1,798 research outputs found
Real-time quantitative RT-PCR identifies distinct c-RET, RET/PTC1 and RET/PTC3 expression patterns in papillary thyroid carcinoma
No full textRET/PTC1 and RET/PTC3 are the markers for papillary thyroid carcinoma. Their reported prevalence varies broadly. Nonrearranged c-RET has also been detected in a variable proportion of papillary carcinomas. The published data suggest that a wide range in expression levels may contribute to the different frequency of c-RET and, particularly, of RET/PTC detection. However, quantitative expression analysis has never been systematically carried out. We have analyzed by real-time RT-PCR 25 papillary carcinoma and 12 normal thyroid samples for RET/PTC1, RET/PTC3 and for RET exons 10-11 and 12-13, which are adjacent to the rearrangement site. The variability in mRNA levels was marked and four carcinoma groups were identified: one lacking RET/ PTC rearrangement with balanced RET exon levels similar to those of the normal samples (7/25 cases, 28%), the second (6/25 cases, 24%) with balanced RET expression and very low levels of RET/PTC1, the third with unbalanced RET exons 10-11 and 12-13 expression, high RET/PTC1 levels but no RET/PTC3 (7/25 cases, 28%), and the fourth with unbalanced RET expression, high RET/PTC1 levels and low levels of RET/PTC3 (5/25 cases, 20%). Papillary carcinomas with high RET/PTC1 expression showed an association trend for large tumor size (P=0.063). Our results indicate that the variability in c-RET and RET/PTC mRNA levels contributes to the apparent inconsistencies in their reported detection rates and should be taken into account not only for diagnostic purposes but also to better understand the role of c-RET activation in thyroid tumorigenesi
Invariant tori and Lagrange stability of pendulum-type equations
No full textAbstractIn this paper we prove that the pendulum-type equation x″ + g(t, x) = 0 possesses infinitely many invariant tori whenever g(t, x) has zero mean value on the torus T2, where g(t, x) belongs to C∞(T2). This yields the boundedness for solutions of the considered pendulum-type equation and thus leads to an answer to J. Moser's boundedness problem (1973, Ann. of Math. Stud. 77)
The charged and the spin-excitation gaps in the double-exchange model: a rigorous result
No full textWe extend a previous result of ours [G.S. Tian, Phys. Rev. B58 (1998) 7612] on the charged gap and the spin-excitation gap of the half-filled Kondo lattice model to the double-exchange model. In our original approach, this model cannot be dealt with since its localized spins have a large spin number S = 3/2. By following a construction argument due to Zener and rewriting the double-exchange Hamiltonian, we are able to overcome this difficulty and re-establish the same relation for this model.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000088659700004&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)3ARTICLE121-303
A 2-watt balanced power amplifier MMIC for Ku-band satellite communications
No full textA Ku-band power amplifier MMIC has been developed using 0.25-mum GaAs pHEMT technology. To achieve small chip size and simple drain-bias connection, a bus-bar power combiner is used. Also, balanced-power amplifier topology is used to obtain good input/ output return losses. The small-signal gain is about 15 dB and the gain variation is less than 1 dB from 12 to 17 GHz. Good input/output return losses are achieved at less than -15 dB due to the balanced topology. P-IdB of 32.6 dBm and PAE of 23.5% are achieved at 14 GHz. The effective chip area is 4.2 X 3.2 mm. Because the power amplifier is implemented using the balanced topology with the bus-bar power combiner, compact size, high output power, and good input/output return losses can be achieved simultaneously. (C) 2004 Wiley Periodicals, Inc.The author would like to thank Jeong-Ho Lee, Chung-Hwan Kim,
and Jae-Jin Lee at Teltron for their helpful discussions and encouragement.
This work was supported by KOSEF under the ERC
program through the MINT research center at Dongguk University
Flexicurity - Useful Oxymoron or Genuine Class Compromise?
No full textAuthor has checked copyrightDG 16/11/12Names JG 2012-11-1
Alexander Type Invariants of Tangles, Skew Howe Duality for Crystals and The Cactus Group
No full textThis thesis consists of two parts, the first part is in the setting of algebraic knot theory while the second studies ideas in representation theory.
In the first part of this work, we study generalizations of a classical link invariant--the multivariable Alexander polynomial--to tangles. The starting point is Archibald's tMVA invariant for virtual tangles which lives in the setting of circuit algebras. Using the Hodge star map and restricting to tangles without closed components, we define a reduction of the tMVA to an invariant (rMVA) which is valued in matrices with entries equal to certain Laurent polynomials. We show the rMVA has the structure of a metamonoid morphism and is further equivalent to a tangle invariant defined by Bar-Natan. This invariant also reduces to the Gassner representation on braids and has a partially defined trace operation for closing open strands of a tangle.
In the second part, we look at crystals and the cactus group. The crystals for a finite-dimensional complex reductive Lie algebra g encode the structure of its representations, yet can also reveal surprising new structure of their own. In this work, we construct a group J g, the "cactus group'', using the Dynkin diagram of g and show that it acts combinatorially on any g-crystal via the Schützenberger involutions. Henriques and Kamnitzer studied Jn = Jg ln, and constructed an action of it on n-tensor products of g-crystals, for any g as above. We discuss the crystal corresponding to the gln × glm-representation Λ N(Cn ⊗ Cm), derive skew Howe duality on the crystal level and show that the two cactus group actions agree in this setting. An application of this result is discussed in studying a family of maximal commutative subalgebras of the universal enveloping algebra, the shift of argument and Gaudin algebras, where an algebraically constructed monodromy action is expected to match that of the cactus group.Ph.D
Gesetzliche Mindestlöhne in Irland
No full textAuthor has checked copyrightDG 16/11/12Names JG 2012-11-1
The Dirichlet Problem for the Degenerate Elliptic Monge–Ampère Equation
No full textAbstractThe existence and uniqueness of the global C1,1/3 solution to the Dirichlet problem for the degenerate elliptic Monge–Ampère equation are proved, under mild conditions, and the application to the equation of the prescribed nonnegative Gauss curvature is also given
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