1,733 research outputs found
Expression of anion exchanger 2 in human gastric cancer
Anion exchanger 2 (AE2), which mediates exchange of Cl-/HCO3- across the plasma membrane, is widely expressed in body tissues. It is most abundantly expressed in stomach and is responsible for the uptake of Cl- ions that are destined to become HCl molecules. Aim: To determine whether AE2 expression was altered in gastric tumors. Methods: We have studied AE2 expression in normal human gastric tissues (n =16) and in gastric tumors (n = 33) using immunohistochemistry and immunofluorescent labeling. Results: In normal gastric tissue positive staining was observed in gastric fundus gland, suggesting parietal cell-related expression of AE2, and AE2 expression was localized in the nuclear membrane and even in cell nuclei. For assay of cancerous gastric tissues, specimens of human gastric cancer arising from the region of the fundus (2 cases), the body (14 cases) and the antrum (17 cases) were randomly selected. Immunohistochemical staining has showed that AE2 was down-regulated in all 14 cancerous gastric body specimens, whereas staining for AE2 in cancerous antrum was less intense and had a diffuse profile. Conclusions: The data suggest that AE2 might be associated with gastric carcinogenesis and the achlorhydria experienced by gastric cancer patients.ΠΠ½ΠΈΠΎΠ½Π½ΡΠΉ ΠΎΠ±ΠΌΠ΅Π½Π½ΠΈΠΊ 2 (ΠΠ2), ΠΊΠΎΡΠΎΡΡΠΉ ΠΎΠΏΠΎΡΡΠ΅Π΄ΡΠ΅Ρ ΠΏΠ΅ΡΠ΅Π½ΠΎΡ Cl-
/HCO3
-
ΡΠ΅ΡΠ΅Π· ΠΏΠ»Π°Π·ΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΡΡ ΠΌΠ΅ΠΌΠ±ΡΠ°Π½Ρ, ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΡΡΠ΅ΡΡΡ
ΠΊΠ»Π΅ΡΠΊΠ°ΠΌΠΈ ΡΠ°Π·Π½ΡΡ
ΡΠΊΠ°Π½Π΅ΠΉ. Π‘Π°ΠΌΡΠΉ Π²ΡΡΠΎΠΊΠΈΠΉ ΡΡΠΎΠ²Π΅Π½Ρ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ ΠΠ2 Π² ΠΆΠ΅Π»ΡΠ΄ΠΊΠ΅, ΠΏΠΎΡΠΊΠΎΠ»ΡΠΊΡ ΡΡΠΎΡ Π±Π΅Π»ΠΎΠΊ ΠΎΡΠ²Π΅ΡΠ°Π΅Ρ Π·Π° ΠΏΠΎΠ³Π»ΠΎΡΠ΅Π½ΠΈΠ΅
ΠΈΠΎΠ½ΠΎΠ² Cl-
, ΠΊΠΎΡΠΎΡΡΠ΅ Π²ΠΏΠΎΡΠ»Π΅Π΄ΡΡΠ²ΠΈΠΈ ΠΈΡΠΏΠΎΠ»ΡΠ·ΡΡΡΡΡ Π΄Π»Ρ ΡΠ΅ΠΊΡΠ΅ΡΠΈΠΈ HCl. Π¦Π΅Π»Ρ: ΠΠ·ΡΡΠΈΡΡ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡ Π² ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ ΠΠ2 ΠΏΡΠΈ ΡΠ°ΠΊΠ΅
ΠΆΠ΅Π»ΡΠ΄ΠΊΠ°. ΠΠ΅ΡΠΎΠ΄Ρ: ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½Π° ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΡ ΠΠ2 Π² Π½ΠΎΡΠΌΠ°Π»ΡΠ½ΡΡ
ΡΠΊΠ°Π½ΡΡ
(n = 16) ΠΈ ΠΎΠΏΡΡ
ΠΎΠ»ΡΡ
ΠΆΠ΅Π»ΡΠ΄ΠΊΠ° (n = 33) Ρ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ΠΌ
ΠΌΠ΅ΡΠΎΠ΄ΠΎΠ² ΠΈΠΌΠΌΡΠ½ΠΎΠ³ΠΈΡΡΠΎΡ
ΠΈΠΌΠΈΠΈ ΠΈ ΠΈΠΌΠΌΡΠ½ΠΎΡΠ»ΡΠΎΡΠ΅ΡΡΠ΅Π½ΡΠΈΠΈ. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ: Π² Π½Π΅ΡΡΠ°Π½ΡΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠΉ ΡΠΊΠ°Π½ΠΈ ΠΆΠ΅Π»ΡΠ΄ΠΊΠ° Π² ΡΡΠ½Π΄Π°Π»ΡΠ½ΠΎΠΉ
ΠΆΠ΅Π»Π΅Π·Π΅ Π²ΡΡΠ²Π»ΡΠ»ΠΈ ΡΠΈΠ»ΡΠ½ΡΡ ΠΏΠΎΠ»ΠΎΠΆΠΈΡΠ΅Π»ΡΠ½ΡΡ ΡΠ΅Π°ΠΊΡΠΈΡ, ΡΡΠΎ ΡΠ²ΠΈΠ΄Π΅ΡΠ΅Π»ΡΡΡΠ²ΡΠ΅Ρ ΠΎΠ± ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ ΠΠ2 ΠΏΠ°ΡΠΈΠ΅ΡΠ°Π»ΡΠ½ΡΠΌΠΈ ΠΊΠ»Π΅ΡΠΊΠ°ΠΌΠΈ,
ΠΏΡΠΈΡΠ΅ΠΌ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΡ ΠΠ2 Π±ΡΠ»Π° Π»ΠΎΠΊΠ°Π»ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π° Π² ΡΠ΄Π΅ΡΠ½ΠΎΠΉ ΠΌΠ΅ΠΌΠ±ΡΠ°Π½Π΅ ΠΈ Π² ΡΠ΄ΡΠ΅. Π ΠΎΠΏΡΡ
ΠΎΠ»ΡΡ
ΠΆΠ΅Π»ΡΠ΄ΠΊΠ° (ΡΡΠ½Π΄Π°Π»ΡΠ½ΠΎΠ³ΠΎ ΠΎΡΠ΄Π΅Π»Π° (n =
2), ΡΠ΅Π»Π° (n = 14) ΠΈ Π°Π½ΡΡΠ°Π»ΡΠ½ΠΎΠ³ΠΎ ΠΎΡΠ΄Π΅Π»Π° (n = 17)), ΠΎΡΠΎΠ±ΡΠ°Π½Π½ΡΡ
ΡΠ»ΡΡΠ°ΠΉΠ½ΡΠΌ ΠΎΠ±ΡΠ°Π·ΠΎΠΌ, Π±ΡΠ» ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ Π°Π½Π°Π»ΠΈΠ· ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ ΠΠ2.
ΠΠΌΠΌΡΠ½ΠΎΠ³ΠΈΡΡΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΎ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΠ΅ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ ΠΠ2 Π²ΠΎ Π²ΡΠ΅Ρ
14 ΡΠ»ΡΡΠ°ΡΡ
ΡΠ°ΠΊΠ° ΡΠ΅Π»Π° ΠΆΠ΅Π»ΡΠ΄ΠΊΠ°. ΠΠΊΡΠ°ΡΠΈΠ²Π°Π½ΠΈΠ΅
ΠΠ2 Π² ΠΎΠ±ΡΠ°Π·ΡΠ°Ρ
ΡΠ°ΠΊΠ° Π°Π½ΡΡΠ°Π»ΡΠ½ΠΎΠ³ΠΎ ΠΎΡΠ΄Π΅Π»Π° ΠΆΠ΅Π»ΡΠ΄ΠΊΠ° Π±ΡΠ»ΠΎ ΠΌΠ΅Π½Π΅Π΅ ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΡΠΌ ΠΈ Π΄ΠΈΡΡΡΠ·Π½ΡΠΌ. ΠΡΠ²ΠΎΠ΄Ρ: ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΠ΅
Π΄Π°Π½Π½ΡΠ΅ ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡΡ ΠΏΡΠ΅Π΄ΠΏΠΎΠ»ΠΎΠΆΠΈΡΡ Π½Π°Π»ΠΈΡΠΈΠ΅ ΡΠ²ΡΠ·ΠΈ ΠΌΠ΅ΠΆΠ΄Ρ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠ΅ΠΉ ΠΠ2 ΠΈ ΡΠ°Π·Π²ΠΈΡΠΈΠ΅ΠΌ ΡΠ°ΠΊΠ° ΠΆΠ΅Π»ΡΠ΄ΠΊΠ°, Π° ΡΠ°ΠΊΠΆΠ΅ Π°Ρ
Π»ΠΎΡΠ³ΠΈΠ΄ΡΠΈΠ΅ΠΉ,
ΠΎΡΠΌΠ΅ΡΠ°Π΅ΠΌΠΎΠΉ Ρ Π±ΠΎΠ»ΡΠ½ΡΡ
ΡΠ°ΠΊΠΎΠΌ ΠΆΠ΅Π»ΡΠ΄ΠΊΠ°
Complex-valued Burgers and KdV-Burgers equations
Spatially periodic complex-valued solutions of the Burgers and KdV-Burgers
equations are studied in this paper. It is shown that for any sufficiently
large time T, there exists an explicit initial data such that its corresponding
solution of the Burgers equation blows up at T. In addition, the global
convergence and regularity of series solutions is established for initial data
satisfying mild conditions
A Superstabilizing -Approximation Algorithm for Dynamic Steiner Trees
In this paper we design and prove correct a fully dynamic distributed
algorithm for maintaining an approximate Steiner tree that connects via a
minimum-weight spanning tree a subset of nodes of a network (referred as
Steiner members or Steiner group) . Steiner trees are good candidates to
efficiently implement communication primitives such as publish/subscribe or
multicast, essential building blocks for the new emergent networks (e.g. P2P,
sensor or adhoc networks). The cost of the solution returned by our algorithm
is at most times the cost of an optimal solution, where is the
group of members. Our algorithm improves over existing solutions in several
ways. First, it tolerates the dynamism of both the group members and the
network. Next, our algorithm is self-stabilizing, that is, it copes with nodes
memory corruption. Last but not least, our algorithm is
\emph{superstabilizing}. That is, while converging to a correct configuration
(i.e., a Steiner tree) after a modification of the network, it keeps offering
the Steiner tree service during the stabilization time to all members that have
not been affected by this modification
Techniques of replica symmetry breaking and the storage problem of the McCulloch-Pitts neuron
In this article the framework for Parisi's spontaneous replica symmetry
breaking is reviewed, and subsequently applied to the example of the
statistical mechanical description of the storage properties of a
McCulloch-Pitts neuron. The technical details are reviewed extensively, with
regard to the wide range of systems where the method may be applied. Parisi's
partial differential equation and related differential equations are discussed,
and a Green function technique introduced for the calculation of replica
averages, the key to determining the averages of physical quantities. The
ensuing graph rules involve only tree graphs, as appropriate for a
mean-field-like model. The lowest order Ward-Takahashi identity is recovered
analytically and is shown to lead to the Goldstone modes in continuous replica
symmetry breaking phases. The need for a replica symmetry breaking theory in
the storage problem of the neuron has arisen due to the thermodynamical
instability of formerly given solutions. Variational forms for the neuron's
free energy are derived in terms of the order parameter function x(q), for
different prior distribution of synapses. Analytically in the high temperature
limit and numerically in generic cases various phases are identified, among
them one similar to the Parisi phase in the Sherrington-Kirkpatrick model.
Extensive quantities like the error per pattern change slightly with respect to
the known unstable solutions, but there is a significant difference in the
distribution of non-extensive quantities like the synaptic overlaps and the
pattern storage stability parameter. A simulation result is also reviewed and
compared to the prediction of the theory.Comment: 103 Latex pages (with REVTeX 3.0), including 15 figures (ps, epsi,
eepic), accepted for Physics Report
Geochronological and geochemical constraints on Late Cryogenian to Early Ediacaran magmatic rocks on the northern Tarim Craton:implications for tectonic setting and affinity with Gondwana
The Tarim Craton provides a geologic record of both the fragmentation of the Rodinian supercontinent and the subsequent assembly of Gondwana. However, the timing and interactions of these radically different tectonic processes remain contested. A critical part of this debate revolves around the Late Cryogenian-Ediacaran igneous rocks along the Cratonβs northern margin, specifically, whether they record super-plume related Rodinian breakup or Gondwanan orogeny. To address this issue, we present zircon U-Pb-Hf isotopic data and whole rock geochemistry from Late Cryogenian to Early Ediacaran granitoids of the northern Tarim Craton. U-Pb zircon ages reveal three magmatic periods along the northern Tarim margin: ca. 660β640 Ma, 635β625 Ma and 620β600 Ma, associated with small scale felsic and mafic magmas. These granitoids have an A2-type affinity and are enriched in alkalines, but are depleted in Nb, Ta, Sr, P and Ti. Elemental data and generally negative Ξ΅Hf(t) values (β13.96 to 1.65) suggest that they were mainly derived from partial melting of enriched, subduction-modified lithospheric mantle triggered by upwelling of the asthenospheric mantle along the active continental margin of northern Tarim. We suggest that the Tarim Craton travelled as an isolated plate for much of the Late Neoproterozoic, near the outer part of Rodinia and subsequently Gondwana. During this time it was affected by localized and periodic subduction-related intrusion and eruption. However, within the samples of this study, there is no U-Pb-Hf isotopic and whole-rock geochemical evidence to support either super-plume-related rifting (i.e. Rodinian breakup) or Pan-African orogeny (i.e. Gondwanan assembly).</p
Exact Results on Potts Model Partition Functions in a Generalized External Field and Weighted-Set Graph Colorings
We present exact results on the partition function of the -state Potts
model on various families of graphs in a generalized external magnetic
field that favors or disfavors spin values in a subset of
the total set of possible spin values, , where and are
temperature- and field-dependent Boltzmann variables. We remark on differences
in thermodynamic behavior between our model with a generalized external
magnetic field and the Potts model with a conventional magnetic field that
favors or disfavors a single spin value. Exact results are also given for the
interesting special case of the zero-temperature Potts antiferromagnet,
corresponding to a set-weighted chromatic polynomial that counts
the number of colorings of the vertices of subject to the condition that
colors of adjacent vertices are different, with a weighting that favors or
disfavors colors in the interval . We derive powerful new upper and lower
bounds on for the ferromagnetic case in terms of zero-field
Potts partition functions with certain transformed arguments. We also prove
general inequalities for on different families of tree graphs.
As part of our analysis, we elucidate how the field-dependent Potts partition
function and weighted-set chromatic polynomial distinguish, respectively,
between Tutte-equivalent and chromatically equivalent pairs of graphs.Comment: 39 pages, 1 figur
Spin-Peierls phases in pyrochlore antiferromagnets
In the highly frustrated pyrochlore magnet spins form a lattice of corner
sharing tetrahedra. We show that the tetrahedral ``molecule'' at the heart of
this structure undergoes a Jahn-Teller distortion when lattice motion is
coupled to the antiferromagnetism. We extend this analysis to the full
pyrochlore lattice by means of Landau theory and argue that it should exhibit
spin-Peierls phases with bond order but no spin order. We find a range of Neel
phases, with collinear, coplanar and noncoplanar order. While collinear Neel
phases are easiest to generate microscopically, we also exhibit an interaction
that gives rise to a coplanar state instead.Comment: REVTeX 4, 14 pages, 12 figures (best viewed in color
Coexistence of ferro- and antiferromagnetic order in Mn-doped NiMnGa
Ni-Mn-Ga is interesting as a prototype of a magnetic shape-memory alloy
showing large magnetic field induced strains. We present here results for the
magnetic ordering of Mn-rich Ni-Mn-Ga alloys based on both experiments and
theory. Experimental trends for the composition dependence of the magnetization
are measured by a vibrating sample magnetometer (VSM) in magnetic fields of up
to several tesla and at low temperatures. The saturation magnetization has a
maximum near the stoichiometric composition and it decreases with increasing Mn
content. This unexpected behaviour is interpreted via first-principles
calculations within the density-functional theory. We show that extra Mn atoms
are antiferromagnetically aligned to the other moments, which explains the
dependence of the magnetization on composition. In addition, the effect of Mn
doping on the stabilization of the structural phases and on the magnetic
anisotropy energy is demonstrated.Comment: 4 pages, 3 figure
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