1,142 research outputs found
Quantum anti-Zeno effect in artificial quantum systems
In this paper, we study a quantum anti-Zeno effect (QAZE) purely induced by
repetitive measurements for an artificial atom interacting with a structured
bath. This bath can be artificially realized with coupled resonators in one
dimension and possesses photonic band structure like Bloch electron in a
periodic potential. In the presence of repetitive measurements, the pure QAZE
is discovered as the observable decay is not negligible even for the atomic
energy level spacing outside of the energy band of the artificial bath. If
there were no measurements, the decay would not happen outside of the band. In
this sense, the enhanced decay is completely induced by measurements through
the relaxation channels provided by the bath. Besides, we also discuss the
controversial golden rule decay rates originated from the van Hove's
singularities and the effects of the counter-rotating terms.Comment: 12 pages, 8 figure
Aspisol inhibits tumor growth and induces apoptosis in breast cancer
Nonsteroidal anti-inflammatory drugs inhibit cell proliferation and induce apoptosis in various cancer cell lines, which is considered to be an important mechanism for their anti-tumor activity and cancer prevention. However, the molecular mechanisms through which these compounds induce apoptosis are not well understood. Aim: to determine the effects of nonselective cyclooxygenase-2 (COX-2) inhibitor, aspisol on breast cancer cells in vitro and in vivo. Methods: The cytotoxic activity of aspisol was evaluated by MTT assay. The apoptosis index of cells was measured by flow cytometry. Immunohistochemical staining was used to detect expressions of COX-2 and caspase-3 in MDA-MB-231 cells. The expression of bcl-2 and bax was analyzed by Western blot analysis. The content of prostaglandin E2 (PGE2) in MDA-MB-231 cells was estimated by ELISA. In vivo apoptosis of the tumor cells was detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). Results: Our results showed that aspisol reduced viability of MDA-MB-231 cells in time- and dose- dependent fashions and induced apoptosis by increase of caspase-3 and bax expressions while decrease of COX-2 and bcl-2 expression in vitro. In addition, exposure to aspisol decreased the basal release of PGE2. In vivo, aspisol also inhibited the proliferation of breast cancer cells and induced their apoptosis. Conclusions: Our in vitro and in vivo data indicated that the antitumor effects of aspisol on breast cancer cells was probably mediated by the induction of apoptosis, and it could be linked to the downregulation of the COX-2 or bcl-2 expression and up-regulation of caspase-3 or bax expression.ΠΠ΅ΡΡΠ΅ΡΠΎΠΈΠ΄Π½ΡΠ΅ ΠΏΡΠΎΡΠΈΠ²ΠΎΠ²ΠΎΡΠΏΠ°Π»ΠΈΡΠ΅Π»ΡΠ½ΡΠ΅ ΠΏΡΠ΅ΠΏΠ°ΡΠ°ΡΡ ΠΈΠ½Π³ΠΈΠ±ΠΈΡΡΡΡ ΠΏΡΠΎΠ»ΠΈΡΠ΅ΡΠ°ΡΠΈΡ ΠΊΠ»Π΅ΡΠΎΠΊ ΠΈ Π²ΡΠ·ΡΠ²Π°ΡΡ Π°ΠΏΠΎΠΏΡΠΎΠ· Π²ΠΎ ΠΌΠ½ΠΎΠ³ΠΈΡ
ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
ΠΊΠ»Π΅ΡΠΎΡΠ½ΡΡ
Π»ΠΈΠ½ΠΈΡΡ
, ΡΡΠΎ ΡΡΠΈΡΠ°Π΅ΡΡΡ Π²Π°ΠΆΠ½ΡΠΌ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΠΎΠΌ ΠΈΡ
ΠΏΡΠΎΡΠΈΠ²ΠΎΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΠΎΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΈ ΠΏΡΠΎΡΠΈΠ»Π°ΠΊΡΠΈΠΊΠΈ
ΡΠ°Π·Π²ΠΈΡΠΈΡ ΡΠ°ΠΊΠ°. Π’Π΅ΠΌ Π½Π΅ ΠΌΠ΅Π½Π΅Π΅ ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½ΡΠ΅ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΡ Π°ΠΏΠΎΠΏΡΠΎΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π΄Π΅ΠΉΡΡΠ²ΠΈΡ ΡΡΠΈΡ
ΠΏΡΠ΅ΠΏΠ°ΡΠ°ΡΠΎΠ² ΠΈΠ·ΡΡΠ΅Π½Ρ Π½Π΅Π΄ΠΎΡΡΠ°ΡΠΎΡΠ½ΠΎ.
Π¦Π΅Π»Ρ: ΠΈΠ·ΡΡΠΈΡΡ Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ Π½Π΅ΡΠΏΠ΅ΡΠΈΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΈΠ½Π³ΠΈΠ±ΠΈΡΠΎΡΠ° ΡΠΈΠΊΠ»ΠΎΠ³Π΅ΠΊΡΠΈΠ½Π°Π·Ρ-2 (COX-2) β Π°ΡΠΏΠΈΠ·ΠΎΠ»Π° β Π½Π° Π·Π»ΠΎΠΊΠ°ΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΠ΅ ΠΊΠ»Π΅ΡΠΊΠΈ
ΡΠ°ΠΊΠ° ΠΌΠΎΠ»ΠΎΡΠ½ΠΎΠΉ ΠΆΠ΅Π»Π΅Π·Ρ in vitro ΠΈ in vivo. ΠΠ΅ΡΠΎΠ΄Ρ: Π²ΡΠΆΠΈΠ²Π°Π΅ΠΌΠΎΡΡ ΠΊΠ»Π΅ΡΠΎΠΊ MDA-MB-231 ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΠ»ΠΈ Ρ ΠΏΠΎΠΌΠΎΡΡΡ MTT-ΡΠ΅ΡΡΠ°.
ΠΠΏΠΎΠΏΡΠΎΡΠΈΡΠ΅ΡΠΊΠΈΠΉ ΠΈΠ½Π΄Π΅ΠΊΡ ΠΈΠ·ΠΌΠ΅ΡΡΠ»ΠΈ Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΠΏΡΠΎΡΠΎΡΠ½ΠΎΠΉ ΡΠΈΡΠΎΠΌΠ΅ΡΡΠΈΠΈ ΠΈ ΠΈΠΌΠΌΡΠ½ΠΎΠ³ΠΈΡΡΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠΌ ΠΎΠΊΡΠ°ΡΠΈΠ²Π°Π½ΠΈΠ΅ΠΌ Ρ Π°Π½ΡΠΈΡΠ΅Π»Π°ΠΌΠΈ
ΠΏΡΠΎΡΠΈΠ² COX-2 ΠΈ ΠΊΠ°ΡΠΏΠ°Π·Ρ-3. ΠΠΊΡΠΏΡΠ΅ΡΡΠΈΡ bcl-2 ΠΈ bax ΠΈΠ·ΡΡΠ°Π»ΠΈ Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΠΠ΅ΡΡΠ΅ΡΠ½-Π±Π»ΠΎΡ-Π°Π½Π°Π»ΠΈΠ·Π°. Π‘ΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠ΅ ΠΏΡΠΎΡΡΠ°Π³Π»Π°Π½Π΄ΠΈΠ½Π°
E2
(PGE2
) Π² ΠΊΠ»Π΅ΡΠΊΠ°Ρ
MDA-MB-231 ΠΎΡΠ΅Π½ΠΈΠ²Π°Π»ΠΈ ΠΌΠ΅ΡΠΎΠ΄ΠΎΠΌ ELISA. In vivo Π°ΠΏΠΎΠΏΡΠΎΠ· ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΠ»ΠΈ
ΠΏΡΡΠ΅ΠΌ Π²ΡΡΠ²Π»Π΅Π½ΠΈΡ ΡΠ°Π·ΡΡΠ²ΠΎΠ² ΠΠΠ Ρ ΠΏΠΎΠΌΠΎΡΡΡ ΠΊΠΎΠ½ΡΠ΅Π²ΠΎΠΉ Π΄Π΅Π·ΠΎΠΊΡΠΈΠ½ΡΠΊΠ»Π΅ΠΎΡ-ΠΈΠ΄ΠΈΠ»ΡΡΠ°Π½ΡΠ΅ΡΠ°Π·Ρ (ΠΌΠ΅ΡΠΎΠ΄ TUNEL). Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ:
ΠΏΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ Π² Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ ΠΎΡ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ ΠΈΠ½ΠΊΡΠ±Π°ΡΠΈΠΈ ΠΈ Π΄ΠΎΠ·Ρ Π°ΡΠΏΠΈΠ·ΠΎΠ» ΡΠ³Π½Π΅ΡΠ°Π» ΡΠΎΡΡ ΠΊΠ»Π΅ΡΠΎΠΊ MDA-MB-231 in vitro ΠΈ Π²ΡΠ·ΡΠ²Π°Π»
ΠΈΡ
Π°ΠΏΠΎΠΏΡΠΎΠ· Π½Π° ΡΠΎΠ½Π΅ ΠΏΠΎΠ²ΡΡΠ΅Π½ΠΈΡ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ ΠΊΠ°ΡΠΏΠ°Π·Ρ-3 ΠΈ bax, Π° ΡΠ°ΠΊΠΆΠ΅ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΡ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ COX-2 ΠΈ bcl-2. Π ΡΡΠ»ΠΎΠ²ΠΈΡΡ
in vivo Π°ΡΠΏΠΈΠ·ΠΎΠ» ΡΠ°ΠΊΠΆΠ΅ ΠΈΠ½Π³ΠΈΠ±ΠΈΡΠΎΠ²Π°Π» ΠΏΡΠΎΠ»ΠΈΡΠ΅ΡΠ°ΡΠΈΡ Π·Π»ΠΎΠΊΠ°ΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΡ
ΠΊΠ»Π΅ΡΠΎΠΊ ΡΠ°ΠΊΠ° ΠΌΠΎΠ»ΠΎΡΠ½ΠΎΠΉ ΠΆΠ΅Π»Π΅Π·Ρ ΠΈ Π²ΡΠ·ΡΠ²Π°Π» ΠΈΡ
Π°ΠΏΠΎΠΏΡΠΎΠ·.
ΠΡΠ²ΠΎΠ΄Ρ: Π΄Π°Π½Π½ΡΠ΅, ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΠ΅ in vitro ΠΈ in vivo, ΡΠ²ΠΈΠ΄Π΅ΡΠ΅Π»ΡΡΡΠ²ΡΡΡ ΠΎ ΠΏΡΠΎΡΠΈΠ²ΠΎΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΠΎΠΌ ΡΡΡΠ΅ΠΊΡΠ΅ Π°ΡΠΏΠΈΠ·ΠΎΠ»Π° Π½Π° ΠΊΠ»Π΅ΡΠΊΠΈ ΡΠ°ΠΊΠ°
ΠΌΠΎΠ»ΠΎΡΠ½ΠΎΠΉ ΠΆΠ΅Π»Π΅Π·Ρ, ΡΡΠΎ ΡΠΊΠΎΡΠ΅Π΅ Π²ΡΠ΅Π³ΠΎ ΠΎΠΏΠΎΡΡΠ΅Π΄ΠΎΠ²Π°Π½ΠΎ Π΅Π³ΠΎ ΠΏΡΠΎΠ°ΠΏΠΎΠΏΡΠΎΡΠΈΡΠ΅ΡΠΊΠΈΠΌ Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ΠΌ ΠΈ ΠΌΠΎΠΆΠ΅Ρ Π±ΡΡΡ ΡΠ²ΡΠ·Π°Π½ΠΎ ΡΠΎ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΠ΅ΠΌ
ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ COX-2 ΠΈ bcl-2, Π° ΡΠ°ΠΊΠΆΠ΅ ΠΏΠΎΠ²ΡΡΠ΅Π½ΠΈΠ΅ΠΌ ΡΠΊΡΠΏΡΠ΅ΡΡΠΈΠΈ ΠΊΠ°ΡΠΏΠ°Π·Ρ-3 ΠΈ bax
Dynamics of quantum entanglement in the reservoir with memory effects
The non-Markovian dynamics of quantum entanglement is studied by the
Shabani-Lidar master equation when one of entangled quantum systems is coupled
to a local reservoir with memory effects. The completely positive reduced
dynamical map can be constructed in the Kraus representation. Quantum
entanglement decays more slowly in the non-Markovian environment. The
decoherence time for quantum entanglement can be markedly increased by the
change of the memory kernel. It is found out that the entanglement sudden death
between quantum systems and entanglement sudden birth between the system and
reservoir occur at different instants.Comment: 14 pages, 3 figure
Candidates for membrane progestin receptors: past approaches and future challenges
Progestins have a broad range of functions in reproductive biology. Many rapid nongenomic actions of progestins have been identified, including induction of oocyte maturation, modulation of reproductive signaling in the brain, rapid activation of breast cancer cell signaling, induction of the acrosomal reaction and hypermotility in mammalian sperm. Currently, there are three receptor candidates for mediating rapid progestin actions: (1) membrane progestin receptors (mPRs); (2) progestin receptor membrane components (PGRMCs); and (3) nuclear progestin receptors (nPRs). The recently-described mPR family of proteins has seven integral transmembrane domains and mediates signaling via G-protein coupled pathways. The PGRMCs have a single transmembrane with putative Src homology domains for potential activation of second messengers. The classical nPRs, in addition to having well defined transcriptional activity, can also mediate rapid activation of intracellular signaling pathways. However, details of the mechanisms by which these three classes of progestin receptors mediate rapid intracellular signaling and their subcellular localization remain unclear. In addition, mPRs, nPRs and PGRMCs exhibit overlapping expression and functions in multiple tissues, implying potential interactions during oocyte maturation, parturition, and breast cancer signaling in individual cells. However, the overwhelming majority of studies to date have focused on the functions of one of these groups of receptors in isolation. This review will summarize recent findings on the three major progestin receptor candidates, emphasizing the different approaches used, some experimental pitfalls, and current controversies. We will also review evidence for the involvement of mPRs and nPRs in one of the most well-characterized nongenomic steroid actions in basal vertebrates, oocyte maturation, and conclude by suggesting some future areas of research. Clarification of the controversies surrounding the identities and localization of membrane progestin receptors may help direct future research that could advance our understanding of rapid actions of steroids.Animal science
Hadronic Parity Violation and Inelastic Electron-Deuteron Scattering
We compute contributions to the parity-violating (PV) inelastic
electron-deuteron scattering asymmetry arising from hadronic PV. While hadronic
PV effects can be relatively important in PV threshold electro- disintegration,
we find that they are highly suppressed at quasielastic kinematics. The
interpretation of the PV quasielastic asymmetry is, thus, largely unaffected by
hadronic PV.Comment: 27 pages, 13 figures, uses REVTeX and BibTe
Search for the Rare Decays J/Psi --> Ds- e+ nu_e, J/Psi --> D- e+ nu_e, and J/Psi --> D0bar e+ e-
We report on a search for the decays J/Psi --> Ds- e+ nu_e + c.c., J/Psi -->
D- e+ nu_e + c.c., and J/Psi --> D0bar e+ e- + c.c. in a sample of 5.8 * 10^7
J/Psi events collected with the BESII detector at the BEPC. No excess of signal
above background is observed, and 90% confidence level upper limits on the
branching fractions are set: B(J/Psi --> Ds- e+ nu_e + c.c.)<4.8*10^-5, B(J/Psi
--> D- e+ nu_e + c.c.) D0bar e+ e- + c.c.)<1.1*10^-5Comment: 10 pages, 4 figure
Pulsar Timing and its Application for Navigation and Gravitational Wave Detection
Pulsars are natural cosmic clocks. On long timescales they rival the
precision of terrestrial atomic clocks. Using a technique called pulsar timing,
the exact measurement of pulse arrival times allows a number of applications,
ranging from testing theories of gravity to detecting gravitational waves. Also
an external reference system suitable for autonomous space navigation can be
defined by pulsars, using them as natural navigation beacons, not unlike the
use of GPS satellites for navigation on Earth. By comparing pulse arrival times
measured on-board a spacecraft with predicted pulse arrivals at a reference
location (e.g. the solar system barycenter), the spacecraft position can be
determined autonomously and with high accuracy everywhere in the solar system
and beyond. We describe the unique properties of pulsars that suggest that such
a navigation system will certainly have its application in future astronautics.
We also describe the on-going experiments to use the clock-like nature of
pulsars to "construct" a galactic-sized gravitational wave detector for
low-frequency (f_GW ~1E-9 - 1E-7 Hz) gravitational waves. We present the
current status and provide an outlook for the future.Comment: 30 pages, 9 figures. To appear in Vol 63: High Performance Clocks,
Springer Space Science Review
Study of J/psi decays to Lambda Lambdabar and Sigma0 Sigma0bar
The branching ratios and Angular distributions for J/psi decays to Lambda
Lambdabar and Sigma0 Sigma0bar are measured using BESII 58 million J/psi.Comment: 11 pages, 5 figure
Direct Measurements of the Branching Fractions for and and Determinations of the Form Factors and
The absolute branching fractions for the decays and
are determined using singly
tagged sample from the data collected around 3.773 GeV with the
BES-II detector at the BEPC. In the system recoiling against the singly tagged
meson, events for and events for decays are observed. Those yield
the absolute branching fractions to be and . The
vector form factors are determined to be
and . The ratio of the two form
factors is measured to be .Comment: 6 pages, 5 figure
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