properties. The fracture-toughness values of hydrogen-charged samples tested near ambient temperature were about 70% of non-charged values. For hydrogen-charged samples tested at 225 K and 425 K, the fracture-toughness values were 50% of the non-charged values. In all cases, fracture occurred by microvoid nucleation and coalescence, although the hydrogen-charged samples had smaller and more closely spaced microvoids. The results suggest that hydrogen effects on toughness are greater at 225 K than they are at ambient temperature because of strain-induced martensite formation. At 425 K, the hydrogen effects on toughness are greater than they are at ambient temperature because of the higher mobility of hydrogen.

Morgan, M; Glenn Chapman, G

2009-05-04

344

Comparative in vivo efficiencies of hand-washing agents against hepatitis A virus (HM-175) and poliovirus type 1 (Sabin).  

PubMed Central

The abilities of 10 hygienic hand-washing agents and tap water (containing approximately 0.5 ppm of free chlorine) to eliminate strain HM-175 of hepatitis A virus (HAV) and poliovirus (PV) type 1 (Sabin) were compared by using finger pad and whole-hand protocols with three adult volunteers. A mixture of the two viruses was prepared in a 10% suspension of feces, and 10 microliters of the mixture was placed on each finger pad. The inoculum was allowed to dry for 20 min, and the contaminated area was exposed to a hand-washing agent for 10 s, rinsed in tap water, and dried with a paper towel. In the whole-hand protocol, the hands were contaminated with 0.5 ml of the virus mixture, exposed for 10 s to a hand-washing agent, washed, and dried as described above. Tryptose phosphate broth was used to elute any virus remaining on the finger pads or hands. One part of the eluate was assayed directly for PV with FRhK-4 cells, while the other part was first treated with a PV-neutralizing serum and then assayed for HAV with the same cell line. The results are reported as mean percentages of reduction in PFU compared with the amount of infectious virus detectable after initial drying.(ABSTRACT TRUNCATED AT 250 WORDS)

Mbithi, J N; Springthorpe, V S; Sattar, S A

1993-01-01

345

High-pressure synthesis, crystal structure, and structural relationship of the first ytterbium fluoride borate Yb{sub 5}(BO{sub 3}){sub 2}F{sub 9}  

SciTech Connect

Yb{sub 5}(BO{sub 3}){sub 2}F{sub 9} was synthesized under high-pressure/high-temperature conditions in a Walker-type multianvil apparatus at 7.5 GPa and 1100 deg. C, representing the first known ytterbium fluoride borate. The compound exhibits isolated BO{sub 3}-groups next to ytterbium cations and fluoride anions, showing a structure closely related to the other known rare-earth fluoride borates RE{sub 3}(BO{sub 3}){sub 2}F{sub 3} (RE=Sm, Eu, Gd) and Gd{sub 2}(BO{sub 3})F{sub 3}. Monoclinic Yb{sub 5}(BO{sub 3}){sub 2}F{sub 9} crystallizes in space group C2/c with the lattice parameters a=2028.2(4) pm, b=602.5(2) pm, c=820.4(2) pm, and beta=100.63(3){sup o} (Z=4). Three different ytterbium cations can be identified in the crystal structure, each coordinated by nine fluoride and oxygen anions. None of the five crystallographically independent fluoride ions is coordinated by boron atoms, solely by trigonally-planar arranged ytterbium cations. In close proximity to the above mentioned compounds RE{sub 3}(BO{sub 3}){sub 2}F{sub 3} (RE=Sm, Eu, Gd) and Gd{sub 2}(BO{sub 3})F{sub 3}, Yb{sub 5}(BO{sub 3}){sub 2}F{sub 9} can be described via alternating layers with the formal compositions 'YbBO{sub 3}' and 'YbF{sub 3}' in the bc-plane. - Graphical abstract: High-pressure/high-temperature synthesis (multianvil technique) led to the first ytterbium fluoride borate Yb{sub 5}(BO{sub 3}){sub 2}F{sub 9}, built up from isolated BO{sub 3}-groups. The compound shows structural relations to the known rare-earth fluoride borates RE{sub 3}(BO{sub 3}){sub 2}F{sub 3} (RE=Sm, Eu, Gd) and Gd{sub 2}(BO{sub 3})F{sub 3}.

Haberer, Almut [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria); Huppertz, Hubert, E-mail: hubert.huppertz@uibk.ac.a [Institut fuer Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universitaet Innsbruck, Innrain 52a, A-6020 Innsbruck (Austria)

2009-04-15

346

New [ONOO]-type amine bis(phenolate) ytterbium(II) and -(III) complexes: synthesis, structure, and catalysis for highly heteroselective polymerization of rac-lactide.  

PubMed

Two divalent ytterbium (Yb(II)) complexes, 1 and 2, supported by new [ONOO]-type amine bis(phenolate) ligands L(a,b) were synthesized in good yield by an amine elimination reaction of Yb(II)(N(SiMe3)2)2(TMEDA) (TMEDA = tetramethylethylenediamine) with one equivalent of the ligand precursor. X-ray structural determination showed complexes 1 and 2 both have a monomeric structure. Each adopts distorted octahedral coordination geometry around the six-coordinate Yb(II) ion. Two new trivalent ytterbium (Yb(III)) aryloxide complexes, 4 and 5, bearing [ONOO]-type amine bis(phenolate) ligands L(c) and L(d) were prepared by double-protonation reaction of Yb(C5H5)3THF with one equivalent of the ligand precursor, then one equivalent of phenol. Complex 4 has a symmetric dimeric structure with a Yb2O2 core bridging through the oxygen atoms of the OC6H4-4-CH3 groups. Complex 5 is a THF-solvated monomer. Each six-coordinated Yb(III) ion in both complexes adopts a distorted octahedron. All the complexes synthesized together with the known Yb(II) complex 3 were evaluated in the ring-opening polymerization (ROP) of rac-lactide (rac-LA). Complexes 1 and 4 were found to be extremely active for controlled ROP of rac-LA, as judged by narrow molar mass distributions (Mw/Mn: 1.07-1.16 for complex 1 and 1.07-1.10 for complex 4) and experimental molar mass Mn,exp values in good agreement with theoretic Mn,calcd values calculated on a single PLA chain produced per metal center of initiator. Complex 5 is less controlled. Complexes 1, 4, and 5 exhibited the same high stereoselectivity to give heterotactic polylactide with a Pr (probability of racemic enchainment of monomer units) ranging from 0.97 to 0.99. Dramatic decreases in activity and stereoselectivity were found for complexes 2 (Pr = 0.82) and 3 (Pr = 0.67), indicating the framework of L in the unit of [YbL] is crucial for determining activity and stereoselectivity of either Yb(II) or Yb(III) complexes. PMID:24313811

Yang, Sheng; Nie, Kun; Zhang, Yong; Xue, Mingqiang; Yao, Yingming; Shen, Qi

2014-01-01

347

Anisotropy of mobility ratio between electron and hole along different orientations in ReGe{sub x}Si{sub 1.75-x} thermoelectric single crystals  

SciTech Connect

It was recently found that ReSi{sub 1.75} based semiconductor single crystals can be of either p or n type with a fixed composition, just depending on their different crystal orientations. To investigate the mechanism of this interesting phenomenon, we grow ReGe{sub x}Si{sub 1.75-x} (x=0.02 and 0.04) single crystals with a floating zone method with radiation heating. The Seebeck coefficient and electric resistivity of these samples are measured along [100] and [001], respectively. The conduction mechanism is of p type along [100] and of n type along [001], like binary ReSi{sub 1.75}, in the temperature range 50 to 800 deg. C. The mobility ratio between electron and hole is calculated from the Seebeck coefficient data and it is highly anisotropic along two different orientations (about 0.4 to 0.6 along [100] while 4 to 5 along [001] direction), giving rise to the orientation-dependent conduction sign reversal phenomenon observed in ReSi{sub 1.75}.

Gu, J.-J. [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200030 (China); Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501 (Japan); Oh, M.-W.; Inui, H. [Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501 (Japan); Zhang, D. [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200030 (China)

2005-03-15

348

Inclusive scattering results from the Fermilab Single Arm Spectrometer. [100 to 175 GeV\\/c, cross sections, power-law behavior, multiplicity  

Microsoft Academic Search

Results are presented on the inclusive scattering process a + p ..-->.. c + X where a and c are any of ..pi..\\/sup + -\\/, K\\/sup + -\\/, p or anti p. The data were taken at 100 and 175 GeV\\/c incident momentum using the Fermilab Single Arm Spectrometer. A vertex detector was also used to measure the associated charged

D. Cutts; R. Dulude; R. E. Lanou

1978-01-01

349

ENVIRONMENTAL TECHNOLOGY VERIFICATION, TEST REPORT OF CONTROL OF BIOAEROSOLS IN HVAC SYSTEMS:AAF INTERNATIONAL, PERFECTPLEAT ULTRA, 175-102-863  

EPA Science Inventory

The Environmental Technology Verification report discusses the technology and performance of the PerfectPleat Ultra 175-102-863 air filter for dust and bioaerosol filtration manufactured by AAF International. The pressure drop across the filter was 112 Pa clean and 229 Pa dust lo...

350

Evaluation of Microstructure of a 6092 Al-17.5 Volume Percent SiC Particle Reinforced Composite Using Electron Backscatter Pattern (EBSP) Analysis Methods.  

National Technical Information Service (NTIS)

Microtexture and grain boundary misorientation data were obtained for a 6092 Al-17.5 volume percent SiC particle reinforced material as a function of processing history. Computer aided electron backscatter pattern (EBSP) analysis methods in a scanning ele...

J. J. Markovich

1998-01-01

351

Is BDE-175 an important enough component of commercial octabromodiphenyl ether mixtures to be listed in Annex A of the Stockholm Convention?  

PubMed

Commercial octabromodiphenyl ether mixtures, containing hexabromodiphenyl ethers and heptabromodiphenyl ethers were listed in Annex A of the Stockholm Convention on May 2009 (Fourth Conference of the Parties) (UNEP, 2009a). Four compounds are specifically mentioned: 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153), 2,2',4,4',5,6'-hexabromodiphenyl ether (BDE-154), 2,2',3,3',4,5',6-heptabromodiphenyl ether (BDE-175), and 2,2',3,4,4',5',6-heptabromodiphenyl ether (BDE-183). Presumably they were identified as key components of commercial mixtures and found to be present in environmental samples. However, since BDE-175 and BDE-183 co-elute on common HRGC columns, the presence of BDE-175 as an important component in technical octa-BDE mixtures has not been illustrated. The successful HRGC/LRMS separation of a 1:1 mixture of BDE-175 and BDE-183, as well as (1)H NMR analysis of technical material, has allowed us to confirm that this congener is not present in technical products (e.g. Great Lakes DE-79™) in quantifiable amounts. PMID:21122891

Konstantinov, Alexandre; Chittim, Brock; Potter, David; Klein, Jeffery; Riddell, Nicole; McCrindle, Robert

2011-01-01

352

41 CFR 302-9.175 - When I am authorized to transport a POV, including a replacement POV, to my post of duty...  

Code of Federal Regulations, 2013 CFR

...POV, to my post of duty subsequent to the time of my assignment to that post of duty... Pov Transportation Subsequent to the Time of Assignment § 302-9.175 When...to my post of duty subsequent to the time of my assignment to that post of...

2013-07-01

353

Correlation of missions 191, 51M and helicopter photography. [aerial photography and mapping of three areas in Test Site 175 in Texas  

NASA Technical Reports Server (NTRS)

The data obtained during aerial photography flights using a helicopter are presented. The areas photographed are identified as three areas within Test Site 175: (1) Rosenberg, (2) Houston Ship Channel/Trinity Bay, and (3) the Somerville Dam. Data are presented in the form of charts. Reproductions of the aerial photographs are included.

Bryan, B. A.; Tunnel, S. H.

1972-01-01

354

MiR-17-5p Impairs Trafficking of H-ERG K+ Channel Protein by Targeting Multiple ER Stress-Related Chaperones during Chronic Oxidative Stress  

PubMed Central

Background To investigate if microRNAs (miRNAs) play a role in regulating h-ERG trafficking in the setting of chronic oxidative stress as a common deleterious factor for many cardiac disorders. Methods We treated neonatal rat ventricular myocytes and HEK293 cells with stable expression of h-ERG with H2O2 for 12 h and 48 h. Expression of miR-17-5p seed miRNAs was quantified by real-time RT-PCR. Protein levels of chaperones and h-ERG trafficking were measured by Western blot analysis. Luciferase reporter gene assay was used to study miRNA and target interactions. Whole-cell patch-clamp techniques were employed to record h-ERG K+ current. Results H-ERG trafficking was impaired by H2O2 after 48 h treatment, accompanied by reciprocal changes of expression between miR-17-5p seed miRNAs and several chaperones (Hsp70, Hsc70, CANX, and Golga2), with the former upregulated and the latter downregulated. We established these chaperones as targets for miR-17-5p. Application miR-17-5p inhibitor rescued H2O2-induced impairment of h-ERG trafficking. Upregulation of endogenous by H2O2 or forced miR-17-5p expression either reduced h-ERG current. Sequestration of AP1 by its decoy molecule eliminated the upregulation of miR-17-5p, and ameliorated impairment of h-ERG trafficking. Conclusions Collectively, deregulation of the miR-17-5p seed family miRNAs can cause severe impairment of h-ERG trafficking through targeting multiple ER stress-related chaperones, and activation of AP1 likely accounts for the deleterious upregulation of these miRNAs, in the setting of prolonged duration of oxidative stress. These findings revealed the role of miRNAs in h-ERG trafficking, which may contribute to the cardiac electrical disturbances associated with oxidative stress.

Wang, Qi; Hu, Weina; Lei, Mingming; Wang, Yong; Yan, Bing; Liu, Jun; Zhang, Ren; Jin, Yuanzhe

2013-01-01

355

miR-17-5p Downregulation Contributes to Paclitaxel Resistance of Lung Cancer Cells through Altering Beclin1 Expression.  

PubMed

Non- small- cell lung cancer (NSCLC) is one of the most leading causes of cancer-related deaths worldwide. Paclitaxel based combination therapies have long been used as a standard treatment in aggressive NSCLCs. But paclitaxel resistance has emerged as a major clinical problem in combating non-small-cell lung cancer and autophagy is one of the important mechanisms involved in this phenomenon. In this study, we used microRNA (miRNA) arrays to screen differentially expressed miRNAs between paclitaxel sensitive lung cancer cells A549 and its paclitaxel-resistant cell variant (A549-T24). We identified miR-17-5p was one of most significantly downregulated miRNAs in paclitaxel-resistant lung cancer cells compared to paclitaxel sensitive parental cells. We found that overexpression of miR-17-5p sensitized paclitaxel resistant lung cancer cells to paclitaxel induced apoptotic cell death. Moreover, in this report we demonstrated that miR-17-5p directly binds to the 3'-UTR of beclin 1 gene, one of the most important autophagy modulator. Overexpression of miR-17-5p into paclitaxel resistant lung cancer cells reduced beclin1 expression and a concordant decease in cellular autophagy. We also observed similar results in another paclitaxel resistant lung adenosquamous carcinoma cells (H596-TxR). Our results indicated that paclitaxel resistance of lung cancer is associated with downregulation of miR-17-5p expression which might cause upregulation of BECN1 expression. PMID:24755562

Chatterjee, Abhisek; Chattopadhyay, Dhrubajyoti; Chakrabarti, Gopal

2014-01-01

356

miR-17-5p Downregulation Contributes to Paclitaxel Resistance of Lung Cancer Cells through Altering Beclin1 Expression  

PubMed Central

Non- small- cell lung cancer (NSCLC) is one of the most leading causes of cancer-related deaths worldwide. Paclitaxel based combination therapies have long been used as a standard treatment in aggressive NSCLCs. But paclitaxel resistance has emerged as a major clinical problem in combating non-small-cell lung cancer and autophagy is one of the important mechanisms involved in this phenomenon. In this study, we used microRNA (miRNA) arrays to screen differentially expressed miRNAs between paclitaxel sensitive lung cancer cells A549 and its paclitaxel-resistant cell variant (A549-T24). We identified miR-17-5p was one of most significantly downregulated miRNAs in paclitaxel-resistant lung cancer cells compared to paclitaxel sensitive parental cells. We found that overexpression of miR-17-5p sensitized paclitaxel resistant lung cancer cells to paclitaxel induced apoptotic cell death. Moreover, in this report we demonstrated that miR-17-5p directly binds to the 3?-UTR of beclin 1 gene, one of the most important autophagy modulator. Overexpression of miR-17-5p into paclitaxel resistant lung cancer cells reduced beclin1 expression and a concordant decease in cellular autophagy. We also observed similar results in another paclitaxel resistant lung adenosquamous carcinoma cells (H596-TxR). Our results indicated that paclitaxel resistance of lung cancer is associated with downregulation of miR-17-5p expression which might cause upregulation of BECN1 expression.

Chatterjee, Abhisek; Chattopadhyay, Dhrubajyoti; Chakrabarti, Gopal

2014-01-01

357

Analysis of patterns and treatment strategies for mandibular condyle fractures: review of 175 condyle fractures with review of literature.  

PubMed

This study aims to evaluate incidence, patterns and epidemiology of mandibular condylar fractures (MCF) to propose a treatment strategy for managing MCF and analyze the factors which influence the outcome. One hundred and seventy-five MCF's were evaluated over a four year period and their pattern was recorded in terms of displacement, level of fracture, age of incidence and dental occlusion. Of the 2,718 facial bone fractures, MCF incidence was the third most common at 18.39 %. Of 175 MCF 58.8 % were unilateral and 41.12 % were bilateral. 67 % of bilateral fractures and 43.8 % of unilateral fractures were associated with midline symphysis and contralateral parasymphysis fractures respectively. Most of the MCF was seen in the age group of above 16 years and 50 % of them were at subcondylar level (below the neck of the condyle). Majority of MCF sustained due to inter personal violence were undisplaced (72.7 %) and contrary to this majority of MCF sustained during road traffic accident were displaced. 62.9 % of total fractures required open reduction and rigid fixation and 37.1 % were managed with closed reduction. 80 % of MCF managed with closed reduction were in the age group of below 16 years. From this study it can be concluded that the treatment algorithm proposed for managing MCF is reliable and easy to adopt. We observed that absolute indication for open reduction of MCF is inability to achieve satisfactory occlusion by closed method and absolute contraindication for open reduction is condylar head fracture irrespective of the age of the patient. PMID:24431859

Reddy, N Viveka V; Reddy, P Bhaskar; Rajan, Ritesh; Ganti, Srinivas; Jhawar, D K; Potturi, Abhinand; Pradeep

2013-09-01

358

Amino acid and hexosamine composition and flux of sinking particulate matter in the equatorial Pacific at 175°E longitude  

NASA Astrophysics Data System (ADS)

Sinking matter collected by sediment traps, which were deployed in the equatorial Pacific Ocean at 175°E for about 11 months during 1992-1993, were analyzed for their flux and labile components in terms of amino acids and hexosamines. The samples provided a temporal resolution of 15 days and were collected from 1357 (shallow trap) and 4363 m (deep trap) depths where sea floor depth was 4880 m. Particle flux along with major components (carbonate, organic matter, biogenic opal and lithogenic material) and amino acid parameters showed distinct temporal variations, which were more pronounced in the shallow trap relative to deep trap. A coupling between the fluxes in the shallow and deep traps was more evident during the period of maximum particle flux, which seems to be connected with the short reappearance of non-El Niño conditions in equatorial Pacific during the 1991-1993 El Niño event. The biogeochemical indicators C/N, Asp/Bala, Glu/Gaba, Bala+Gaba mol%, THAA-C% and THAA-N% implied that the increase in sinking flux was associated with upwelling and enhanced surface production. Degradation of sinking particulate organic matter between the shallow and deep traps was also evident. Occasionally higher mass and major component fluxes in the deep trap relative to the shallow trap are attributed to contribution of resuspended particulates from sea floor (nepheloid layer) or to laterally advected particulates from nearby areas. Carbonate and opal composition of the sinking flux showed a predominance of calcareous plankton; however, Asp/Gly mol ratio and Ser+Thr mol% indicated enhanced occurrence of diatoms during the periods of higher flux.

Gupta, Lallan Prasad; Kawahata, Hodaka

2000-10-01

359

Trepanning drilling of stainless steel using a high-power Ytterbium-doped fiber ultrafast laser: influence of pulse duration on hole geometry and processing quality  

NASA Astrophysics Data System (ADS)

Percussion drilling is a well-established technique for several applicative markets such as for aircraft and watch industries. Lamp pumped solid state lasers and more recently fiber lasers, operating in millisecond or nanosecond regimes, are classically used for these applications. However, due to their long pulse duration, these technologies are not suitable for emerging applicative market such as fuel injectors for automotive industry. Only the ultrashort laser technology, combined with special drilling optics like trepanning head, has the potential to fulfill the needs for this new market in terms of processing quality, custom-shape capabilities and short drilling time. Although numerous papers dealing with percussion drilling have been reported in the literature, only few papers are dedicated to trepanning drilling. In this context, we present some results on the influence of pulse duration on gas-assisted laser drilling of stainless steel using a trepanning head and a high power Ytterbium doped fiber ultrafast laser (20W). The influence of pulse energy (7- 64?J), fluence (3-25 J/cm2), drilling time (1-20s), processing gas pressure and drilling strategy will be discussed as well.

Lopez, John; Dijoux, Mathieu; Devillard, Raphael; Faucon, Marc; Kling, Rainer

2014-03-01

360

Observation and Absolute Frequency Measurements of the {sup 1}S{sub 0}-{sup 3}P{sub 0} Optical Clock Transition in Neutral Ytterbium  

SciTech Connect

We report the direct excitation of the highly forbidden (6s{sup 2}){sup 1}S{sub 0}{r_reversible}(6s6p){sup 3}P{sub 0} optical transition in two odd isotopes of neutral ytterbium. As the excitation laser frequency is scanned, absorption is detected by monitoring the depletion from an atomic cloud at {approx}70 {mu}K in a magneto-optical trap. The measured frequency in {sup 171}Yb (F=1/2) is 518 295 836 591.6{+-}4.4 kHz. The measured frequency in {sup 173}Yb (F=5/2) is 518 294 576 847.6{+-}4.4 kHz. Measurements are made with a femtosecond-laser frequency comb calibrated by the National Institute of Standards and Technology cesium fountain clock and represent nearly a 10{sup 6}-fold reduction in uncertainty. The natural linewidth of these J=0 to J=0 transitions is calculated to be {approx}10 mHz, making them well suited to support a new generation of optical atomic clocks based on confinement in an optical lattice.

Hoyt, C.W.; Barber, Z.W.; Oates, C.W.; Fortier, T.M.; Diddams, S.A.; Hollberg, L. [National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305 (United States)

2005-08-19

361

Versatile ytterbium ion trap experiment for operation of scalable ion-trap chips with motional heating and transition-frequency measurements  

SciTech Connect

We present the design and operation of an ytterbium ion trap experiment with a setup offering versatile optical access and 90 electrical interconnects that can host advanced surface and multilayer ion trap chips mounted on chip carriers. We operate a macroscopic ion trap compatible with this chip carrier design and characterize its performance, demonstrating secular frequencies >1 MHz, and trap and cool nearly all of the stable isotopes, including {sup 171}Yb{sup +} ions, as well as ion crystals. For this particular trap we measure the motional heating rate and observe an {proportional_to}1/{omega}{sup 2} behavior for different secular frequencies {omega}. We also determine a spectral noise density S{sub E}(1 MHz)=3.6(9)x10{sup -11} V{sup 2} m{sup -2} Hz{sup -1} at an ion electrode spacing of 310(10) {mu}m. We describe the experimental setup for trapping and cooling Yb{sup +} ions and provide frequency measurements of the {sup 2}S{sub 1/2{r_reversible}}{sup 2}P{sub 1/2} and {sup 2}D{sub 3/2{r_reversible}}{sup 3}D[3/2]{sub 1/2} transitions for the stable {sup 170}Yb{sup +}, {sup 171}Yb{sup +}, {sup 172}Yb{sup +}, {sup 174}Yb{sup +}, and {sup 176}Yb{sup +} isotopes which are more precise than previously published work.

McLoughlin, James J.; Nizamani, Altaf H.; Siverns, James D.; Sterling, Robin C.; Hughes, Marcus D.; Lekitsch, Bjoern; Stein, Bjoern; Weidt, Seb; Hensinger, Winfried K. [Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH (United Kingdom)

2011-01-15

362

High-efficiency ytterbium-free erbium-doped all-glass double cladding silicate glass fiber for resonantly-pumped fiber lasers.  

PubMed

A highly efficient ytterbium-free erbium-doped silicate glass fiber has been developed for high-power fiber laser applications at an eye-safe wavelength near 1.55 ?m. Our preliminary experiments show that high laser efficiency can be obtained from a relatively short length of the gain fiber when resonantly pumped at 1535 nm in both core- and cladding-pumping configurations. With a core-pumping configuration as high as 75%, optical-to-optical efficiency and 4 W output power were obtained at 1560 nm from a 1 m long gain fiber. When using a cladding-pumping configuration, approximately 13 W output power with 67.7% slope efficiency was demonstrated from a piece of 2 m long fiber. The lengths of silicate-based gain fiber are much shorter than their silica-based counterparts used in other experiments, which is significantly important for high-power narrow-band and/or pulsed laser applications. PMID:24514181

Qiang, Zexuan; Geng, Jihong; Luo, Tao; Zhang, Jun; Jiang, Shibin

2014-02-01

363

1.06 ?m Q-switched ytterbium-doped fiber laser using few-layer topological insulator Bi?Se? as a saturable absorber.  

PubMed

Passive Q-switching of an ytterbium-doped fiber (YDF) laser with few-layer topological insulator (TI) is, to the best of our knowledge, experimentally demonstrated for the first time. The few-layer TI: Bi?Se? (2-4 layer thickness) is firstly fabricated by the liquid-phase exfoliation method, and has a low saturable optical intensity of 53 MW/cm² measured by the Z-scan technique. The optical deposition technique is used to induce the few-layer TI in the solution onto a fiber ferrule for successfully constructing the fiber-integrated TI-based saturable absorber (SA). By inserting this SA into the YDF laser cavity, stable Q-switching operation at 1.06 ?m is achieved. The Q-switched pulses have the shortest pulse duration of 1.95 ?s, the maximum pulse energy of 17.9 nJ and a tunable pulse-repetition-rate from 8.3 to 29.1 kHz. Our results indicate that the TI as a SA is also available at 1 ?m waveband, revealing its potential as another broadband SA (like graphene). PMID:24514504

Luo, Zhengqian; Huang, Yizhong; Weng, Jian; Cheng, Huihui; Lin, Zhiqing; Xu, Bin; Cai, Zhiping; Xu, Huiying

2013-12-01

364

Spectra, temporal structure, and angular directivity of laser radiation of a Yb:YAG crystal and ytterbium glass pumped by low-coherence radiation from a F{sub 2}{sup +}:LiF colour centre laser  

SciTech Connect

By focusing radiation from a F{sub 2}{sup +}:LiF colour centre laser (emitting in the range from 0.89 to 0.95 {mu}m) on plates of a Yb:YAG crystal with the 20% concentration of Yb and of ytterbium glass with the 10% concentration of Yb, we observed nanosecond radiation pulses of Yb{sup 3+} ions in the spectral region from 1.00 to 1.06 {mu}m with the spectral width up to 20 nm in Yb:YAG and up to 50 nm in the ytterbium glass. Lasing appeared in the active medium in the region of excitation of the SBS of pump radiation with a diameter less than 200 {mu}m. The angular divergence of the broadband laser radiation (10{sup -3}-10{sup -4} rad) was one-two orders of magnitude smaller than the diffraction limit. The mechanism of generation of short broadband high-directional laser pulses in the spatial structure of thin layers with inversion produced in the region of propagation of an intense acoustic wave in the medium is discussed. The interpretation of experimental data on the angular divergence of radiation is based on a new concept of the spatial distribution of the electromagnetic field of a photon not in the form of a travelling wave but with the field structures located in fixed positions along the propagation direction. The features of the temporal picture and narrowband lasing spectra of Yb:YAG and ytterbium glass in a resonator upon relaxation of the SBS excitation region in the active medium are considered. The possibility of diagnostics of medium parameters using the shift of spectra of the lasing at the resonator modes in different sites of the SBS excitation region is discussed. (active media. lasers)

Bykovskii, N E; Senatsky, Yu V [P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2008-09-30

365

The epitope of monoclonal antibodies blocking erythrocyte invasion by Plasmodium falciparum map to the dimerization and receptor glycan binding sites of EBA-175.  

PubMed

The malaria parasite, Plasmodium falciparum, and related parasites use a variety of proteins with Duffy-Binding Like (DBL) domains to bind glycoproteins on the surface of host cells. Among these proteins, the 175 kDa erythrocyte binding antigen, EBA-175, specifically binds to glycophorin A on the surface of human erythrocytes during the process of merozoite invasion. The domain responsible for glycophorin A binding was identified as region II (RII) which contains two DBL domains, F1 and F2. The crystal structure of this region revealed a dimer that is presumed to represent the glycophorin A binding conformation as sialic acid binding sites and large cavities are observed at the dimer interface. The dimer interface is largely composed of two loops from within each monomer, identified as the F1 and F2 ?-fingers that contact depressions in the opposing monomers in a similar manner. Previous studies have identified a panel of five monoclonal antibodies (mAbs) termed R215 to R218 and R256 that bind to RII and inhibit invasion of erythrocytes to varying extents. In this study, we predict the F2 ?-finger region as the conformational epitope for mAbs, R215, R217, and R256, and confirm binding for the most effective blocking mAb R217 and R215 to a synthetic peptide mimic of the F2 ?-finger. Localization of the epitope to the dimerization and glycan binding sites of EBA-175 RII and site-directed mutagenesis within the predicted epitope are consistent with R215 and R217 blocking erythrocyte invasion by Plasmodium falciparum by preventing formation of the EBA-175- glycophorin A complex. PMID:23457550

Ambroggio, Xavier; Jiang, Lubin; Aebig, Joan; Obiakor, Harold; Lukszo, Jan; Narum, David L

2013-01-01

366

Dielectric properties of La 1.75Ba 0.25NiO 4 ceramics prepared by spark plasma sintering  

Microsoft Academic Search

The microstructure and dielectric properties of La1.75Ba0.25NiO4 ceramics prepared by spark plasma sintering (SPS) process were investigated. The interstitial oxygen could be removed by the SPS process, and this would induce the significant decrease of electrical conductivity of the sample. The grain growth could be suppressed while the pore removal could be enhanced by the SPS process. The dielectric constant

C. L. Song; Y. J. Wu; X. Q. Liu; X. M. Chen

2010-01-01

367

Fatigue crack growth of Ti62222 titanium alloy under constant amplitude and miniTWIST flight spectra at 25°C and 175°C  

Microsoft Academic Search

Fatigue crack growth behavior was investigated for Ti-62222 titanium alloy under constant amplitude (R = 0.1 and 0.5) and miniTWIST flight spectra at 25 and 175°C. Crack closure was observed at threshold and near threshold for both temperatures with R = 0.1 but not for R = 0.5. Based upon applied or effective ?K, fatigue crack growth behavior for a

R. R. Stephens; R. I. Stephens; A. L. Veit; T. P. Albertson

1997-01-01

368

?-heregulin is the product of a chromosomal translocation fusing the DOC4 and HGL\\/NRG1 genes in the MDA-MB-175 breast cancer cell line  

Microsoft Academic Search

?-heregulin is a recently described novel isoform of the heregulin\\/neuregulin class of EGF-like ligands that bind to and activate receptors of the ErbB family. Deregulated signaling through the heregulin-ErbB pathway is thought to be implicated in the development of a subset of human breast cancers. ?-heregulin has been found to be expressed in the culture supernatant of MDA-MB-175, a breast

Xiao-Zhong Wang; Ethel M Jolicoeur; Nathalie Conte; Max Chaffanet; Yuhong Zhang; Marie-Joëlle Mozziconacci; Helen Feiner; Daniel Birnbaum; Marie-Josèphe Pébusque; David Ron

1999-01-01

369

The Q175 Mouse Model of Huntington's Disease Shows Gene Dosage- and Age-Related Decline in Circadian Rhythms of Activity and Sleep  

PubMed Central

Sleep and circadian disruptions are commonly reported by patients with neurodegenerative diseases, suggesting these may be an endophenotype of the disorders. Several mouse models of Huntington’s disease (HD) that recapitulate the disease progression and motor dysfunction of HD also exhibit sleep and circadian rhythm disruption. Of these, the strongest effects are observed in the transgenic models with multiple copies of mutant huntingtin gene. For developing treatments of the human disease, knock-in (KI) models offer advantages of genetic precision of the insertion and control of mutation copy number. Therefore, we assayed locomotor activity and immobility-defined sleep in a new model of HD with an expansion of the KI repeats (Q175). We found evidence for gene dose- and age-dependent circadian disruption in the behavior of the Q175 line. We did not see evidence for loss of cells or disruption of the molecular oscillator in the master pacemaker, the suprachiasmatic nucleus (SCN). The combination of the precise genetic targeting in the Q175 model and the observed sleep and circadian disruptions make it tractable to study the interaction of the underlying pathology of HD and the mechanisms by which the disruptions occur.

Loh, Dawn H.; Kudo, Takashi; Truong, Danny; Wu, Yingfei; Colwell, Christopher S.

2013-01-01

370

Involvement of MAP3K8 and miR-17-5p in Poor Virologic Response to Interferon-Based Combination Therapy for Chronic Hepatitis C  

PubMed Central

Despite advances in chronic hepatitis C treatment, a proportion of patients respond poorly to treatment. This study aimed to explore hepatic mRNA and microRNA signatures involved in hepatitis C treatment resistance. Global hepatic mRNA and microRNA expression profiles were compared using microarray data between treatment responses. Quantitative real-time polymerase chain reaction validated the gene signatures from 130 patients who were infected with hepatitis C virus genotype 1b and treated with pegylated interferon-alpha and ribavirin combination therapy. The correlation between mRNA and microRNA was evaluated using in silico analysis and in vitro siRNA and microRNA inhibition/overexpression experiments. Multivariate regression analysis identified that the independent variables IL28B SNP rs8099917, hsa-miR-122-5p, hsa-miR-17-5p, and MAP3K8 were significantly associated with a poor virologic response. MAP3K8 and miR-17-5p expression were inversely correlated with treatment response. Furthermore, miR-17-5p repressed HCV production by targeting MAP3K8. Collectively, the data suggest that several molecules and the inverse correlation between mRNA and microRNA contributed to a host genetic refractory hepatitis C treatment response.

Tsubota, Akihito; Mogushi, Kaoru; Aizaki, Hideki; Miyaguchi, Ken; Nagatsuma, Keisuke; Matsudaira, Hiroshi; Kushida, Tatsuya; Furihata, Tomomi; Tanaka, Hiroshi; Matsuura, Tomokazu

2014-01-01

371

Involvement of MAP3K8 and miR-17-5p in poor virologic response to interferon-based combination therapy for chronic hepatitis C.  

PubMed

Despite advances in chronic hepatitis C treatment, a proportion of patients respond poorly to treatment. This study aimed to explore hepatic mRNA and microRNA signatures involved in hepatitis C treatment resistance. Global hepatic mRNA and microRNA expression profiles were compared using microarray data between treatment responses. Quantitative real-time polymerase chain reaction validated the gene signatures from 130 patients who were infected with hepatitis C virus genotype 1b and treated with pegylated interferon-alpha and ribavirin combination therapy. The correlation between mRNA and microRNA was evaluated using in silico analysis and in vitro siRNA and microRNA inhibition/overexpression experiments. Multivariate regression analysis identified that the independent variables IL28B SNP rs8099917, hsa-miR-122-5p, hsa-miR-17-5p, and MAP3K8 were significantly associated with a poor virologic response. MAP3K8 and miR-17-5p expression were inversely correlated with treatment response. Furthermore, miR-17-5p repressed HCV production by targeting MAP3K8. Collectively, the data suggest that several molecules and the inverse correlation between mRNA and microRNA contributed to a host genetic refractory hepatitis C treatment response. PMID:24819603

Tsubota, Akihito; Mogushi, Kaoru; Aizaki, Hideki; Miyaguchi, Ken; Nagatsuma, Keisuke; Matsudaira, Hiroshi; Kushida, Tatsuya; Furihata, Tomomi; Tanaka, Hiroshi; Matsuura, Tomokazu

2014-01-01

372

A Novel Missense Mutation in the Thyroid Peroxidase Gene, R175Q, Resulting in Insufficient Cell Surface Enzyme in Two Siblings  

PubMed Central

Thyroid peroxidase (TPO) abnormality is one of the causes of congenital hypothyroidism. Two missense mutations were found as a compound heterozygous mutation in two siblings with congenital goitrous hypothyroidism. One of these mutations, G614A (R175Q), was a novel mutation. Characterization of the novel mutation and a cotransfection experiment with two mutated TPO mRNAs were carried out. G614A-mRNA introduced into CHO-K1 cells expressed TPO protein with the same molecular weight as that of wild-type mRNA. The R175Q-TPO was thought to possess enzyme activity. In terms of localization, a very small amount of mutated TPO was expressed on the plasma membrane of CHO-K1 cells. This plasma membrane expression of R175Q-TPO was insufficient to perform thyroid hormone synthesis, but was markedly different from R665W-TPO. When G614A- and C2083T-mRNAs were cotransfected, cell surface TPO-positive cells were only 13.1% in contrast to 54.4% for wild-type mRNA. The low positivity and intensity of cell surface TPO suggested that in the patients’ thyroids thyroid hormone synthesis was hardly performed. The congenital hypothyroidism of the patients was thought to be a result of the mutations of the TPO gene (G614A/C2083T).

Kotani, Tomio; Umeki, Kazumi; Kawano, Jun-ichi; Suganuma, Tatsuo; Yamamoto, Ikuo; Aratake, Yatsuki; Ichiba, Yozo; Furujo, Mahoko

2004-01-01

373

Reversible switching of coordination mode of ansa bis(amidinate) ligand in ytterbium complexes driven by oxidation state of the metal atom.  

PubMed

Reaction of bisamidine C6H4-1,2-{NC(t-Bu)NH(2,6-Me2C6H3)}2 (1) and [(Me3Si)2N]2Yb(THF)2 (THF = tetrahydrofuran) (toluene; room temperature) in a 1:1 molar ratio afforded a bis(amidinate) Yb(II) complex [C6H4-1,2-{NC(t-Bu)N(2,6-Me2C6H3)}2]Yb(THF) (2) in 65% yield. Complex 2 features unusual ?(1)amide, ?(6)-arene coordination of both amidinate fragments to the ytterbium ion, resulting in the formation of a bent bis(arene) structure. Oxidation of 2 by Ph3SnCl (1:1 molar ratio) or (PhCH2S)2 (1:0.5) leads to the Yb(III) species [C6H4-1,2-{NC(t-Bu)N(2,6-Me2C6H3)}2]YbCl(1,2-dimethoxyethane) (3) and {[C6H4-1,2-{NC(t-Bu)N(2,6-Me2C6H3)}2]Yb(?-SCH2Ph)}2 (4), performing "classic" ?(2)N,N'-chelating coordination mode of ansa bis(amidinate) ligand. By the reduction of 3 with equimolar amount of sodium naphthalide [C10H8(•-)][Na(+)] in THF, complex 2 can be recovered and restored to a bent bis(arene) structure. Complex 3 was also synthesized by the salt metathesis reaction of equimolar amounts of YbCl3 and the dilithium derivative of 1 in THF. PMID:24446704

Tolpygin, Aleksei O; Cherkasov, Anton V; Fukin, Georgii K; Trifonov, Alexander A

2014-02-01

374

Repression of miR-17-5p with elevated expression of E2F-1 and c-MYC in non-metastatic hepatocellular carcinoma and enhancement of cell growth upon reversing this expression pattern  

SciTech Connect

Highlights: •The oncogenic miR-17-5p is downregulated in non-metastatic hepatocellular carcinoma patients. •E2F-1 and c-MYC transcripts are upregulated in non-metastatic HCC patients. •miR-17-5p forced overexpression inhibited E2F-1 and c-MYC expression in HuH-7 cells. •miR-17-5p mimicking increased HuH-7 cell growth, proliferation, migration and colony formation. •miR-17-5p is responsible for HCC progression among the c-MYC/E2F-1/miR-17-5p triad members. -- Abstract: E2F-1, c-MYC, and miR-17-5p is a triad of two regulatory loops: a negative and a positive loop, where c-MYC induces the expression of E2F-1 that induces the expression of miR-17-5p which in turn reverses the expression of E2F-1 to close the loop. In this study, we investigated this triad for the first time in hepatocellular carcinoma (HCC), where miR-17-5p showed a significant down-regulation in 23 non-metastatic HCC biopsies compared to 10 healthy tissues; however, E2F-1 and c-MYC transcripts were markedly elevated. Forced over-expression of miR-17-5p in HuH-7 cells resulted in enhanced cell proliferation, growth, migration and clonogenicity with concomitant inhibition of E2F-1 and c-MYC transcripts expressions, while antagomirs of miR-17-5p reversed these events. In conclusion, this study revealed a unique pattern of expression for miR-17-5p in non-metastatic HCC patients in contrast to metastatic HCC patients. In addition we show that miR-17-5p is the key player among the triad that tumor growth and spread.

El Tayebi, H.M.; Omar, K.; Hegy, S.; El Maghrabi, M.; El Brolosy, M. [The Molecular Pathology Research Group, Department of Pharmacology and Toxicology, Faculty of Pharmacy and Biotechnology, German University in Cairo, Cairo (Egypt)] [The Molecular Pathology Research Group, Department of Pharmacology and Toxicology, Faculty of Pharmacy and Biotechnology, German University in Cairo, Cairo (Egypt); Hosny, K.A. [Department of General Surgery, Faculty of Medicine, Cairo University, Cairo (Egypt)] [Department of General Surgery, Faculty of Medicine, Cairo University, Cairo (Egypt); Esmat, G. [Department of Endemic Medicine and Hepatology, Cairo University, Cairo (Egypt)] [Department of Endemic Medicine and Hepatology, Cairo University, Cairo (Egypt); Abdelaziz, A.I., E-mail: ahmed.abdel-aziz@guc.edu.eg [The Molecular Pathology Research Group, Department of Pharmacology and Toxicology, Faculty of Pharmacy and Biotechnology, German University in Cairo, Cairo (Egypt)

2013-05-10

375

Age-Dependent IgG Subclass Responses to Plasmodium falciparum EBA-175 Are Differentially Associated with Incidence of Malaria in Mozambican Children  

PubMed Central

Plasmodium falciparum blood-stage antigens such as merozoite surface protein 1 (MSP-1), apical membrane antigen 1 (AMA-1), and the 175-kDa erythrocyte binding antigen (EBA-175) are considered important targets of naturally acquired immunity to malaria. However, it is not clear whether antibodies to these antigens are effectors in protection against clinical disease or mere markers of exposure. In the context of a randomized, placebo-controlled trial of intermittent preventive treatment in infants conducted between 2002 and 2004, antibody responses to Plasmodium falciparum blood-stage antigens in a cohort of 302 Mozambican children were evaluated by immunofluorescence antibody test and enzyme-linked immunosorbent assay at 5, 9, 12, and 24 months of age. We found that IgG subclass responses to EBA-175 were differentially associated with the incidence of malaria in the follow-up period. A double amount of cytophilic IgG1 or IgG3 was associated with a significant decrease in the incidence of malaria (incidence rate ratio [IRR] = 0.49, 95% confidence interval [CI] = 0.25 to 0.97, and P = 0.026 and IRR = 0.44, CI = 0.19 to 0.98, and P = 0.037, respectively), while a double amount of noncytophilic IgG4 was significantly correlated with an increased incidence of malaria (IRR = 3.07, CI = 1.08 to 8.78, P = 0.020). No significant associations between antibodies to the 19-kDa fragment of MSP-1 (MSP-119) or AMA-1 and incidence of malaria were found. Age, previous episodes of malaria, present infection, and neighborhood of residence were the main factors influencing levels of antibodies to all merozoite antigens. Deeper understanding of the acquisition of antibodies against vaccine target antigens in early infancy is crucial for the rational development and deployment of malaria control tools in this vulnerable population.

Quelhas, Diana; Quinto, Llorenc; Puyol, Laura; Serra-Casas, Elisa; Mayor, Alfredo; Nhampossa, Tacilta; Macete, Eusebio; Aide, Pedro; Mandomando, Inacio; Sanz, Sergi; Puniya, Sanjeev K.; Singh, Bijender; Gupta, Puneet; Bhattacharya, Arindam; Chauhan, Virander S.; Aponte, John J.; Chitnis, Chetan E.; Alonso, Pedro L.; Menendez, Clara

2012-01-01

376

Pion production by protons on a thin beryllium target at 6.4, 12.3, and 17.5 GeV/c incident proton momenta  

SciTech Connect

An analysis of inclusive pion production in proton-beryllium collisions at 6.4, 12.3, and 17.5 GeV/c proton beam momentum has been performed. The data were taken by Experiment 910 at the Alternating Gradient Synchrotron at the Brookhaven National Laboratory. The differential {pi}{sup +} and {pi}{sup -} production cross sections (d{sup 2}{sigma}/dpd{omega}) were measured up to 400 mrad in {theta}{sub {pi}} and up to 6 GeV/c in p{sub {pi}}. The measured cross section was fit with a Sanford-Wang parametrization.

Chemakin, I.; Cole, B. A.; Monroe, J.; Sorel, M.; Winter, D. L.; Yang, X.; Zajc, W. A.; Zhang, Y. [Columbia University, New York, New York 10027 (United States); Cianciolo, V. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Fernow, R. C.; Gushue, S.; Kirk, H. G.; Remsberg, L. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Frawley, A. D.; Maeda, N. [Florida State University, Tallahassee, Florida 32306 (United States); Gilkes, M.; McGrath, R. L. [State University of New York, Stony Brook, New York 11794 (United States); Hartouni, E. P.; Namboodiri, M. N.; Soltz, R. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] (and others)

2008-01-15

377

Design of Apparatus for Ni/Mg2Si and Ni/MnSi1.75 Contact Resistance Determination for Thermoelectric Legs  

NASA Astrophysics Data System (ADS)

In recent decades, thermoelectricity has been widely studied as a potential new source of renewable energy. One of the major challenges to improve the efficiency of thermoelectric (TE) devices is to minimize the contact resistance between the active material and the electrodes, since this represents the major loss of charge in a TE module. This article describes the fabrication of an apparatus for TE leg characterization built with commercial and custom-made parts based on the analog one-dimensional transmission-line method. This device permits contact resistance measurements of bulk TE legs. p- and n-type TE materials, Mg2Si0.98Bi0.02 and MnSi1.75Ge0.02, respectively, were metallized with nickel foils and used as test materials for contact resistance characterization. Contact resistance values of 0.5 m? mm2 for Ni/Mg2Si0.98Bi0.02 junctions and 4 m? mm2 for Ni/MnSi1.75Ge0.02 junctions have been measured. Contact resistance measurements are discussed depending on materials processing and the experimental measurement conditions.

Thimont, Yohann; Lognoné, Quentin; Goupil, Christophe; Gascoin, Franck; Guilmeau, Emmanuel

2014-01-01

378

Characterization of the PILATUS photon-counting pixel detector for X-ray energies from 1.75 keV to 60 keV  

NASA Astrophysics Data System (ADS)

The PILATUS detector module was characterized in the PTB laboratory at BESSY II comparing modules with 320 ?m thick and newly developed 450 ?m and 1000 ?m thick silicon sensors. Measurements were carried out over a wide energy range, in-vacuum from 1.75 keV to 8.8 keV and in air from 8 keV to 60 keV. The quantum efficiency (QE) was measured as a function of energy and the spatial resolution was measured at several photon energies both in terms of the modulation transfer function (MTF) from edge profile measurements and by directly measuring the point spread function (PSF) of a single pixel in a raster scan with a pinhole beam. Independent of the sensor thickness, the measured MTF and PSF come close to those for an ideal pixel detector with the pixel size of the PILATUS detector (172 × 172 ?m2). The measured QE follows the values predicted by calculation. Thicker sensors significantly enhance the QE of the PILATUS detectors for energies above 10 keV without impairing the spatial resolution and noise-free detection. In-vacuum operation of the PILATUS detector is possible at energies as low as 1.75 keV.

Donath, T.; Brandstetter, S.; Cibik, L.; Commichau, S.; Hofer, P.; Krumrey, M.; Lüthi, B.; Marggraf, S.; Müller, P.; Schneebeli, M.; Schulze-Briese, C.; Wernecke, J.

2013-03-01

379

Ni59.0Mn23.5In17.5 Heusler alloy as the core of glass-coated microwires: Magnetic properties and magnetocaloric effect  

NASA Astrophysics Data System (ADS)

Heusler Ni59.0Mn23.5In17.5 alloy was prepared as the metallic core of a glass-coated microwire with a total diameter of 41.8 ?m. X-ray diffractograms performed at room temperature and 100 K show a highly ordered L21 cubic structure characteristic of the austenitic phase in Heusler alloys. Thermomagnetic curves measured in the temperature range from 50 K up to 400 K show ferromagnetic coupling in the austenite with the Curie temperature around 246 K. Hysteresis loops measured at different temperatures indicate a soft ferromagnetic behaviour, confirming the microwire axis as the magnetization easy direction. The magnetic entropy variation reaches a maximum value of 1.75 J/kgK at the ferro-to-paramagnetic phase transition for a magnetic field change of 30 kOe. After short annealing, the Curie temperature is almost unchanged while the maximum entropy change increases up to 2.01 J/kgK. Refrigerant capacity and its dependence on both working temperature range and applied field value are evaluated for all microwire samples, reaching 120 J/kg for a 30 kOe magnetic field variation. We analyze the possibility of employing microwire shape Heusler alloys as low field magnetocaloric micro-devices and solid-state actuators.

Vega, V.; González, L.; García, J.; Rosa, W. O.; Serantes, D.; Prida, V. M.; Badini, G.; Varga, R.; Suñol, J. J.; Hernando, B.

2012-08-01

380

Electronic spectral parameters and IR nonlinear optical features of novel Ag0.5Pb1.75GeS4 crystal  

NASA Astrophysics Data System (ADS)

In this paper, we report on novel Ag0.5Pb1.75GeS4 single crystals grown by the Bridgman-Stockbarger method. For these crystals we have performed X-ray photoelectron spectroscopy (XPS) studies of the valence-band and core-level electron states. Second harmonic generation efficiency of Ag0.5Pb1.75GeS4 powder samples by using CO2 laser light depending on the power density up to 1100 MW/cm2 has been obtained within the temperature range 77-520 K. The obtained dependences indicate relatively strong enhancement of photoinduced SHG output efficiencies as temperature increases. Both the spectra taken at ambient and 520 K temperatures have shown similar behavior—rapid growth to saturated values of SHG efficiency with an increase of fundamental beam power density up to 400 MW/cm2, then slowly decreasing with power density reaching a value of 800 MW/cm2 and finally these features show a second small maximum at a fundamental beam power density equal to 900 MW/cm2. Beyond this power density both SHG values start to decrease.

Kogut, Y.; Khyzhun, O. Y.; Parasyuk, O. V.; Reshak, A. H.; Lakshminarayana, G.; Kityk, I. V.; Piasecki, M.

2012-09-01

381

Etudes optiques de nouveaux materiaux laser: Des orthosilicates dopes a l'ytterbium: Le yttrium (lutetium,scandium) pentoxide de silicium  

NASA Astrophysics Data System (ADS)

La decouverte et l'elaboration de nouveaux materiaux laser solides suscitent beaucoup d'interet parmi la communaute scientifique. En particulier les lasers dans la gamme de frequence du micron debouchent sur beaucoup d'applications, en telecommunication, en medecine, dans le domaine militaire, pour la, decoupe des metaux (lasers de puissance), en optique non lineaire (doublage de frequence, bistabilite optique). Le plus couramment utilise actuellement est le Nd:YAG dans cette famille de laser, mais des remplacants plus performants sont toujours recherches. Les lasers a base d'Yb3+ possedent beaucoup d'avantages compares aux lasers Nd3+ du fait de leur structure electronique simple et de leur deterioration moins rapide. Parmi les matrices cristallines pouvant accueillir l'ytterbium, les orthosilicates Yb:Y 2SiO5, Yb:Lu2SiO5 et Yb:Sc2SiO 5 se positionnent tres bien, du fait de leur bonne conductivite thermique et du fort eclatement de leur champ cristallin necessaire a l'elaboration de lasers quasi-3 niveaux. De plus l'etude fine et systematique des proprietes microscopiques de nouveaux materiaux s'avere toujours tres interessante du point de vue de la recherche fondamentale, c'est ainsi que de nouveaux modeles sont concus (par exemple pour le champ cristallin) ou que de nouvelles proprietes inhabituelles sont decouvertes, menant a de nouvelles applications. Ainsi d'autres materiaux dopes a l'ytterbium sont connus pour leurs proprietes de couplage electron-phonon, de couplage magnetique, d'emission cooperative ou encore de bistabilite optique, mais ces proprietes n'ont encore jamais ete mises en evidence dans Yb:Y 2SiO5, Yb:Lu2SiO5 et Yb:Sc2SiO 5. Ainsi, cette these a pour but l'etude des proprietes optiques et des interactions microscopiques dans Yb:Y2SiO 5, Yb:Lu2SiO5 et Yb:Sc2SiO5. Nous utilisons principalement les techniques d'absorption IR et de spectroscopie Raman pour determiner les excitations du champ cristallin et les modes de vibration dans le materiau. Des mesures optiques sous champ magnetique ont egalement ete effectuees dans le but de caracteriser le comportement de ces excitations lorsqu'elles sont soumises a l'effet Zeeman. La resonance paramagnetique electronique a permis de completer cette etude de l'eclatement Zeeman suivant toutes les orientations du cristal. Enfin la fluorescence par excitation selective et la fluorescence induite par Raman FT, completent la description des niveaux d'energie et revelent l'existence d'emission cooperative de deux ions Yb3+ et de transferts d'energie. Les resultats de cette these apportent une contribution originale dans le domaine des nouveaux materiaux lasers par l'etude et la comprehension des interactions fines et des proprietes microscopiques d'un materiau en particulier. Ils debouchent a la fois sur des applications possibles dans le domaine de l'optique et des lasers, et sur la comprehension d'aspects fondamentaux. Cette these a prouve l'interet de ces matrices pour leur utilisation comme lasers solides: un fort eclatement du champ cristallin favorable a l'elaboration de laser quasi-3 niveaux, et de larges bandes d'absorption (dues a un fort couplage electron-phonon et a des raies satellites causees par une interaction d'echange entre deux ions Yb3+) qui permettent la generation d'impulsions laser ultra-courtes, l'accordabilite du laser, etc. De plus la miniaturisation des lasers est possible pour l'optique integree grace a des couches minces synthetisees par epitaxie en phase liquide dont nous avons demontre la tres bonne qualite structurale et l'ajustement possible de certains parametres. Nous avons reconstruit le tenseur g du niveau fondamental (qui donne des informations precieuses sur les fonctions d'onde), ceci dans le but d'aider les theoriciens a concevoir un modele de champ cristallin valide. Plusieurs mecanismes de transferts d'energie ont ete mis en evidence: un mecanisme de relaxation d'un site vers l'autre, un mecanisme d'emission cooperative, et un mecanisme d'excitation de l'Yb3+ par le Tm3+ (impurete presente dans le materiau). Ces transferts sont

Denoyer, Aurelie

382

Activation cross-sections of longer lived products of deuteron induced nuclear reactions on ytterbium up to 40 MeV  

NASA Astrophysics Data System (ADS)

In the frame of a systematic study of the activation cross-sections of the deuteron induced nuclear reactions, excitation functions of the natYb(d,xn)177,173,172mg,171mg,170,169Lu, natYb(d,x)175,169Yb and natYb(d,x)173,172,168,167,165Tm reactions are studied up to 40 MeV, a few of them for the first time. Cross-sections were measured with the activation method using a stacked foil irradiation technique and high resolution ?-ray spectrometry. The experimental data are analyzed and compared to the results of the theoretical model codes ALICE-IPPE, EMPIRE-II and TALYS. From the measured cross-section data integral production yields were calculated. Applications of the new cross-sections are discussed.

Tárkányi, F.; Ditrói, F.; Takács, S.; Hermanne, A.; Yamazaki, H.; Baba, M.; Mohammadi, A.; Ignatyuk, A. V.

2013-06-01

383

Demonstration of optical parametric gain generation in the 1 ?m regime based on a photonic crystal fiber pumped by a picosecond mode-locked ytterbium-doped fiber laser  

NASA Astrophysics Data System (ADS)

We report the experimental demonstration of the optical parametric gain generation in the 1 ?m regime based on a photonic crystal fiber (PCF) with a zero group velocity dispersion (GVD) wavelength of 1062 nm pumped by a homemade tunable picosecond mode-locked ytterbium-doped fiber laser. A broad parametric gain band is obtained by pumping the PCF in the anomalous GVD regime with a relatively low power. Two separated narrow parametric gain bands are observed by pumping the PCF in the normal GVD regime. The peak of the parametric gain profile can be tuned from 927 to 1038 nm and from 1099 to 1228 nm. This widely tunable parametric gain band can be used for a broad band optical parametric amplifier, large span wavelength conversion or a tunable optical parametric oscillator.

Zhang, Lei; Yang, Si-Gang; Wang, Xiao-Jian; Gou, Dou-Dou; Chen, Hong-Wei; Chen, Ming-Hua; Xie, Shi-Zhong

2014-01-01

384

Framework composed of interconnected quadruple-octahedra infinite chains: Synthesis and structure of calcium ytterbium sulfide, CaYb 2S 4, with the Yb 3S 4-type structure  

NASA Astrophysics Data System (ADS)

Single crystals of the ternary calcium ytterbium compound, CaYb 2S 4, have been synthesized using an eutectic, halide flux and have been structurally characterized by the X-ray single-crystal diffraction method. The compound crystallizes in an orthorhombic unit cell, Pnma (No. 62), with cell dimensions of a = 12.807 (3) Å, b = 3.836 (2) Å, c = 12.964 (3) Å, V = 636.9 (7) Å 3, and Z = 4. The least-squares refinement of 658 observed reflections (with F20 > 3 ? ( F20)) gives a final structure solution of R = 0.026, Rw = 0.030, and GOF = 1.06 for 45 variables. This compound has adopted a Yb 3S 4-type structure in which the 7-coordinated divalent Yb 2+ sites are occupied by Ca 2+ cations. The refined occupancy factor on the calcium site suggests some nonstoichiometry, which is attributed to the solid solution of a ytterbium-rich phase. The crystal formula found is Ca 1- xYb 2+ xS 4 ( x = 0.04). The CaYb 2S 4 structure is a three-dimensional lattice which consists of interconnected quadruple-octahedra infinite chains. Each quadruple chain is built up from four edge-sharing octahedra that are composed of two pairs of asymmetric Yb(1)S 6 and Yb(2)S 6 groups. Structure comparison with another ternary rare-earth sulfide bearing a larger alkaline earth metal cation, BaSm 2S 4 (CaFe 2O 4-type), gives rise to some important insight for structure formation of rare-earth chalcogenide compounds.

Carpenter, James D.; Hwu, Shiou-Jyh

1992-04-01

385

Effect of casing treatment of overall performance of axial-flow transonic fan stage with pressure ratio of 1.75 and tip solidity of 1.5  

NASA Technical Reports Server (NTRS)

The effect of a number of casing treatments on the overall performance of a 1.75-pressure-ratio, 423-m/sec-tip-speed fan stage was evaluated. The skewed slot configuration with short-open slots over the midportion of the rotor had a stall margin of 23.5 percent, while the solid casing had a stall margin of 15.0 percent. The skewed slot configuration with long open slots extending ahead of and over portion of rotor displaced the stall line to the lowest flow at all speeds tested. At design speed, the peak efficiency for the long, forward open slots was 1 point less than that for the short midopen slots and 3 points less than that for the solid casing.

Osborn, W. M.; Moore, R. D.

1977-01-01

386

Lattice, electrical, and magnetic effects in lanthanum manganites La1- x Sr x MnO3 ( x = 0.125, 0.150, 0.175)  

NASA Astrophysics Data System (ADS)

The temperature dependences of the velocities of transverse and longitudinal hypersound in lanthanum strontium manganites of the composition La1- x Sr x MnO3 ( x = 0.125, 0.150, 0.175) have been measured at frequencies of 0.5-0.7 GHz. The structural phase transitions have been revealed, and their positions have been confirmed by data on the electrical resistance and magnetic measurements performed using the same samples. The results obtained have been analyzed in the framework of the model of competing Jahn-Teller distortions and magnetic ordering. The anomalies observed in the behavior of the velocities of longitudinal hypersound have been attributed to the local Jahn-Teller distortions, and their suppression due to the magnetic ordering has been considered a possible factor responsible for the colossal magnetoresistance.

Bulatov, A. R.; Bogdanova, Kh. G.; Golenishchev-Kutuzov, V. A.; Elokhina, L. V.; Ne?fel'D, É. A.; Korolev, A. V.

2010-11-01

387

Semi-inclusive {lambda} and K{sub S} production in p-Au collisions at 17.5 GeV/c  

SciTech Connect

The first detailed measurements of the centrality dependence of strangeness production in p-A collisions are presented. {lambda} and K{sub S} dn/dy distributions from 17.5 GeV/c p-Au collisions are shown as a function of ''grey'' track multiplicity and the estimated number of collisions, {nu}, made by the proton. The {nu} dependence of the {Lambda} yield deviates from a scaling of p-p data by the number of participants, increasing faster than this scaling for {nu} {le} 5 and saturating for larger {nu}. A slower growth in K{sub S} multiplicity with {nu} is observed, consistent with a weaker {nu} dependence of KK-bar production than YK production.

Chemakin, I.; Cianciolo, V.; Cole, B.; Fernow, R.; Frawley, A.; Gilkes, M.; Gushue, S.; Hartouni, E.; Hiejima, H.; Justice, M.; Kang, J.; Kirk, H.; Maeda, N.; McGrath, R.; Mioduszewski, S.; Morrison, D.; Moulson, M.; Namboodiri, M.; Rai, G.; Read, K.; Remsberg, L.; Rosati, M.; Shin, Y.; Soltz, R.; Sorenson, S.; Thomas, J.; Torun, Y.; Winter, D.; Yang, X.; Zajc, W.; Zhang, Y.

2001-09-14

388

Optical properties of the cation-deficient platinum chain salt K1.75Pt(CN)4.1.5H2O  

NASA Astrophysics Data System (ADS)

The room-temperature polarized reflectance of a potassium-deficient platinum chain salt K1.75Pt(CN)4.1.5H2O [K(def)CP] has been measured in the infrared and visible. The reflectance is strongly anisotropic, with a plasma edge in the red and high reflectance in the infrared for light polarized parallel to the Pt chain axis and almost frequency-independent reflectance for the transverse polarization. Analysis of the plasma edge indicates a nearly-free-electron mass for the conduction electrons. The data show the existence of an energy gap at room temperature and suggest a Peierls transition above room temperature. The parallel polarized reflectance has structure in the infrared which is the first direct evidence for strong coupling of the conduction electrons to the C ? N stretching vibration of the tetracyanoplatinate unit in quasi-one-dimensional platinum chain conductors.

Greene, L. H.; Tanner, D. B.; Epstein, A. J.; Miller, Joel S.

1982-01-01

389

X-ray structure at 1.75 resolution of a norovirus 3C protease linked to an active site-directed peptide inhibitor  

SciTech Connect

Noroviruses are recognized universally as the most important cause of human epidemic non-bacterial gastroenteritis. Viral replication requires a 3C cysteine protease that cleaves a 200kDa viral polyprotein into its constituent functional proteins. Here we describe the X-ray structure of the Southampton norovirus 3C protease (SV3CP) bound to an active site-directed peptide inhibitor (MAPI) which has been refined at 1.75 resolution, following initial MAD phasing with a selenomethionine derivative. The inhibitor, acetyl-Glu-Phe-Gln-Leu-Gln-X, based on a 3C protease cleavage recognition sequences in the 200kDa polyprotein substrate, reacts covalently through its propenylethylester group (X) with the active site nucleophile, Cys 139. The 3C protease-inhibitor structure permits, for the first time, the identification of substrate recognition and binding groups and provides important new information for the development of antiviral prophylactics.

Cooper, Jon [University of Southampton, England; Coates, Leighton [ORNL; Hussey, Robert [University of Southampton, England

2010-01-01

390

Will this marriage work: California unites utilities and solar - for better or worse. [PVC financing test of 175,000 solar water heaters over 3 yrs  

SciTech Connect

The California Public Utility Commission (PUC) is financing the country's largest utility-solar program, one which will test 175,000 solar water heaters in homes over a three-year period. The controversial program was prompted because traditional financing methods and solar tax credits were not meeting the state's goal for solar applications. Customer acceptance was further slowed by a lack of information. The PUC responded by setting up a program to force utility financing to allow residential consumers to conveniently buy a solar hot-water system. Targeted for a range of neighborhoods and income groups, the program offers free delivery and installation and one of four payback plans. Four major utilities will participate in the demonstration. Opponents to the plan predict power shortages unless utilities spend the money for new plant construction, point to the conflict of interest it represents for investor-owned utilities, and object to having the utilities in control of solar energy. (DCK)

Woolson, A.

1980-03-01

391

Partial Re-vegetation of the Dust and Blowing-Sand Source Area: A proposal for use of a 175 K$ SEP Fine  

SciTech Connect

We propose using the 175 K$ SEP money to stabilize approximately 300-340 acres located to the southwest of the 200 West Expansion Area fence. We propose a procedure that relies on drill seeding a mixture of perennial native grasses followed by truck application of a soil fixative such as Soil Master. This effort would compliment FDH/Duratek activities planned for inside the 200 West fence lines. Assuming that both efforts are successful, the result would be between 2,000 and 2,500 meters of stabilized soil surface upwind of the primary receptors at MO-281/272-WA, which would result in a significant reduction in respirable dust at the receptor site.

Becker, James M.; Sackschewsky, Michael R.

2001-08-01

392

Semi-inclusive {Lambda} and K{sub S} Production in p -Au Collisions at 17.5 GeV/c  

SciTech Connect

The first detailed measurements of the centrality dependence of strangeness production in p-A collisions are presented. {Lambda} and K{sub S} dn/dy distributions from 17.5GeV/c p-Au collisions are shown as a function of ''grey'' track multiplicity and the estimated number of collisions, {nu} , made by the proton. The {nu} dependence of the {Lambda} yield deviates from a scaling of p-p data by the number of participants, increasing faster than this scaling for {nu}{<=}5 and saturating for larger {nu} . A slower growth in K{sub S} multiplicity with {nu} is observed, consistent with a weaker {nu} dependence of K{bar K} production than YK production.

Chemakin, I.; Cianciolo, V.; Cole, B. A.; Fernow, R.; Frawley, A. D.; Gilkes, M.; Gushue, S.; Hartouni, E. P.; Hiejima, H.; Justice, M. (and others) [and others

2000-12-04

393

Identification of an Erythrocyte Binding Peptide from the Erythrocyte Binding Antigen, EBA-175, Which Blocks Parasite Multiplication and Induces Peptide-Blocking Antibodies  

PubMed Central

A biotinylated peptide covering a sequence of 21 amino acids (aa) from the erythrocyte binding antigen (EBA-175) of Plasmodium falciparum bound to human glycophorin A, an erythrocyte receptor for merozoites, as demonstrated by enzyme-linked immunosorbent assay (ELISA) and to erythrocytes as demonstrated by flow cytometry analysis. The peptide, EBA(aa1076–96), also bound to desialylated glycophorin A and glycophorin B when tested by ELISA. The peptide blocked parasite multiplication in vitro. The glycophorin A binding sequence was further delineated to a 12-aa sequence, EBA(aa1085–96), by testing the binding of a range of truncated peptides to immobilized glycophorin A. Our data indicate that EBA(aa1085–96) is part of a ligand on the merozoite for binding to erythrocyte receptors. This binding suggests that the EBA(aa1085–96) peptide is involved in a second binding step, independent of sialic acid. Antibody recognition of this peptide sequence may protect against merozoite invasion, but only a small proportion of sera from adults from different areas of malaria transmission showed antibody reactivities to the EBA(aa1076–96) peptide, indicating that this sequence is only weakly immunogenic during P. falciparum infections in humans. However, Tanzanian children with acute clinical malaria showed high immunoglobulin G reactivity to the EBA(aa1076–96) peptide compared to children with asymptomatic P. falciparum infections. The EBA(aa1076–96) peptide sequence from EBA-175 induced antibody formation in mice after conjugation of the peptide with purified protein derivative. These murine sera inhibited EBA(aa1076–96) peptide binding to glycophorin A.

Jakobsen, P. H.; Heegaard, P. M. H.; Koch, C.; Wasniowska, K.; Lemnge, M. M.; Jensen, J. B.; Sim, B. K. L.

1998-01-01

394

The expression ratio of miR-17-5p and miR-155 correlates with grading in canine splenic lymphoma.  

PubMed

In dogs as in humans, microRNAs (miRNAs) play a key role in normal and neoplastic hematopoiesis regulation. The general miRNA expression framework varies among different stages of development and differentiation of tumors, and miRNAs are widely investigated as new molecular tools for cancer diagnosis and classification. Canine lymphomas are currently classified according with the WHO classification, but a comprehensive grading study of clinical samples is still lacking, and molecular tools for quick grading are not yet available. In the present work, a retrospective study of the expression profile of a panel of miRNAs in canine primary splenic lymphomas was performed. The formalin fixed, paraffin embedded (FFPE) lymphoma samples were accurately classified according with the WHO classification, and were analyzed for miRNA expression using stem-loop TaqMan real time RT-PCR. For each miRNA investigated, relative and absolute quantification were performed after selecting the best housekeeping genes using the NormFinder and geNorm algorithms. The results of this study show a diversity in miRNA expression in low (L) grade lymphomas compared to intermediate-high (I-H) grade lymphomas. The molar ratio between miR-17-5p and miR-155 correlated with WHO grading. These results highlight the potential use of miR-17-5p/miR-155 molar ratio as a new molecular tool for grading of canine splenic lymphomas. The data here reported further support the utility of monitoring miRNA expression in canine hematopoietic malignancies diagnosis and prognosis. PMID:23871213

Albonico, Francesca; Mortarino, Michele; Avallone, Giancarlo; Gioia, Gloria; Comazzi, Stefano; Roccabianca, Paola

2013-09-01

395

Effects of 2.0-g 1.75-g and 1.5-g Hypergravity on Pregnancy Outcome in Rats (Rattus norvegicus)  

NASA Technical Reports Server (NTRS)

In 1995, ten pregnant female rats were launched on the Space Shuttle (STS-70) on Gestational day(G) 11 of their 22-day pregnancy as part of the NASA/NIH.Rodent (R)2 Experiment. Following landing on G20, fetuses were harvested from half of the dams, while the remaining five dams underwent birth. Spaceflight did not interrupt pregnancy, alter litter sizes, or affect body weights or gender ratios of the fetuses or neonates. In the present study we used the NASA/NIH.R2 experimental paradigm to analyze the effects of hypergravity on pregnancy outcome. On G10, time-bred Sprague-Dawley rat dams were assigned to either G20 or Birth conditions, then further assigned to Hypergravity (HG) 2.0-g, HG 1.75-g, HG 1.5-g, Rotational Control (RC, 1.03), or Stationary Control (SC, 1.0-g) treatments. Dams were exposed to continuous centrifugation from G11 through G20, with brief daily stops for animal health checks and maintenance. For both the G20 and Birth dams, comparable litter sizes and litter gender ratios were observed across gravity conditions. However, centrifugation-exposed (HG and RC) fetuses and neonates showed significantly lower body masses (p less than 0.05) relative to SC offspring. HG 2.0-g offspring weighed significantly less than those in all other gravity conditions (p less than 0.05). The observed reductions in offspring body mass at 1.5-g and 1.75-g, can be attributed to the rotational component of centrifugation, rather than to increased gravitational load, whereas 2.0-g hypergravity exposure further exacerbated the gravity centrifugation effect on offspring body mass. Pregnant dams exposed to centrifugation weighed significantly less than SC dams (p less than 0.05), suggesting that centrifugation effects on maternal body mass may contribute to reduced size of the developing offspring. These findings are consistent with previous reports of non-pregnant adult animals suggesting that, whereas spaceflight has virtually no effect on body mass, centrifugation is associated with changes in body weight regulation.

Mills, Nicole A.; Baer, Lisa A.; Ronca, April E.

2001-01-01

396

Incoherent-to-coherent crossover of optical spectra in La0.825Sr0.175MnO3: Temperature-dependent reflectivity spectra measured on cleaved surfaces  

Microsoft Academic Search

Optical reflectivity spectra were measured on cleaved surfaces of La0.825Sr0.175MnO3 single crystals (TC=283 K) over a temperature range 10-295 K. The optical conductivity sigma(omega) shows incoherent-to-coherent crossover with decreasing temperature. The minimum metallic conductivity sigmamin of this compound was determined by the dc resistivity rho(T) measurements of Al-substituted crystals (La0.825Sr0.175)(Mn1-zAlz)O3 and was found to be 2000-3000 Omega-1 cm-1. This indicates

K. Takenaka; Y. Sawaki; S. Sugai

1999-01-01

397

Charge compensation and optimal stoichiometry in superconducting (CaxLa1-x)(Ba1.75-xLa0.25+x)Cu3Oy  

NASA Astrophysics Data System (ADS)

The superconductive and magnetic properties of charge-compensated (CaxLa1-x)(Ba1.75-xLa0.25+x)Cu3Oy (normally denoted as CLBLCO) are considered through quantitative examination of data for electrical resistivity, magnetic susceptibility, transition width, muon-spin rotation, x-ray absorption, and crystal structure. A derivative of LaBa2Cu3Oy, cation doping of this unique tetragonal cuprate is constrained by compensating La substitution for Ba with Ca substitution for La, where for 0 ? x ? 0.5 local maxima in TC occur for y near 7.15. It is shown that optimum superconductivity occurs for 0.4 ? x ? 0.5, that the superconductivity and magnetism observed are nonsymbiotic phenomena, and that charge-compensated doping leaves the carrier density in the cuprate planes nearly invariant with x, implying that only a small fraction of superconducting condensate resides therein. Applying a model of electronic interactions between physically separated charges in adjacent layers, the mean in-plane spacing between interacting charges, ?=7.1206 Å, and the distance between interacting layers, ? = 2.1297 Å, are determined for x = 0.45. The theoretical optimal TC0??-1?-1 of 82.3 K is in excellent agreement with experiment (?80.5 K), bringing the number of compounds for which TC0 is accurately predicted to 37 from six different superconductor families (overall accuracy of ±1.35 K).

Harshman, Dale R.; Fiory, Anthony T.

2012-10-01

398

IDCS J1426.5+3508: SUNYAEV-ZEL'DOVICH MEASUREMENT OF A MASSIVE INFRARED-SELECTED CLUSTER AT z = 1.75  

SciTech Connect

We report 31 GHz CARMA observations of IDCS J1426.5+3508, an infrared-selected galaxy cluster at z = 1.75. A Sunyaev-Zel'dovich (SZ) decrement is detected toward this cluster, indicating a total mass of M{sub 200,m} = (4.3 {+-} 1.1) Multiplication-Sign 10{sup 14} M{sub Sun} in agreement with the approximate X-ray mass of {approx}5 Multiplication-Sign 10{sup 14} M{sub Sun }. IDCS J1426.5+3508 is by far the most distant cluster yet detected via the SZ effect, and the most massive z {>=} 1.4 galaxy cluster found to date. Despite the mere {approx}1% probability of finding it in the 8.82 deg{sup 2} IRAC Distant Cluster Survey, IDCS J1426.5+3508 is not completely unexpected in {Lambda}CDM once the area of large, existing surveys is considered. IDCS J1426.5+3508 is, however, among the rarest, most extreme clusters ever discovered and indeed is an evolutionary precursor to the most massive known clusters at all redshifts. We discuss how imminent, highly sensitive SZ experiments will complement infrared techniques for statistical studies of the formation of the most massive galaxy clusters in the z > 1.5 universe, including potential precursors to IDCS J1426.5+3508.

Brodwin, M. [Department of Physics and Astronomy, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States); Gonzalez, A. H.; Fedeli, C.; Gettings, D.; Mancone, C. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Stanford, S. A.; Zeimann, G. [Department of Physics, University of California, One Shields Avenue, Davis, CA 95616 (United States); Plagge, T.; Carlstrom, J. E.; Leitch, E. M. [Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Marrone, D. P. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Dey, A.; Jannuzi, B. T. [NOAO, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Eisenhardt, P. R.; Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Joy, M. [Department of Space Science, VP62, NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); Snyder, G. F. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA (United States)

2012-07-10

399

Genetic Deletion of Transglutaminase 2 Does Not Rescue the Phenotypic Deficits Observed in R6/2 and zQ175 Mouse Models of Huntington's Disease  

PubMed Central

Huntington's disease (HD) is an autosomal dominant, progressive neurodegenerative disorder caused by expansion of CAG repeats in the huntingtin gene. Tissue transglutaminase 2 (TG2), a multi-functional enzyme, was found to be increased both in HD patients and in mouse models of the disease. Furthermore, beneficial effects have been reported from the genetic ablation of TG2 in R6/2 and R6/1 mouse lines. To further evaluate the validity of this target for the treatment of HD, we examined the effects of TG2 deletion in two genetic mouse models of HD: R6/2 CAG 240 and zQ175 knock in (KI). Contrary to previous reports, under rigorous experimental conditions we found that TG2 ablation had no effect on either motor or cognitive deficits, or on the weight loss. In addition, under optimal husbandry conditions, TG2 ablation did not extend R6/2 lifespan. Moreover, TG2 deletion did not change the huntingtin aggregate load in cortex or striatum and did not decrease the brain atrophy observed in either mouse line. Finally, no amelioration of the dysregulation of striatal and cortical gene markers was detected. We conclude that TG2 is not a valid therapeutic target for the treatment of HD.

Menalled, Liliana B.; Kudwa, Andrea E.; Oakeshott, Steve; Farrar, Andrew; Paterson, Neil; Filippov, Igor; Miller, Sam; Kwan, Mei; Olsen, Michael; Beltran, Jose; Torello, Justin; Fitzpatrick, Jon; Mushlin, Richard; Cox, Kimberly; McConnell, Kristi; Mazzella, Matthew; He, Dansha; Osborne, Georgina F.; Al-Nackkash, Rand; Bates, Gill P.; Tuunanen, Pasi; Lehtimaki, Kimmo; Brunner, Dani; Ghavami, Afshin; Ramboz, Sylvie; Park, Larry; Macdonald, Douglas; Munoz-Sanjuan, Ignacio; Howland, David

2014-01-01

400

17.5% p-Type Silicon Heterojunction Solar Cells with HWCVD a-Si:H as the Emitter and Back Contact  

SciTech Connect

Thin hydrogenated amorphous silicon (a-Si:H) layers deposited by hot-wire chemical vapor deposition (HWCVD) are used as both emitters and back contacts in silicon heterojunction solar cells. Low interface recombination velocity and high open-circuit voltage are achieved by a low substrate temperature (<150 deg C) intrinsic a-Si:H deposition which ensures immediate amorphous silicon deposition. This is followed by deposition of doped a-Si:H at a higher temperature (>200 deg C) which appears to improve dopant activation. With an i/n a-Si:H emitter, we obtain a confirmed efficiency of 17.1% on textured p-type float-zone (FZ) silicon with a screen-printed aluminum back-surface-field (Al-BSF) contact. Employing a-Si:H as both the front emitter and the back contact, we achieve a confirmed efficiency of 17.5%, the highest reported efficiency for a p-type c-Si based heterojunction solar cell.

Wang, T. H.; Page, M. R.; Iwaniczko, E.; Wang, Q.; Xu,Y.; Yan, Y.; Roybal, L.; Levi, D.; Bauer, R.; Branz, H. M.; Yelundur, V.; Rohatgi, A.

2005-11-01

401

Texture and elastic strains in hcp-iron plastically deformed up to 17.5 GPa and 600 K: experiment and model  

NASA Astrophysics Data System (ADS)

Internal elastic strains and textures are measured using monochromatic x-ray diffraction in ?-Fe plastically deformed up to 17.5 GPa and 600 K in the deformation-DIA. We observe the development of a strong 0?0?0?1 compression texture along with a strongly non-linear behavior of 0?0?0?2 lattice strains. We then use an elastoplastic self-consistent polycrystal model to simulate the macroscopic flow curves, internal strain and texture development within the sample. Input parameters are single-crystal elastic moduli, critical resolved shear stresses, and hardening behavior of the slip and twinning mechanisms. The model is found to reproduce the experiment data with basal slip as the easiest and most active deformation mechanism. Other active mechanisms are tensile twinning, prismatic and pyramidal slip. Tensile twinning is most active at lower temperatures (e.g. 400 K) and a higher strain rate. In most cases, the twinning activity occurs early in the deformation and later saturates. It is also responsible for the non-linear behavior of 0?0?0?2 lattice strains. Later in the deformation, the plastic activity of ?-Fe is controlled by basal, prismatic and pyramidal slip.

Merkel, Sébastien; Gruson, Marion; Wang, Yanbin; Nishiyama, Norimasa; Tomé, Carlos N.

2012-03-01

402

IDCS J1426.5+3508: Sunyaev-Zel'dovich Measurement of a Massive Infrared-selected Cluster at z = 1.75  

NASA Astrophysics Data System (ADS)

We report 31 GHz CARMA observations of IDCS J1426.5+3508, an infrared-selected galaxy cluster at z = 1.75. A Sunyaev-Zel'dovich (SZ) decrement is detected toward this cluster, indicating a total mass of M 200, m = (4.3 ± 1.1) × 1014 M ? in agreement with the approximate X-ray mass of ~5 × 1014 M ?. IDCS J1426.5+3508 is by far the most distant cluster yet detected via the SZ effect, and the most massive z >= 1.4 galaxy cluster found to date. Despite the mere ~1% probability of finding it in the 8.82 deg2 IRAC Distant Cluster Survey, IDCS J1426.5+3508 is not completely unexpected in ?CDM once the area of large, existing surveys is considered. IDCS J1426.5+3508 is, however, among the rarest, most extreme clusters ever discovered and indeed is an evolutionary precursor to the most massive known clusters at all redshifts. We discuss how imminent, highly sensitive SZ experiments will complement infrared techniques for statistical studies of the formation of the most massive galaxy clusters in the z > 1.5 universe, including potential precursors to IDCS J1426.5+3508.

Brodwin, M.; Gonzalez, A. H.; Stanford, S. A.; Plagge, T.; Marrone, D. P.; Carlstrom, J. E.; Dey, A.; Eisenhardt, P. R.; Fedeli, C.; Gettings, D.; Jannuzi, B. T.; Joy, M.; Leitch, E. M.; Mancone, C.; Snyder, G. F.; Stern, D.; Zeimann, G.

2012-07-01

403

1.75 h {sup -1} kpc SEPARATION DUAL ACTIVE GALACTIC NUCLEI AT z = 0.36 IN THE COSMOS FIELD  

SciTech Connect

We present strong evidence for dual active galactic nuclei (AGNs) in the z = 0.36 galaxy COSMOS J100043.15+020637.2. COSMOS Hubble Space Telescope (HST) imaging of the galaxy shows a tidal tail, indicating that the galaxy recently underwent a merger, as well as two bright point sources near the galaxy's center. The luminosities of these sources (derived from the HST image) and their emission line flux ratios (derived from Keck/DEIMOS slit spectroscopy) suggest that both are AGNs and not star-forming regions or supernovae. Observations from zCOSMOS, the Sloan Digital Sky Survey, XMM-Newton, Spitzer, and the Very Large Array fortify the evidence for AGN activity. With HST imaging we measure a projected spatial offset between the two AGNs of 1.75 {+-} 0.03 h {sup -1} kpc, and with DEIMOS we measure a 150 {+-} 40 km s{sup -1} line-of-sight velocity offset between the two AGNs. Combined, these observations provide substantial evidence that COSMOS J100043.15+020637.2 is a merger-remnant galaxy with dual AGNs.

Comerford, Julia M.; Davis, Marc [Astronomy Department, 601 Campbell Hall, University of California, Berkeley, CA 94720 (United States); Griffith, Roger L.; Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, MS 169-327, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Gerke, Brian F. [Kavli Institute for Particle Astrophysics and Cosmology, M/S 29, Stanford Linear Accelerator Center, 2575 Sand Hill Rd., Menlo Park, CA 94725 (United States); Cooper, Michael C. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Newman, Jeffrey A. [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States)

2009-09-01

404

IrSr2Sm1.15Ce0.85Cu2.175O10: A reentrant spin-glass material  

NASA Astrophysics Data System (ADS)

A new iridium-containing layered cuprate material, Ir0.825Sr2Sm1.15Ce0.85Cu2.175O10, has been synthesized by conventional ambient-pressure solid-state techniques. The material's structure has been fully characterized by Rietveld refinement of high-resolution synchrotron x-ray diffraction data; tilts and rotations of the IrO6 octahedra are observed as a result of a bond mismatch between in-plane Ir-O and Cu-O bond lengths. DC-susceptibility measurements evidence a complex set of magnetic transitions upon cooling that are characteristic of a reentrant spin-glass ground-state. The glassy character of the lowest-temperature (Tg=10 K) transition is further confirmed by AC-susceptibility measurements, showing a characteristic frequency dependence that can be well fitted by the Vogel-Fulcher law and yields a value of (?Tf)/([Tf?log(?)])=0.015(1), typical of dilute magnetic systems. Electronic transport measurements show the material to be semiconducting at all temperatures, so that the CuO2 planes are underdoped with no evidence of a transition to a superconducting state. Negative magnetoresistance is observed when the material is cooled below 20 K, and the magnitude of this magnetoresistance is seen to increase upon cooling to a value of MR=-9% at 8 K.

Colman, R. H.; Mclaughlin, A. C.

2012-04-01

405

APOA1-75 G to A Substitution Associated with Severe Forms of CAD, Lower Levels of HDL and apoA-I among Northern Indians  

PubMed Central

Apolipoprotein A-I (APOA1 gene, apoA-I protein) is the major protein for plasma high density lipoprotein (HDL). The relationship of APOA1-75G/A polymorphism with lipid profile and coronary artery disease (CAD) is unclear. Out of 370 individuals initially recruited, 164 angiographically proven CAD patients (? 70% stenosis) and 36 individuals with normal coronaries or insignificant CAD (NCAD, ? 50% stenosis) from Delhi and adjoining areas were selected for analysis based on the set criteria. Polymorphism was determined by PCR followed by MspI restriction digestion. Lipid profile was estimated by enzymatic kit and apoA-I levels by immunoturbidimetry. A highly significant increasing trend in ‘A’ allele frequency was observed with the rise in severity of CAD: NCAD (0.097) < SVD (single vessel disease) (0.117) < DVD (double vessel disease) (0.223) < TVD (triple vessel disease) (0.291). In comparison to GG individuals, the OR of ‘A’ allele carriers to develop SVD, DVD, TVD was 1.3, 2.8 and 4.2 respectively (ptrend = 0.007). Analysis of intergenotypic variations in the lipid profile revealed significantly lower levels of HDL and apoA-I among ‘A’ allele carriers as compared to GG (patients). Our study, first of its kind from India, suggests that ‘A’ allele may contribute to severity of CAD and low levels of HDL & apoA-I. However, an in depth study with a larger set of sample is necessary.

Chhabra, S.; Narang, R.; Lakshmy, R.; Das, N.

2005-01-01

406

Measurement of Isotope Shifts, Hyperfine Splittings and Stark Shift for the Ytterbium (6S)2 SINGLET-S(0) to (6S6P) TRIPLET-P(1) Transition Using AN Acousto-Optically Modulated Laser Beam.  

NASA Astrophysics Data System (ADS)

Accurate measurements of isotope shifts, hyperfine splittings and Stark shifts are of interest for studying atomic structure. This thesis reports a new method to precisely measure small frequency intervals. This was done using an acousto-optic modulator to frequency shift part of a laser beam. The frequency shifted and unshifted laser beams were then superimposed and excited an atomic beam. The laser frequency was scanned across the transition while fluorescence produced by the radiative decay of the excited state was detected by a photomultiplier. Each transition generated two peaks in the spectrum separated by the acousto-optic modulation frequency, which permitted the frequency to be calibrated. This method was tested by measuring the isotope shifts and hyperfine splittings of the ytterbium rm (6s)^2 ^1S_0to(6s6p) ^3P_1 transition at 555.6 nm. The shifts (MHz) relative to ^{176} Yb are: ^{173}Yb {it F}=7/2,-1432.1+/-1.2; ^{171}Yb {it F}=1/2, -1176.9+/-1.1; ^{174}Yb, 953.8+/-1.0; ^{172}Yb 1953.9+/-1.6; ^{170}Yb 3240.4+/-2.8; ^{173}Yb {it F}=5/2,3265.8+/-2.8; ^ {168}Yb, 4611.9+/-4.4; ^ {171,173}Yb {it F}=3/2,4760.1 +/-3.7 where the negative sign indicates that the transition occurs at a lower frequency than in ^{176}Yb. The magnetic dipole (a) and electric quadrupole (b) hyperfine coupling constants (MHz) of the (6s6p) ^3P_1 state for ^{171,173}Yb were determined to be a_{171}=3959.1 +/-3.0, a_{173}=-1094.44+/-0.84 and b_{173}=-827.89+/-0.85. These results were in agreement with the most accurate data found in the literature that were obtained by measuring frequency shifts using a Fabry Perot etalon whose length was stabilized with a helium neon laser locked to an iodine line. In contrast, our method uses cheaper and simpler apparatus. Next, the Stark shift of the ytterbium rm (6s)^2 ^1S_0to(6s6p) ^3P_1 transition was measured by passing the atomic beam through a uniform electric field. The Stark shift rate was found to be -15.419+/-0.048 kHz/(kV/cm)^2. No previous measurements of this quantity were found in the literature. In addition, the tensor polarizability of the rm (6s6p) ^3P_1 state was determined to be 5.81+/-0.13 kHz/(kV/cm) ^2 which is more precise than previously found.

Li, Jian

407

[175 years of the National Library of Medicine, of the United States of America: a scientific and cultural treasure worthy of admiration].  

PubMed

The National Library of Medicine (NLM) of the United States of America, celebrates in 2011 its 175th anniversary. This Library, the largest biomedical library in the world, has a proud and rich history serving the health community and the public, especially since its transfer to the National Institutes of Health in Bethesda, Maryland, in 1968. It holds 17 million publications in 150 languages, and has an important collection of ancient and modern historical books as well as original publications of Vesalius and other founders of biomedicine. Its modern document collections illustrate the progress of medical sciences. These collections include laboratory notes from many scientists whose work forms the foundations of contemporary life sciences. The Library also provides several services for health research and for the public, including databases and services such as MedLine and BLAST. The NLM constantly strives to fulfill the information needs of its customers, whether scientists or the public at large. For example, as the Hispanic population of the Unites States has increased in recent years, the NLM has made larger and larger amounts of data available in Spanish to fulfill the health information needs of this population. NLM programs train professionals in library science and biomedical informatics and link biomedical libraries of 18 academic centers throughout the United States. The NLM funds competitive grants for training at the Library, organizing short instruction courses about library science and informatics, and writing books on health related matters including the history of medicine and public health. The NLM is managed and maintained by an outstanding and farsighted group of professionals and dedicated support staff. Their focus on serving and reaching both the biomedical community and the public at large has been crucial to its development into a world icon of biomedical sciences, information technology and the humanities. PMID:22215388

Cabello C, Felipe

2011-09-01

408

APOA1-75 G to A substitution associated with severe forms of CAD, lower levels of HDL and apoA-I among northern Indians.  

PubMed

Apolipoprotein A-I (APOA1 gene, apoA-I protein) is the major protein for plasma high density lipoprotein (HDL). The relationship of APOA1-75G/A polymorphism with lipid profile and coronary artery disease (CAD) is unclear. Out of 370 individuals initially recruited, 164 angiographically proven CAD patients (>/= 70% stenosis) and 36 individuals with normal coronaries or insignificant CAD (NCAD,

Chhabra, S; Narang, R; Lakshmy, R; Das, N

2005-01-01

409

The importance of record length in estimating the magnitude of climatic changes: an example using 175 years of lake ice-out dates in New England  

USGS Publications Warehouse

Many studies have shown that lake ice-out (break-up) dates in the Northern Hemisphere are useful indicators of late winter/early spring climate change. Trends in lake ice-out dates in New England, USA, were analyzed for 25, 50, 75, 100, 125, 150, and 175 year periods ending in 2008. More than 100 years of ice-out data were available for 19 of the 28 lakes in this study. The magnitude of trends over time depends on the length of the period considered. For the recent 25-year period, there was a mix of earlier and later ice-out dates. Lake ice-outs during the last 50 years became earlier by 1.8 days/decade (median change for all lakes with adequate data). This is a much higher rate than for longer historical periods; ice-outs became earlier by 0.6 days/decade during the last 75 years, 0.4 days/ decade during the last 100 years, and 0.6 days/decade during the last 125 years. The significance of trends was assessed under the assumption of serial independence of historical ice-out dates and under the assumption of short and long term persistence. Hypolimnion dissolved oxygen (DO) levels are an important factor in lake eutrophication and coldwater fish survival. Based on historical data available at three lakes, 32 to 46 % of the interannual variability of late summer hypolimnion DO levels was related to ice-out dates; earlier ice-outs were associated with lower DO levels.

Hodgkins, Glenn A.

2013-01-01

410

A fluorescent curcumin-based Zn(II)-complex reactivates mutant (R175H and R273H) p53 in cancer cells  

PubMed Central

Background Mutations of the p53 oncosuppressor gene are amongst the most frequent aberration seen in human cancer. Some mutant (mt) p53 proteins are prone to loss of Zn(II) ion that is bound to the wild-type (wt) core, promoting protein aggregation and therefore unfolding. Misfolded p53 protein conformation impairs wtp53-DNA binding and transactivation activities, favouring tumor growth and resistance to antitumor therapies. Screening studies, devoted to identify small molecules that reactivate mtp53, represent therefore an attractive anti-cancer therapeutic strategy. Here we tested a novel fluorescent curcumin-based Zn(II)-complex (Zn-curc) to evaluate its effect on mtp53 reactivation in cancer cells. Methods P53 protein conformation was examined after Zn-curc treatment by immunoprecipitation and immunofluorescence assays, using conformation-specific antibodies. The mtp53 reactivation was evaluated by chromatin-immunoprecipitation (ChIP) and semi-quantitative RT-PCR analyses of wild-type p53 target genes. The intratumoral Zn-curc localization was evaluated by immunofluorescence analysis of glioblastoma tissues of an ortothopic mice model. Results The Zn-curc complex induced conformational change in p53-R175H and -R273H mutant proteins, two of the most common p53 mutations. Zn-curc treatment restored wtp53-DNA binding and transactivation functions and induced apoptotic cell death. In vivo studies showed that the Zn-curc complex reached glioblastoma tissues of an ortothopic mice model, highlighting its ability to crossed the blood-tumor barrier. Conclusions Our results demonstrate that Zn-curc complex may reactivate specific mtp53 proteins and that may cross the blood-tumor barrier, becoming a promising compound for the development of drugs to halt tumor growth.

2013-01-01

411

Reconnaissance of the ? Pictoris system down to 1.75 AU with the L' - b and vector vortex coronagraph on VLT/NACO  

NASA Astrophysics Data System (ADS)

High contrast imaging has thoroughly combed through the limited parameter space accessible with first-generation ground-based adaptive optics instruments and the HST. Only a few objects were discovered, and many non-detections reported and statistically interpreted. The field is now in need of a technological breakthrough. We aim at opening a new parameter space with first-generation systems such as NACO at the Very Large Telescope, by providing ground-breaking inner working angle (IWA) capabilities in the L' band. This mid-infrared wavelength range is a sweet spot for high contrast coronagraphy since the planets-to-star brightness ratio is favorable, while Strehl ratio is naturally higher. An annular groove phase mask (AGPM) vector vortex coronagraph optimized for the L' band, made out of diamond subwavelength gratings has been manufactured and qualified in the lab. The AGPM enables high contrast imaging at very small IWA (here 0".09), potentially being the key to a new parameter space. Here we present the results of the installation and successful commissioning of an L'- band AGPM on VLT/NACO. During a recent science verification run, we imaged the inner regions of Beta Pictoris down to the previously unexplored projected radius of 1.75 AU with unprecedented point source sensitivity. The disk was also clearly resolved down to its inner truncation . The new NACO mode is an opportunity to introduce a more rigorous framework for deriving detection limits at very small angles, which is also relevant for SPHERE and GPI and every high contrast imaging instrument with small IWA ambitions. Indeed, classical tools assuming Gaussian statistics, perfectly valid at large separations, loose significance close to the center simply because the sample size decreases dramatically (fewer resolution elements at a given radius). Moreover, the probability density function (PDF) of speckle noise and associated confidence level for detection depend on radius. ADI was shown to transform speckles'modified Rician PDF into quasi-Gaussian PDF at large separations, but it is expected that this property of ADI does not hold true at small angles. Finally, the flux attenuation induced by ADI, potentially significant at small angles, does not scale linearly with the companion brightness, which makes its calibration more difficult.

Milli, J.; Absil, O.; Mawet, D.; Lagrange, A.-M.

2013-09-01

412

The VIMOS VLT deep survey. First epoch VVDS-deep survey: 11 564 spectra with 17.5 ? IAB ? 24, and the redshift distribution over 0 ? z ? 5  

NASA Astrophysics Data System (ADS)

This paper presents the “First Epoch” sample from the VIMOS VLT Deep Survey (VVDS). The VVDS goals, observations, data reduction with the VIPGI pipeline and redshift measurement scheme with KBRED are discussed. Data have been obtained with the VIsible Multi Object Spectrograph (VIMOS) on the ESO-VLT UT3, allowing us to observe ?600 slits simultaneously at a spectral resolution R?230. A total of 11 564 objects have been observed in the VVDS-02h and VVDS-CDFS “Deep” fields over a total area of 0.61 deg^2, selected solely on the basis of apparent magnitude 17.5 ? IAB ? 24. The VVDS efficiently covers the redshift range 0 < z ? 5. It is successfully going through the “redshift desert” 1.523.5, probing the bright star-forming population of galaxies. This sample provides an unprecedented dataset to study galaxy evolution over ~90% of the life of the universe.

Le Fèvre, O.; Vettolani, G.; Garilli, B.; Tresse, L.; Bottini, D.; Le Brun, V.; Maccagni, D.; Picat, J. P.; Scaramella, R.; Scodeggio, M.; Zanichelli, A.; Adami, C.; Arnaboldi, M.; Arnouts, S.; Bardelli, S.; Bolzonella, M.; Cappi, A.; Charlot, S.; Ciliegi, P.; Contini, T.; Foucaud, S.; Franzetti, P.; Gavignaud, I.; Guzzo, L.; Ilbert, O.; Iovino, A.; McCracken, H. J.; Marano, B.; Marinoni, C.; Mathez, G.; Mazure, A.; Meneux, B.; Merighi, R.; Paltani, S.; Pellò, R.; Pollo, A.; Pozzetti, L.; Radovich, M.; Zamorani, G.; Zucca, E.; Bondi, M.; Bongiorno, A.; Busarello, G.; Lamareille, F.; Mellier, Y.; Merluzzi, P.; Ripepi, V.; Rizzo, D.

2005-09-01

413

Non-linear permittivity study of the crossover from ferroelectric to relaxor and cluster glass in BaTi1-xSnxO3 (x = 0.175-0.30)  

NASA Astrophysics Data System (ADS)

The electric susceptibilities ?1, ?2, and ?3 of BaTi1-xSnxO3 ceramics with 0.175 ? x ? 0.30 are measured at 90 ? T ? 350 K and 37 ? f ? 106 Hz. Crossover from ferroelectric (x = 0.175) to relaxor behavior (x = 0.30) via coexistence of both (x = 0.25) is indicated by increasing polydispersivity and suppression of ?2 intensity. The relaxor properties are due to weak random fields acting on dipolar Ti4+ clusters in non-polar Sn4+ environment. Upon cooling frustrated interaction between the blocked polar nanoregions yields a cluster glass ground state for x = 0.30 as verified by the dynamic criticality of ?1, ?3, and the scaled non-linear susceptibility a3.

Kleemann, W.; Miga, S.; Xu, Z. K.; Lu, S. G.; Dec, J.

2014-05-01

414

Structural Details of a Calcium-induced Molecular Switch: X-ray Crystallographic Analysis of the Calcium-saturated N-Terminal Domain of Troponin C at 1.75 AResolution  

Microsoft Academic Search

We have solved and refined the crystal and molecular structures of the calcium-saturated N-terminal domain of troponin C (TnC) to 1.75 Aresol- ution. This has allowed for the first detailed analysis of the calcium bind- ing sites of this molecular switch in the calcium-loaded state. The results provide support for the proposed binding order and qualitatively, for the affinity of

Natalie C. J. Strynadka; Maia Cherney; Anita R. Sielecki; Monica X. Li Lawrenc; G. James

415

Incoherent-to-coherent crossover of optical spectra in La0.825Sr0.175MnO3: Temperature-dependent reflectivity spectra measured on cleaved surfaces  

NASA Astrophysics Data System (ADS)

Optical reflectivity spectra were measured on cleaved surfaces of La0.825Sr0.175MnO3 single crystals (TC=283 K) over a temperature range 10-295 K. The optical conductivity ?(?) shows incoherent-to-coherent crossover with decreasing temperature. The minimum metallic conductivity ?min of this compound was determined by the dc resistivity ?(T) measurements of Al-substituted crystals (La0.825Sr0.175)(Mn1-zAlz)O3 and was found to be 2000-3000 ?-1 cm-1. This indicates that the dc conductivity of La0.825Sr0.175MnO3 is smaller than ?min over a wide temperature range below TC even though ?(T) is metallic (d?/dT>0). The present results suggest that there are two types of the ferromagnetic-metallic phase below TC-a ``high-temperature incoherent'' metallic (HIM) and a ``low-temperature coherent'' metallic phase. ``Colossal magnetoresistance'' is a characteristic of the HIM phase.

Takenaka, K.; Sawaki, Y.; Sugai, S.

1999-11-01

416

New yellow-emitting Whitlockite-type structure Sr(1.75)Ca(1.25)(PO4)2:Eu(2+) phosphor for near-UV pumped white light-emitting devices.  

PubMed

New compound discovery is of interest in the field of inorganic solid-state chemistry. In this work, a whitlockite-type structure Sr1.75Ca1.25(PO4)2 newly found by composition design in the Sr3(PO4)2-Ca3(PO4)2 join was reported. Crystal structure and luminescence properties of Sr1.75Ca1.25(PO4)2:Eu(2+) were investigated, and the yellow-emitting phosphor was further employed in fabricating near-ultraviolet-pumped white light-emitting diodes (w-LEDs). The structure and crystallographic site occupancy of Eu(2+) in the host were identified via X-ray powder diffraction refinement using Rietveld method. The Sr1.75Ca1.25(PO4)2:Eu(2+) phosphors absorb in the UV-vis spectral region of 250-430 nm and exhibit an intense asymmetric broadband emission peaking at 518 nm under ?ex = 365 nm which is ascribed to the 5d-4f allowed transition of Eu(2+). The luminescence properties and mechanism are also investigated as a function of Eu(2+) concentration. A white LED device which is obtained by combining a 370 nm UV chip with commercial blue phosphor and the present yellow phosphor has been fabricated and exhibit good application properties. PMID:24773050

Ji, Haipeng; Huang, Zhaohui; Xia, Zhiguo; Molokeev, Maxim S; Atuchin, Victor V; Fang, Minghao; Huang, Saifang

2014-05-19

417

Bis(pentamethylcyclopentadienyl)ytterbium(II) as a Lewis acid and electron-transfer ligand: preparation and crystal structures of (Yb(MeâCâ)â(. mu. CO)\\/sub x\\/Mn(CO)\\/sub 5-x\\/)\\/sub y\\/ (x,y = 2; x = 3, y = infinity)  

Microsoft Academic Search

The divalent ytterbium metallocene (MeâCâ)âYb(OEtâ) reacts with Mnâ(CO)ââ to give a compound of composition (MeâCâ)âYbMn(CO)â¹\\/âPhMe, which was shown by an X-ray crystallographic study to be composed of a polymeric chain of ((MeâCâ)âYb(..mu..-OC)âMn(CO)â) units with dimeric units (MeâCâ)âYb(..mu..-OC)âMn(CO)â) packed between the polymeric sheets. The toluene of solvation fills regularly spaced voids in the network of dimer and polymer sheets. The space

J. M. Boncella; R. A. Andersen

1984-01-01

418

Structure and NIR-luminescence of ytterbium(III) beta-diketonate complexes with 5-nitro-1,10-phenanthroline ancillary ligand: assessment of chain length and fluorination impact.  

PubMed

Seven new tris(?-diketonear-nate)ytterbium(III) complexes with the general formula [Yb(?-diketonate)3(5NO2phen)] (where the ?-diketone is either 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione, 4,4,4-trifluoro-1-(2-furyl)-1,3-butanedione, 1,1,1-trifluoro-2,4-pentanedione, 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione, 1,1,1,5,5,6,6,7,7,7-decafluoro-2,4-heptanedione, 2,4-hexanedione or 2,6-dimethyl-3,5-heptanedione, and 5NO2phen = 5-nitro-1,10-phenanthroline) were synthesized and characterized by elemental analysis, attenuated total reflectance Fourier transform infrared spectroscopy and photoluminescence spectroscopy. Single crystal X-ray structures have been determined for three fluorinated complexes and ground state geometries of the other four complexes have been predicted using the Sparkle/PM6 model. These experimental structures and those designed by semi-empirical models reveal octacoordination around the Yb(3+) ion. Photoluminescence studies and lifetime measurements show that the increase in the fluorinated ?-diketonate chain length is associated with a decrease in Yb(3+) luminescence intensity of the (2)F5/2?(2)F7/2 transition at around 980 nm and the (2)F5/2 excited state lifetime, while the ligand lifetime value remains almost unaffected. Finally, fluorination of the ligands is only advised when the complexes are to be used for co-doping with isostructural Er(3+) complexes for optical amplifiers, since it leads to a slight decrease in luminescence intensity for the same ?-diketonate chain length. PMID:23900403

Martín-Ramos, Pablo; Pereira da Silva, Pedro S; Lavín, Victor; Martín, Inocencio R; Lahoz, Fernando; Chamorro-Posada, Pedro; Silva, Manuela Ramos; Martín-Gil, Jesús

2013-10-01

419

Pd{sub 30}Pt{sub 17.5}Cu{sub 32.5}P{sub 20} alloy with low critical cooling rate of 0.067 K/s  

SciTech Connect

In order to realize biomedical applications of bulk glassy alloys, Pd-based glassy alloys with Ni-free composition were developed. The alloy with the highest glass-forming ability was obtained at a composition of Pd{sub 30}Pt{sub 17.5}Cu{sub 32.5}P{sub 20}. The critical cooling rate for glass formation was measured to be 0.050-0.067 K/s. It is also recognized that the crystallization of the undercooled alloy is mainly dominated by surface nucleation. The apparent crystal growth rate of the alloy was slightly higher than that of the previously reported Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} alloy at the same degree of undercooling. The highly processable feature of the alloy has potential for biomedical applications.

Nishiyama, N.; Takenaka, K.; Inoue, A. [RIMCOF Tohoku University Laboratory, R and D Institute of Metals and Composites for Future Industries, Sendai 980-8577 (Japan); Graduate School, Tohoku University, Sendai 980-8577 (Japan); Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

2006-03-20

420

Both mature miR-17-5p and passenger strand miR-17-3p target TIMP3 and induce prostate tumor growth and invasion  

PubMed Central

MicroRNAs (miRNA) precursor (pre-miRNA) molecules can be processed to release a miRNA/miRNA* duplex. In the canonical model of miRNA biogenesis, one strand of the duplex is thought to be the biologically active miRNA, whereas the other strand is thought to be inactive and degraded as a carrier or passenger strand called miRNA* (miRNA star). However, recent studies have revealed that miRNA* strands frequently play roles in the regulatory networks of miRNA target molecules. Our recent study indicated that miR-17 transgenic mice could abundantly express both the mature miR-17-5p and the passenger strand miR-17-3p. Here, we showed that miR-17 enhanced prostate tumor growth and invasion by increasing tumor cell proliferation, colony formation, cell survival and invasion. miRNA target analysis showed that both miR-17-5p and miR-17-3p repressed TIMP metallopeptidase inhibitor 3 (TIMP3) expression. Silencing with small interfering RNA against TIMP3 promoted cell survival and invasion. Ectopic expression of TIMP3 decreased cell invasion and cell survival. Our results demonstrated that mature miRNA can function coordinately with its passenger strand, enhancing the repressive ability of a miRNA by binding the same target. Within an intricate regulatory network, this may be among the mechanisms by which miRNA can augment their regulatory capacity.

Yang, Xiangling; Du, William W.; Li, Haoran; Liu, Fengqiong; Khorshidi, Anna; Rutnam, Zina Jeyapalan; Yang, Burton B.

2013-01-01

421

Quantum Simulation of Magnetism with Ytterbium Ions  

Microsoft Academic Search

An array of cold trapped ions has recently been identified as a promising physical implementation of a quantum simulator [1,2], thanks to the tunable long range couplings between ions and its advanced status on quantum computation applications. In particular, ions coupled by tightly bound transverse normal modes allows more efficient cooling and wide tunability of the effective spin-spin couplings. We

Ming-Shien Chang; Kihwan Kim; Simcha Korenblit; Kazi Islam; Christopher Monroe

2009-01-01

422

Magnetostriction of Ytterbium and Cerium in Yig.  

National Technical Information Service (NTIS)

Measurements using strain gauges of the magnetostriction constants of Yb(3+) and Ce(3+) ions in YIG are presented. The temperature dependence of the magnetostriction for Yb(3+) in YIG is compared to theories by Callen and Callen based on crystal-field (si...

R. L. Comstock J. J. Raymond

1967-01-01

423

BASIC CHLORIDE SALTS OF ERBIUM AND YTTERBIUM  

Microsoft Academic Search

The formation of basic salts is indicated by the fact that a rare earth ; salt can be completely precipitated by less than 3.0 equivalents of NaOH. To ; determine the composition and activity product of the insoluble basic salts, it ; was necessary to measure chloride activity with a silver chloride or calomel ; electrcde and hydroxide activity by

N. V. Akselrud; V. B. Spivakovskii

1960-01-01

424

40 CFR 763.175 - Enforcement.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) TOXIC SUBSTANCES CONTROL ACT ASBESTOS Prohibition of the Manufacture...and Distribution in Commerce of Certain Asbestos-Containing Products; Labeling Requirements...processing, or distribution in commerce of asbestos-containing products in violation...

2013-07-01

425

33 CFR 175.23 - Serviceable condition.  

Code of Federal Regulations, 2013 CFR

...that has become hardened, non-resilient, permanently compressed, waterlogged, oil-soaked, or which shows evidence of fungus or mildew; or (3) Loss of buoyant material or buoyant material that is not securely held in position. (c) In...

2013-07-01

426

33 CFR 175.105 - Definitions.  

Code of Federal Regulations, 2013 CFR

...means: (1) The U.S. waters of the Great Lakes (Lake Erie, Huron, Michigan, Ontario, and Superior); (2) The territorial seas...Those waters directly connected to the Great Lakes and territorial seas (i.e. ,...

2013-07-01

427

21 CFR 169.175 - Vanilla extract.  

...vanilla extract or concentrated vanilla flavoring or vanilla flavoring concentrated to the semisolid form called vanilla oleo-resin. Vanilla extract may contain one or more of the following optional ingredients: (1) Glycerin. (2) Propylene...

2014-04-01

428

21 CFR 175.250 - Paraffin (synthetic).  

Code of Federal Regulations, 2013 CFR

...exceeding 0.01 as determined by ASTM method E131-81a, âStandard Definitions of Terms and Symbols Relating to Molecular-Spectroscopy,â which is incorporated by reference. See paragraph (b)(1) of this section for availability of the...

2013-04-01

429

175Hp Contrarotating Homopolar Motor Design Report.  

National Technical Information Service (NTIS)

A normally conducting contrarotating homopolar motor has been designed and constructed. The reaction torque, in the outer rotor, from the inner rotor is utilized to produce true contrarotation. The machine utilizes liquid cooled conductors, high performan...

M. J. Cannell J. L. Drake R. A. McConnell W. R. Martino

1994-01-01

430

25 CFR 175.30 - Billing.  

Code of Federal Regulations, 2011 CFR

...on the pattern of the customer's prior consumption, or on an estimate of the customer's electric load where no billing history exists. (b) Unmetered customers. Bills shall be determined and rendered as provided in the customer's special...

2011-04-01

431

25 CFR 175.23 - Customer responsibilities.  

Code of Federal Regulations, 2011 CFR

...Comply with the National Electrical Manufacturers Association Standards and/or the National Electrical Code of the National Board of Fire Underwriters for Electric Wiring and Apparatus as they apply to the installation and operation of customer-owned...

2011-04-01

432

21 CFR 558.175 - Clopidol.  

Code of Federal Regulations, 2010 CFR

...chickens intended for use as caged layers: As an aid in the prevention...infectious synovitis caused by Mycoplasma synoviae susceptible to chlortetracycline...chickens intended for use as caged layers: As in paragraph (d...chickens intended for use as caged layers: As in paragraph...

2010-04-01

433

21 CFR 558.175 - Clopidol.  

Code of Federal Regulations, 2010 CFR

...chickens intended for use as caged layers: As an aid in the prevention...infectious synovitis caused by Mycoplasma synoviae susceptible to chlortetracycline...chickens intended for use as caged layers: As in paragraph (d...chickens intended for use as caged layers: As in paragraph...

2009-04-01

434

33 CFR 175.201 - Ventilation.  

Code of Federal Regulations, 2013 CFR

...Ventilation. No person may operate a boat built after July 31, 1980, that has a gasoline engine for electrical generation, mechanical power, or propulsion unless it is equipped with an operable ventilation system that meets the requirements...

2013-07-01

435

33 CFR 175.105 - Definitions.  

Code of Federal Regulations, 2011 CFR

... means: (1) The U.S. waters of the Great Lakes (Lake Erie, Huron, Michigan, Ontario, and Superior); (2) The territorial...3) Those waters directly connected to the Great Lakes and territorial seas (i.e. ,...

2011-07-01

436

33 CFR 175.105 - Definitions.  

Code of Federal Regulations, 2012 CFR

... means: (1) The U.S. waters of the Great Lakes (Lake Erie, Huron, Michigan, Ontario, and Superior); (2) The territorial...3) Those waters directly connected to the Great Lakes and territorial seas (i.e. ,...

2012-07-01

437

33 CFR 175.105 - Definitions.  

Code of Federal Regulations, 2010 CFR

... means: (1) The U.S. waters of the Great Lakes (Lake Erie, Huron, Michigan, Ontario, and Superior); (2) The territorial...3) Those waters directly connected to the Great Lakes and territorial seas (i.e. ,...

2010-07-01

438

21 CFR 175.105 - Adhesives.  

Code of Federal Regulations, 2013 CFR

...of this chapter Butyl benzoate Butyl benzyl phthalate Butyldecyl phthalate 1,3-Butylene glycoldiglycolic acid copolymer...butyl-m- cresol) Butyl lactate Butyloctyl phthalate p-tert- Butylphenyl salicylate...

2013-04-01

439

49 CFR 175.705 - Radioactive contamination.  

Code of Federal Regulations, 2010 CFR

...aircraft operator shall notify the offeror at the earliest practicable moment following any incident in which there has been breakage, spillage, or suspected radioactive contamination involving Class 7 (radioactive) materials...

2010-10-01

440

21 CFR 175.105 - Adhesives.  

Code of Federal Regulations, 2010 CFR

...borate Ammonium citrate Ammonium persulfate Ammonium polyacrylate Ammonium potassium... Potassium permanganate Potassium persulfate Potassium phosphates (mono-, di...preservative only. Sodium perborate Sodium persulfate Sodium μ-phenylphenate For...

2009-04-01

441

21 CFR 175.105 - Adhesives.  

Code of Federal Regulations, 2010 CFR

...borate Ammonium citrate Ammonium persulfate Ammonium polyacrylate Ammonium potassium... Potassium permanganate Potassium persulfate Potassium phosphates (mono-, di...preservative only. Sodium perborate Sodium persulfate Sodium μ-phenylphenate For...

2010-01-01

442

21 CFR 175.105 - Adhesives.  

Code of Federal Regulations, 2011 CFR

...acid, homopolymer, sodium salt (CAS Reg. No. 35641-59-9...dimethylidiallyl ammonium chloride) sodium salt (CAS Reg. No. 72275-68-4...including alkyd type), as the basic polymer, formed as esters...50975-82-1) and/or its sodium salt (CAS Reg. No....

2011-04-01

443

21 CFR 175.105 - Adhesives.  

Code of Federal Regulations, 2012 CFR

...acid, homopolymer, sodium salt (CAS Reg. No. 35641-59-9...dimethylidiallyl ammonium chloride) sodium salt (CAS Reg. No. 72275-68-4...including alkyd type), as the basic polymer, formed as esters...50975-82-1) and/or its sodium salt (CAS Reg. No....

2012-04-01

444

Linear, non-linear optical susceptibilities and the hyperpolarizability of the mixed crystals Ag(0.5)Pb(1.75)Ge(S(1-x)Se(x))4: experiment and theory.  

PubMed

As the starting point for a comprehensive theoretical investigation of the linear and nonlinear optical susceptibilities, we have used our experimental crystallographic data for Ag0.5Pb1.75GeS3Se (Ag2Pb7Ge4S12Se4) reported. The experimental crystallographic positions were optimized by minimizing the forces acting on each atom to get meaningful theoretical predictions of the optical properties. The linear optical susceptibilities are calculated. We find that the optical band gap shows very good agreement with our measured gap. The second-order nonlinear optical (NLO) susceptibilities dispersion namely the optical second harmonic generation (SHG) is calculated and compared with our experimental measurements. The microscopic first order hyperpolarizability, ?123, vector component along the principal dipole moment directions for the ?((2))(123)(?) component was obtained theoretically and compared with our measured values at different temperatures. The dependence of the two-photon absorption (TPA) for the pump-probing at SHG of the microsecond CO2 laser was measured. In addition we explored the linear electro-optical effect in these crystals. This effect is described by the third rank polar tensors similarly to the SHG. However, for the Pockels effect besides the electronic contribution, the phonon subsystem also begins to play a principal role. As a consequence we study the dispersion of the linear electro-optical effects in the mentioned crystals. PMID:24097293

Reshak, A H; Kogut, Y M; Fedorchuk, A O; Zamuruyeva, O V; Myronchuk, G L; Parasyuk, O V; Kamarudin, H; Auluck, S; Plucinski, K J; Bila, Jiri

2013-11-21

445

Effect of oxygen on phase formation and thermal stability of slowly cooled Zr{sub 65}Al{sub 7.5}Cu{sub 17.5}Ni{sub 10} metallic glass  

SciTech Connect

The effect of small amounts of oxygen (0.28--0.6 at.%) on the phase formation and the thermal stability of bulk samples of the Zr{sub 65}Al{sub 7.5}Cu{sub 17.5}Ni{sub 10} alloy prepared by die casting into a copper mould has been studied by X-ray diffraction, microstructural characterization and differential scanning calorimetry. In contrast to rapidly quenched ribbons, the crystalline volume fraction in slowly cooled bulk samples increases with increasing oxygen content. Oxygen triggers the formation of a metastable f.c.c. NiZr{sub 2}-type crystalline phase which also depends on the local cooling conditions during casting. The processes o the oxygen-induced crystallization are discussed in detail considering initial nucleation of metastable f.c.c. crystalline phases. Furthermore, there is a strong influence of the oxygen content on the thermal stability during constant-rate heating to elevated temperatures. With increasing oxygen content a drastic reduction of the supercooled liquid region is observed, resulting mainly from a change of the crystallization sequence from a single- to a double-step process which is attributed to the oxygen-triggered formation and the subsequent transformation of the metastable f.c.c. phase.

Gebert, A.; Eckert, J.; Schultz, L. [IFW Dresden (Germany). Inst. fuer Metallische Werkstoffe] [IFW Dresden (Germany). Inst. fuer Metallische Werkstoffe

1998-09-18

446

Magnetic field effect on Fe-induced short-range magnetic correlation and electrical conductivity in Bi1.75Pb0.35Sr1.90Cu0.91Fe0.09O6+y  

SciTech Connect

We report electrical-resistivity measurements and neutron-diffraction studies under magnetic fields of Bi{sub 1.75}Pb{sub 0.35}Sr{sub 1.90}Cu{sub 0.91}Fe{sub 0.09}O{sub 6+y}, in which hole carriers are overdoped. This compound shows short-range incommensurate magnetic correlation with incommensurability {delta} = 0.21, whereas a Fe-free compound shows no magnetic correlation. Resistivity shows an up turn at low temperature in the form of ln(1/T) and shows no superconductivity. We observe reduction in resistivity by applying magnetic fields (i.e., a negative magnetoresistive effect) at temperatures below the onset of short-range magnetic correlation. Application of magnetic fields also suppresses the Fe-induced incommensurate magnetic correlation. We compare and contrast these observations with two different models: (1) stripe order and (2) dilute magnetic moments in a metallic alloy with associated Kondo behavior. The latter picture appears to be more relevant to the present results.

Wakimoto, S [Japan Atomic Energy Agency (JAEA); Hiraka, Haruhiro [Institute for Materials Research, Tohoku University, Sendai, Japan; Kudo, Kazutaka [Institute for Materials Research, Tohoku University, Sendai, Japan; Okamoto, Daichi [Institute for Materials Research, Tohoku University, Sendai, Japan; Nishizaki, Terukazu [Institute for Materials Research, Tohoku University, Sendai, Japan; Kakurai, Kazuhisa [Japan Atomic Energy Agency (JAEA); Hong, Tao [ORNL; Zheludev, Andrey [Laboratory for Neutron Scattering ETHZ & PSI; Tranquada, John M. [Brookhaven National Laboratory (BNL); Kobayashi, Norio [Institute for Materials Research, Tohoku University, Sendai, Japan; Yamada, Kazuyoshi [Institute for Materials Research, Tohoku University, Sendai, Japan

2010-08-01

447

Laser spectroscopy of holmium monosulphide: Hyperfine structure in the A[14.79]8.5, X18.5, X27.5 and W17.5 states  

NASA Astrophysics Data System (ADS)

Laser induced fluorescence spectra, using a single frequency ring dye laser, have shown hyperfine structure in transitions from the A[14.79]8.5 state of HoS to three low-lying electronic states, X18.5, X27.5 and W17.5. Analysis of the hyperfine structure yielded magnetic hyperfine parameters, h(X1) = 0.3298(27) cm-1, h(X2) = 0.1124(29) cm-1, h(W1) = 0.275(5) cm-1 and h(A) = 0.2314(25) cm-1. The three low lying states originate from the ground Ho2+{4f10(5I8)6s}S2- configuration and the hyperfine parameters were used to determine the free Ho2+ ion quantum numbers appropriate to each state as well as the approximate relative contributions of the 4f and 6s electrons to the overall hyperfine energy. Calculation of the ground state magnetic hyperfine parameter h(X18.5) from atomic hyperfine parameters was found to be consistent with the observed values.

Linton, C.

2014-07-01

448

Positron-annihilation studies of free-volume changes in the bulk metallic glass Zr65Al7.5Ni10Cu17.5 during structural relaxation and at the glass transition  

NASA Astrophysics Data System (ADS)

Volume changes in Zr65Al7.5Ni10Cu17.5 bulk metallic glass have been observed by positron annihilation and density measurements. Excess volume of the order of 0.1% is quenched in the bulk glass at cooling rates as low as 1-2 K/s. The isothermal relaxation kinetics below the glass transition temperature obey a Kohlrausch law with ? exponents of ?0.3 between 230 and 290 °C. The effective activation energy for relaxation is (1.2+/-0.2) eV. Stress-strain measurements indicate that structural relaxation is not accompanied by embrittlement. It is shown that the outer surface plays a crucial role in the annealing of excess volume. Free volume can be restored by a heat treatment in the undercooled liquid state. The observed free volume changes contrast with the behavior of perfectly strong glasses. The temperature dependence of the positron lifetime can be explained by thermal detrapping of the positrons from shallow traps.

Nagel, C.; Rätzke, K.; Schmidtke, E.; Faupel, F.; Ulfert, W.

1999-10-01

449

Apoptosis induction by antisense oligonucleotides against miR-17-5p and miR-20a in lung cancers overexpressing miR-17-92.  

PubMed

Amplification and overexpression of the miR-17-92 microRNAs (miRNA) cluster at 13q31.3 has recently reported, with pointers to functional involvement in the development of B-cell lymphomas and lung cancers. In the present study, we show that inhibition of miR-17-5p and miR-20a with antisense oligonucleotides (ONs) can induce apoptosis selectively in lung cancer cells overexpressing miR-17-92, suggesting the possibility of 'OncomiR addiction' to expression of these miRNAs in a subset of lung cancers. In marked contrast, antisense ONs against miR-18a and miR-19a did not exhibit such inhibitory effects, whereas inhibition of miR-92-1 resulted in only modest reduction of cell growth, showing significant distinctions among miRNAs of the miR-17-92 cluster in terms of their roles in cancer cell growth. During the course of this study, we also found that enforced expression of a genomic region, termed C2, residing 3' to miR-17-92 in the intron 3 of C13orf25 led to marked growth inhibition in association with double stranded RNA-dependent protein kinase activation. Finally, this study also revealed that the vast majority of C13orf25 transcripts are detected as Drosha-processed cleavage products on Northern blot analysis and that a novel polyadenylation site is present 3' to the miR-17-92 cluster and 5' to the C2 region. Taken together, the present findings contribute towards better understanding of the oncogenic roles of miR-17-92, which might ultimately lead to the future translation into clinical applications. PMID:17384677

Matsubara, H; Takeuchi, T; Nishikawa, E; Yanagisawa, K; Hayashita, Y; Ebi, H; Yamada, H; Suzuki, M; Nagino, M; Nimura, Y; Osada, H; Takahashi, T

2007-09-01

450

Thermochromic La{sub 1-x}Sr{sub x}MnO{sub 3} (x=0.1, 0.175, and 0.3) smart coatings grown by reactive pulsed laser deposition  

SciTech Connect

Thermochromic La{sub 1-x}Sr{sub x}MnO{sub 3} (x=0.1, 0.175, and 0.3) (LSMO) smart coatings were synthesized on (100) silicon and (0001) sapphire substrates by means of reactive pulsed laser deposition process at relatively low substrate temperature (500 deg. C) and without postannealing. X-ray diffraction patterns indicated that all deposited LSMO films have polycrystalline structures. The energy dispersive x-ray spectroscopy analysis indicated approximately the same La/Sr ratio in the formed LSMO coatings as in their corresponding targets. While, the x-ray photoelectron spectroscopy analysis of the LSMO/sapphire revealed that the strontium segregate at the film surface. The thermochromism of LSMO coatings was investigated by measuring their infrared reflectance as a function of temperature (up to 160 deg. C). It was observed that the reflectance decreased as the temperature increased. Reflectance switching of about 25% was achieved in La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/Si at a wavelength of 5 {mu}m. The sheet electrical resistivity as a function of temperature (up to 130 deg. C) of LSMO/sapphire was investigated by means of the standard four-point probe technique. The resistivity decreased with increasing the temperature and no metallic-to-insulator transition was observed. However, it is found that the resistivity is very sensitive to the concentration level of Sr dopant: the resistivity decreased as the concentration of Sr increased. In addition, at room temperature, a higher temperature coefficient of resistance of -2.30%/ deg. C was achieved in La{sub 0.9}Sr{sub 0.1}MnO{sub 3} thin films. Finally, these LSMO smart coatings are promising materials for optical switching and IR uncooled bolometer devices.

Soltani, M.; Chaker, M.; Jiang, X.X.; Nikanpour, D.; Margot, J. [INRS-Energie, Materiaux et Telecommunications, 1650 Lionel Boulet, Varennes, Quebec J3X 1S2 (Canada); Canadian Space Agency, 6767 Route de l'Aeroport, Saint-Hubert, Quebec J3Y 8Y9 (Canada); Departement de Physique, Universite de Montreal, C. P. 6128, Succursale Centre-ville, Montreal, Quebec H3C 3J7 (Canada)

2006-07-15

451

Microstructural properties of K0.8 Fe1.6 S2, K0.8 Fe1.75 Se2-y Sy(0 ? y ? 2) and K0.8 Fe1.5+x S2(0 < x ? 0.5) single crystals  

NASA Astrophysics Data System (ADS)

The structural features of the antiferromagnetic K0.8Fe1.6S2 have been studied in the temperature range from 300 K up to 700 K by means of in situ transmission electron microscopy (TEM). The superstructure with a wave vector \\textbf{q}_{1}=1/5(3\\textbf{a}^*+\\textbf{b}^*) originating from a Fe-vacancy order has been clearly observed; moreover, the structural analysis shows that K0.8Fe1.6S2 undergoes a transition from the Fe-vacancy order to disorder at about 585 K. The S substitution effect on the phase separation and superconductivity in the K0.8Fe1.75Se2-ySy materials has been systematically investigated by SEM and TEM structural analyses, as well as by electrical resistivity measurements. Our experimental results reveal that the S element adopts a homogeneous distribution in all investigated materials, and the essential phase-separation nature is very similar to what was observed in the K0.8Fe1.75Se2 superconductor. A phase-separated state formed by the coexistence of two Fe-vacancy orders with wave vectors \\textbf{q}_{1}=1/5(3\\textbf{a}^*+\\textbf{b}^*) and \\textbf{q}_{3}=1/4(3\\textbf{a}^*+\\textbf{b}^*) in K0.8Fe1.5+xS2 (0 < x < 0.1) has been briefly discussed.

Cai, Y.; Wang, Z.; Wang, Z. W.; Sun, Z. A.; Yang, H. X.; Tian, H. F.; Ma, C.; Zhang, B.; Li, J. Q.

2013-08-01

452

Yb:YAG absorption at ambient and cryogenic temperatures  

Microsoft Academic Search

We have performed absorption measurements and generated absorption cross sections as a function of wavelength for the laser material YAG doped with ytterbium at 300, 175, and 75 K. This data was generated to enable a direct comparison of the absorption intensity and linewidths at room and cryogenic temperatures, and in particular near the temperature of liquid nitrogen at 77

David C. Brown; Rufus L. Cone; Yongchen Sun; Randy W. Equall

2005-01-01

453

All fiber ytterbium-doped fiber grating laser  

NASA Astrophysics Data System (ADS)

Based on requirement of all fiber structure, all fiber Yb-doped fiber grating laser uses double cladding fiber with Yb-doped as gain medium, uses fiber grating as resonance cavity and employs semiconductor laser as pumping source to realize the lasing based on the reverse of Yb ion. We use Bragg fiber grating as the resonance cavity of fiber laser and 970nm LD as pumping source, pump the Yb-doped double cladding fiber with circular inner-cladding. We realized 7.5W single-mode laser output, central wavelength of 1080nm, FWHM of 0.11nm under the pump power of 11.8W. Maxim conversion efficiency is 63.5% and slope efficiency of 46.4%.

Zhang, Liang; Qin, Li; Zhang, Jian; Ning, Yong-Qiang; Wang, Lijun

2005-01-01

454

Ytterbium-doped borate fluoride laser crystals and lasers  

DOEpatents

A new class of solid state laser crystals and lasers are formed from Yb-doped borate fluoride host crystals. The general formula for the host crystals is MM'(BO.sub.3)F, where M, M' are monovalent, divalent aria trivalent metal cations. A particular embodiment of the invention is Yb-doped BaCaBO.sub.3 F (Yb:BCBF). BCBF and some of the related derivative crystals are capable of nonlinear frequency conversion, whereby the fundamental of the laser is converted to a longer or shorter wavelength. In this way, these new crystals can simultaneously serve as self-frequency doubling crystals and laser materials within the laser resonator.

Schaffers, Kathleen I. (Pleasanton, CA); DeLoach, Laura D. (Manteca, CA); Payne, Stephen A. (Castro Valley, CA); Keszler, Douglas A. (Corvallis, OK)

1997-01-01

455

Ytterbium-doped borate fluoride laser crystals and lasers  

DOEpatents

A new class of solid state laser crystals and lasers are formed from Yb-doped borate fluoride host crystals. The general formula for the host crystals is MM{prime}(BO{sub 3})F, where M, M{prime} are monovalent, divalent aria trivalent metal cations. A particular embodiment of the invention is Yb-doped BaCaBO{sub 3}F (Yb:BCBF). BCBF and some of the related derivative crystals are capable of nonlinear frequency conversion, whereby the fundamental of the laser is converted to a longer or shorter wavelength. In this way, these new crystals can simultaneously serve as self-frequency doubling crystals and laser materials within the laser resonator. 6 figs.

Schaffers, K.I.; DeLoach, L.D.; Payne, S.A.; Keszler, D.A.

1997-10-14

456

Glasslike thermal conductivity in ytterbium-doped lanthanum zirconate pyrochlore  

Microsoft Academic Search

Glass-like thermal conductivity is observed in (La1?xYbx)2Zr2O7 (1\\/6?x?1\\/3), which exhibits great potential as a high-temperature thermal barrier coating material. In the pyrochlore-type La2Zr2O7, the large 16c-site La3+ is weakly bonded by its surrounding 48f-site oxygen ions, and substitution of La3+ with smaller and heavier Yb3+ gives rise to a large atomic displacement parameter (ADP) of Yb3+ which behaves as a

Chunlei Wan; Wei Zhang; Yifeng Wang; Zhixue Qu; Aibing Du; Ruifen Wu; Wei Pan

2010-01-01

457

Ionization of ytterbium atoms from an excited state  

SciTech Connect

The cross sections of the photoionization and the electron impact-induced ionization of Yb atoms from the excited 6s6p({sup 3}P{sub 1}) state are numerically calculated. Matrix elements are computed in multielectron relativistic and nonrelativistic approximations with allowance for the superposition of configurations and a relaxation effect. The radial part of the electron wavefunction in a continuous spectrum is calculated using the solutions to one-configuration Hartree-Fock and Dirac-Fock equations. The cross sections calculated by a relativistic method are compared to those for a nonrelativistic approximation. The ratios of the radiation reduced matrix elements and the phase shifts of the wavefunctions of a continuous spectrum calculated for the 6p {epsilon}s and 6p {sup {yields} {epsilon}}d transitions are compared to the values obtained by approximating the experimental dependences of the angular distribution of photoelectrons for the photoionization by ultraviolet radiation from an oriented excited state.

Elizarov, A. Yu., E-mail: a.elizarov@mail.ioffe.r [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation); Tupitsyn, I. I., E-mail: tup@tup.usr.pu.r [St. Petersburg State University (Russian Federation)

2010-06-15

458

Density changes of ytterbium trifluoride on phase transitions  

Microsoft Academic Search

The density and thermal expansion of the melt and high-temperature solid phase of YbF3 were studied by a gamma attenuation method. Volume changes on melting and on polymorphic transformation were measured. The density and volume coefficient of the thermal expansion of the liquid at the melting point are equal to 6284 kg m?3 and 14.7 × 10?5 K?1. Relative density

S. V. Stankus; R. A. Khairulin; P. V. Tyagel'sky

1997-01-01

459

Nonlinear optical crystal optimized for ytterbium laser host wavelengths  

DOEpatents

A material for harmonic generation has been made by substitutional changes to the crystal LaCa.sub.4(BO.sub.3).sub.3 also known as LaCOB in the form Re1.sub.xRe2.sub.yRe3.sub.zCa.sub.4(B0.sub.3).sub.3O where Re1 and Re2, (rare earth ion 1 and rare earth ion 2) are selected from the group consisting of Sc, Yttrium, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; Re3 is Lanthanum; and x+y+z=1.

Ebbers, Christopher A. (Livermore, CA); Schaffers, Kathleen I. (Pleasanton, CA)

2007-08-21

460

Nonlinear optical crystal optimized for Ytterbium laser host wavelengths  

DOEpatents

A material for harmonic generation has been made by substitutional changes to the crystal LaCa.sub.4 (BO.sub.3).sub.3 also known as LaCOB in the form Re1.sub.xRe2.sub.yRe3.sub.zCa.sub.4(BO.sub.3).sub.3O where Re1 and Re2, (rare earth ion 1 and rare earth ion 2) are selected from the group consisting of Sc, Yttrium, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; Re3 is Lanthanum; and x+y+z=1.

Ebbers, Christopher A. (Livermore, CA); Schaffers, Kathleen I. (Pleasanton, CA)

2007-02-20

461

Experimental Investigation of Excited-State Lifetimes in Atomic Ytterbium  

SciTech Connect

Lifetimes of 21 excited states in atomic Yb were measured using time-resolved fluorescence detection following pulsed laser excitation. The lifetime of the 4f{sup 14}5d6s {sup 3}D{sub 1} state, which is of particular importance for a proposed study of parity nonconservation in atoms, was measured to be 380(30) ns.

Bowers, C.J.; Budker, D.; Commins, E.D.; DeMille, D.; Freedman, S.J.; Nguyen, A.-T.; Shang, S.-Q.; /UC, Berkeley; Zolotorev, M.; /SLAC

2011-11-15

462

Distribution of ytterbium-169 in rat brain after intravenous injection  

Microsoft Academic Search

It is well known that lanthanides have come into extensive and rapid use in a number of fields. As a result, more and more lanthanides are getting into the environment and food chains. However, the distributions of lanthanides in brain are not yet very clear. In this study, adult Sprague–Dawley male rats were intravenously injected with 0.5ml of 169YbCl3 solution

Haiqing Xiao; Fuliang Li; Zhiyong Zhang; Liuxing Feng; Zijie Li; Juhua Yang; Zhifang Chai

2005-01-01

463

Simulating Quantum Spin Models with Trapped Ytterbium Ions^1  

Microsoft Academic Search

Simulating large quantum many-body systems is practically impossible with classical computers, as it requires resources exponential in the system size. An array of cold trapped ions has recently been identified as a promising candidate for exploring many-body spin Hamiltonians. This is due to superb control of their quantum states and interactions, high-fidelity spin state detection of each and every ion,

M.-S. Chang; K. Kim; S. Korenblit; K. R. Islam; J. D. Sterk; A. Chew; R. Slusher; C. Monroe

2008-01-01

464

Long-range interaction coefficients for ytterbium dimers  

NASA Astrophysics Data System (ADS)

We evaluate the electric-dipole and electric-quadrupole static and dynamic polarizabilities for the 6s21S0, 6s6p3P0o, and 6s6p3P1o states and estimate their uncertainties. A first-principles relativistic method is developed for an accurate calculation of the van der Waals coefficients of dimers involving excited-state atoms with strong decay channel to the ground state. This method is used for evaluation of the long-range interaction coefficients of particular experimental interest, including the C6 coefficients for the Yb-Yb 1S0+3P0,1o and 3P0o+3P0o dimers and C8 coefficients for the 1S0+1S0 and 1S0+3P1o dimers.

Porsev, S. G.; Safronova, M. S.; Derevianko, A.; Clark, Charles W.

2014-01-01

465

New ytterbium-doped apatite crystals for flexible laser design  

NASA Astrophysics Data System (ADS)

A new class of Yb-lasers is summarized in this article. The apatite family of crystals has been found to impose favorable spectroscopic and laser properties on the Yb(exp 3+) activator ion. Crystals of Yb-doped Ca5(PO4)(sub 3)F, Sr5(PO4)(sub 3)F, Ca(x)Sr(5-x)(PO4)(sub 3)F, and Sr5(VO4)(sub 3)F, have been grown and investigated. Several useful laser crystals have been identified which offer a variety of fundamental laser parameters for designing diode-pumped systems. In general, this class of materials is characterized by high emission cross sections 3.6-13.1 x 10(exp - 20) sq cm, useful emission lifetimes (0.59-1.26 msec), a strong pump band (sigma)(sub abs) = 2.0-10.0 x 10(exp -20) sq cm and pump and extraction wavelengths near 900 and 1,045 nm, respectively. Efficient lasing has been demonstrated for several of the members of this class of materials, and high optical quality crystals have been grown by the Czochralski method.

Payne, S. A.; Deloach, L. D.; Smith, L. K.; Krupke, W. F.; Chai, B. H. T.; Loutts, G.

1994-03-01

466

Intracavity optical trapping with Ytterbium doped fiber ring laser  

NASA Astrophysics Data System (ADS)

We propose a novel approach for trapping micron-sized particles and living cells based on optical feedback. This approach can be implemented at low numerical aperture (NA=0.5, 20X) and long working distance. In this configuration, an optical tweezers is constructed inside a ring cavity fiber laser and the optical feedback in the ring cavity is controlled by the light scattered from a trapped particle. In particular, once the particle is trapped, the laser operation, optical feedback and intracavity power are affected by the particle motion. We demonstrate that using this configuration is possible to stably hold micron-sized particles and single living cells in the focal spot of the laser beam. The calibration of the optical forces is achieved by tracking the Brownian motion of a trapped particle or cell and analysing its position distribution.

Sayed, Rania; Kalantarifard, Fatemeh; Elahi, Parviz; Ilday, F. Omer; Volpe, Giovanni; Maragò, Onofrio M.

2013-09-01

467

Modeling and measurement of ytterbium fiber laser generation spectrum  

NASA Astrophysics Data System (ADS)

A generation spectrum of a fiber laser becomes broader with increasing generation power. The spectra are rather narrow at low power and become comparable with fiber Bragg gratings (FBG) width at high power. It has been shown that the spectral broadening of a fiber laser can be described analytically if the generation spectrum is much narrower than the FBG width. The developed theory has been compared with experiment. Double clad Yb-doped fiber laser of up to 10 W output power is used in the experiment. Scanning Fabry-Perot interferometer with resolution down to 1.2 pm is applied for accurate spectral measurements. At power level less then 1 W a self-sustained pulsation regime accompanied by a narrow-line self-sweeping is observed. At higher power a quasi-CW generation regime with multiple longitudinal modes is established. Investigation of the regime shows linear increase of the generation width with generation power growth. Slope of the dependence has excellent agreement with the theory, but an additive quantity should be added to describe an absolute value that makes significant contribution at low powers. It has been shown that at low powers a spatial hole burning has to be considered. Theoretical model describing the hole burning effect for multimode cw generation is also developed. After inclusion of the hole burning effect the model starts to agree quantitatively with the linewidth measurements both at low and high powers.

Kablukov, Sergey I.; Zlobina, Ekaterina A.; Podivilov, Evgeniy V.; Babin, Sergey A.

2012-05-01

468

Synthesis and Photoluminescence of Ytterbium-doped Silicon Nanocrystals  

NASA Astrophysics Data System (ADS)

An innovative approach for binding Yb ions to the surface of Si nanocrystals (SiNC), based on the aptitude of Yb to form complexes with amino groups, was developed. SiNC produced by laser pyrolysis, with sizes ranging from 6 to 8 nm, were first functionalised with aminopropyltriethoxysilane (APTES) and then doped with Yb(III). The Yb-doped SiNC showed sharp PL (Photo-Luminescence) emission peaks at wavelengths around 1 ?m. Chemical reactions were performed by using different SiNC/Yb ratios, and it was found that the PL emission intensity increased as the amount of Yb increased.

D'Amato, Rosaria; Falconieri, Mauro; Borsella, Elisabetta

2010-10-01

469

Successive determination of praseodymium and ytterbium by coulometric complexometric titration  

Microsoft Academic Search

A method is described for the successive coulometric complexometric titration of microgram levels of light and heavy rare earth elements. The total amount of light and heavy rare earth elements is titrated by electrogenerating titrant EDTA on the mercury pool as a cathode. Then, the mercury pool is switched as an anode, electrogenerating Hg\\/sup 2 +\\/, and is used to

S. Chun-Nian; L. Jing-Ci; N. Qi-Dao; C. Mou-Sen

1982-01-01

470

Successive determination of praseodymium and ytterbium by coulometric complexometric titration  

SciTech Connect

A method is described for the successive coulometric complexometric titration of microgram levels of light and heavy rare earth elements. The total amount of light and heavy rare earth elements is titrated by electrogenerating titrant EDTA on the mercury pool as a cathode. Then, the mercury pool is switched as an anode, electrogenerating Hg/sup 2 +/, and is used to titrate EDTA which is displaced from its light rare earth elements complex by malic acid that has been added prior to the electrogenerating Hg/sup 2 +/. The heavy rare earth elements can be determined from the total rare earth elements minus the result of displacement titration of EDTA which is equivalent to the light rare earth elements. A 10-30 ..mu..g sample of light and heavy rare earth elements (Pr and Yb, La and Lu, Nd and Tm) can be determined successively. Errors and standard deviation are not more than 2.5% and 0.20, respectively. 2 tables, 5 figures.

Chun-Nian, S.; Jing-Ci, L.; Qi-Dao, N.; Mou-Sen, C.

1982-06-01

471

Ytterbium doped nanostructured optical fibers for high power fiber lasers  

Microsoft Academic Search

In this paper, we investigate Yb doped Y2O3 (or Y3Al6O12) nanoparticles in a silica rich matrix, as an alternative to the Yb in a 'standard', such as aluminium or phosphorous co-doped, silica host for use in high power fiber lasers. Y2O3 is a good host for RE incorporation, and efficient Yb:Y2O3 ceramic lasers have been reported. It is expected that

J. K. Sahu; M. C. Paul; M. P. Kalita; A. Boyland; C. Codemard; S. Yoo; A. Webb; R. J. Standish; J. Nilsson; S. Das; S. K. Bhadra; M. Pal; A. Dhar; R. Sen

2009-01-01

472

Topological crystalline Kondo insulator in mixed valence ytterbium borides.  

PubMed

The electronic structures of two mixed valence insulators YbB6 and YbB12 are studied by using the local density approximation supplemented with the Gutzwiller method and dynamic mean field theory. YbB6 is found to be a moderately correlated Z2 topological insulator, similar to SmB6 but having much larger bulk band gap. Notably, YbB12 is revealed to be in a new novel quantum state, strongly correlated topological crystalline Kondo insulator, which is characterized by its nonzero mirror Chern number. The surface calculations find an odd (three) and an even (four) number of Dirac cones for YbB6 and YbB12, respectively. PMID:24483913

Weng, Hongming; Zhao, Jianzhou; Wang, Zhijun; Fang, Zhong; Dai, Xi

2014-01-10

473

New ytterbium-doped apatite crystals for flexible laser design  

SciTech Connect

A new class of Yb-lasers is summarized in this article. The apatite family of crystals has been found to impose favorable spectroscopic and laser properties on the Yb{sup 3+} activator ion. Crystals of Yb-doped Ca{sub 5}(PO{sub 4}){sub 3}F, Sr{sub 5}(PO{sub 4}){sub 3}F, Ca{sub x}Sr{sub 5{minus}x}(PO{sub 4}){sub 3}F, and Sr{sub 5}(VO{sub 4}){sub 3}F have been grown and investigated. Several useful laser crystals have been identified which offer a variety of fundamental laser parameters for designing diode-pumped systems. In general, this class of materials is characterized by high emission cross sections (3.6--13.1 {times} 10{sup {minus}20} cm{sup 2}), useful emission lifetimes (0.59--1.26 msec), a strong pump band ({sigma}{sub abs} = 2.0--10.0 {times} 10{sup {minus}20} cm{sup 2}) and pump and extraction wavelengths near 900 and 1,045 nm, respectively. Efficient lasing has been demonstrated for several of the members of this class of materials, and high optical quality crystals have been grown by the Czochralski method.

Payne, S.A.; DeLoach, L.D.; Smith, L.K.; Krupke, W.F. [Lawrence Livermore National Lab., CA (United States); Chai, B.H.T.; Loutts, G. [Univ. of Central Florida, Orlando, FL (United States). Center for Research and Education in Optics and Lasers

1994-03-01

474

Nonlinear optical crystal optimized for Ytterbium laser host wavelengths  

DOEpatents

A material for harmonic generation has been made by substitutional changes to the crystal LaCa.sub.4 (BO.sub.3).sub.3 also known as LaCOB in the form Re1.sub.xRe2.sub.yRe3.sub.zCa.sub.4(B0.sub.3).sub.3O where Re1 and Re2, (rare earth ion 1 and rare earth ion 2) are selected from the group consisting of Sc, Yttrium, La, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, and Lu; Re3 is Lanthanum; and x+y+z=1.

Ebbers, Christopher A. (Pleasanton, CA) [Pleasanton, CA; Schaffers, Kathleen I. (Livermore, CA) [Livermore, CA

2008-05-27

475

Density-functional study of lanthanum, ytterbium, and lutetium dimers  

NASA Astrophysics Data System (ADS)

La2 , Yb2 , and Lu2 have been studied by use of the density-functional methods B3LYP, BLYP, B3PW91, BHLYP, BP86, B3P86, MPW1PW91, and PBE1PBE. In these density-functional methods, the exchange functional is from either Becke’s three-parameter HF-DFT hybrid exchange functional (B3), pure DFT exchange functional of 1988 (B), a modification of the half-and-half HF/DFT hybrid method (BH), Perdew-Wang 1991 (PW91), or Barone’s modified PW91 (MPW1), while the correlation functional is from either Lee, Yang, and Parr (LYP), Perdew-Wang 1991 (PW91), or Perdew 86 (P86). PBE1PBE is the generalized-gradient-approximation exchange-correlation functional of Perdew, Burke, and Ernzerhof. For La2 , the calculated bond distance is in reasonable agreement with the experiment, but the calculated vibrational frequency is underestimated significantly compared with the experiment. Only BP86 and B3P86 have the best performance in reproducing the experimental dissociation energy for La2 . For the van der Waals dimer Yb2 , three functionals, B3LYP, BLYP, and BHLYP have excellent performance in reproducing the spectroscopic constants compared with both the experiment and previous theoretical studies. For Lu2 , the overall performance of the density-functional methods is excellent in predicting the bond distance and vibrational frequency. While for the dissociation energy, PBE1PBE has excellent performance in reproducing the experimental value, followed by MPW1PW91 and B3P86.

Wu, Z. J.; Shi, J. S.; Zhang, S. Y.; Zhang, H. J.

2004-06-01

476

40 CFR 98.175 - Procedures for estimating missing data.  

Code of Federal Regulations, 2013 CFR

...procedures in § 98.255(b) of subpart Y (Petroleum Refineries) of this part for flares burning coke oven gas or blast furnace gas. You must document and keep records of the procedures used for all such estimates. (a) For each...

2013-07-01

477

14 CFR 25.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2010 CFR

...static longitudinal stability. Static longitudinal stability must be shown as follows...must have a stable slope at speeds between...Static longitudinal stability must be shown in the...must have a stable slope at all...

2009-01-01

478

14 CFR 25.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2010 CFR

...static longitudinal stability. Static longitudinal stability must be shown as follows...must have a stable slope at speeds between...Static longitudinal stability must be shown in the...must have a stable slope at all...

2010-01-01