203 research outputs found
Fictitious Magnetic Resonance by Quasi-Electrostatic Field
We propose a new kind of spin manipulation method using a {\it fictitious}
magnetic field generated by a quasi-electrostatic field. The method can be
applicable to every atom with electron spins and has distinct advantages of
small photon scattering rate and local addressability. By using a
laser as a quasi-electrostatic field, we have experimentally demonstrated the
proposed method by observing the Rabi-oscillation of the ground state hyperfine
spin F=1 of the cold atoms and the Bose-Einstein condensate.Comment: 5 pages, 5 figure
Inhibitory Effects of Anti-VEGF Antibody on the Growth and Angiogenesis of Estrogen-induced Pituitary Prolactinoma in Fischer 344 Rats: Animal Model of VEGF-targeted Therapy for Human Endocrine Tumors
Estrogen-induced pituitary prolactin-producing tumors (PRLoma) in F344 rats express a high level of vascular endothelial growth factor (VEGF) associated with marked angiogenesis and angiectasis. To investigate whether tumor development in E2-induced PRLoma is inhibited by anti-VEGF monoclonal antibody (G6-31), we evaluated tumor growth and observed the vascular structures. With simultaneous treatment with G6-31 for the latter three weeks of the 13-week period of E2 stimulation (E2+G6-31 group), the following inhibitory effects on the PRLoma were observed in the E2+G6-31 group as compared with the E2-only group. In the E2+G6-31 group, a tendency to reduction in pituitary weight was observed and significant differences were observed as (1) reductions in the Ki-67-positive anterior cells, (2) increases in TUNEL-positive anterior cells, and (3) repair of the microvessel count by CD34-immunohistochemistry. The characteristic âblood lakesâ in PRLomas were improved and replaced by repaired microvascular structures on 3D observation using confocal laser scanning microscope. These inhibitory effects due to anti-VEGF antibody might be related to the autocrine/paracrine action of VEGF on the tumor cells, because VEGF and its receptor are co-expressed on the tumor cells. Thus, our results demonstrate that anti-VEGF antibody exerted inhibitory effects on pituitary tumorigenesis in well-established E2 induced PRLomas
Pathology, Pathogenesis and Therapy of Growth Hormone (GH)-producing Pituitary Adenomas: Technical Advances in Histochemistry and Their Contribution
Growth hormone (GH)-producing adenomas (GHomas) are one of the most frequently-occurring pituitary adenomas. Differentiation of hormone-producing cells in the pituitary gland is regulated by transcription factors and co-factors. The transcription factors include Pit-1, Prop-1, NeuroD1, Tpit, GATA-2, SF-1. Aberrant expression of transcription factors such as Pit-1 results in translineage expression of GH in adrenocorticotropic hormone-producing adenomas (ACTHomas). This situation has been substantiated by GFP-Pit-1 transfection expression in the AtT20 cell line. Experimentally, GHomas have been induced in GH-releasing hormone (GHRH) or Prop-1 transgenic animals. Immunohistochemical detection of somatostatin receptor (SSTR2a) has recently emphasized their role in the response of GHomas to somatostatin analogue therapy. In this review, the advances in technology and their contribution to cell biology and medical practice are discussed
Molecular Dynamics Simulation of Sympathetic Crystallization of Molecular Ions
It is shown that the translational degrees of freedom of a large variety of
molecules, from light diatomic to heavy organic ones, can be cooled
sympathetically and brought to rest (crystallized) in a linear Paul trap. The
method relies on endowing the molecules with an appropriate positive charge,
storage in a linear radiofrequency trap, and sympathetic cooling. Two
well--known atomic coolant species, and
, are sufficient for cooling the molecular mass range
from 2 to 20,000 amu. The large molecular charge required for simultaneous
trapping of heavy molecules and of the coolant ions can easily be produced
using electrospray ionization. Crystallized molecular ions offer vast
opportunities for novel studies.Comment: Accepted for publication in Phys. Rev.
Intermittent maser flare around the high mass young stellar object G353.273+0.641 I: data & overview
We have performed VLBI and single-dish monitoring of 22 GHz HO maser
emission from the high mass young stellar object G353.273+0.641 with VERA (VLBI
Exploration of Radio Astrometry) and Tomakamai 11-m radio telescope. Two maser
flares have been detected, separated almost two years. Frequent VLBI monitoring
has revealed that these flare activities have been accompanied by structural
change of the prominent shock front traced by H2O maser alignments. We have
detected only blue-shifted emissions and all maser features have been
distributed within very small area of 200 200 au in spite of
wide velocity range (> 100 km s). The light curve shows notably
intermittent variation and suggests that the HO masers in G353.273+0.641
are excited by episodic radio jet. The time-scale of \sim2 yr and
characteristic velocity of \sim500 km s also support this
interpretation. Two isolated velocity components of C50 (-53 \pm 7 km s)
and C70 (-73 \pm 7 km s) have shown synchronised linear acceleration of
the flux weighted V_{\rmn{LSR}} values (\sim-5 km s yr) during
the flare phase. This can be converted to the lower-limit momentum rate of 1.1
\times 10 M_{\sun} km s yr. Maser properties are quite
similar to that of IRAS 20126+4104 especially. This corroborates the previous
suggestion that G353.273+0.641 is a candidate of high mass protostellar object.
The possible pole-on geometry of disc-jet system can be suitable for direct
imaging of the accretion disc in this case.Comment: 13 pages, 5 figures accepted for publication in MNRA
A Model System for Dimensional Competition in Nanostructures: A Quantum Wire on a Surface
The retarded Greenâs function (EâH + iÎľ)â1is given for a dimensionally hybrid Hamiltonian which interpolates between one and two dimensions. This is used as a model for dimensional competition in propagation effects in the presence of one-dimensional subsystems on a surface. The presence of a quantum wire generates additional exponential terms in the Greenâs function. The result shows how the location of the one-dimensional subsystem affects propagation of particles
Lymphatic invasion using D2-40 monoclonal antibody and its relationship to lymph node micrometastasis in pN0 gastric cancer
The monoclonal antibody D2-40 is a specific lymphatic endothelial markers and D2-40 staining have been applicable to evaluate lymphatic invasion in various malignant neoplasms. In the present study, we investigated lymph node micrometastasis determined by immunohistochemistry (IHC) and reverse transcriptionâpolymerase chain reaction (RTâPCR) in all dissected lymph nodes obtained from 80 patients with node-negative gastric cancer, and analysed the relationship between micrometastasis and clinicopathological findings including lymphatic invasion of the resected primary tumour using D2-40 immunohistochemical staining. The incidence of micrometastasis determined by IHC and RTâPCR was 11.3% (nine out of 80) and 31.3% (25 out of 80), respectively. Although haematoxylinâeosin (HE) staining revealed lymphatic invasion in 11.3% (nine out of 80) of patients, D2-40 staining uncovered new invasion in 23.8% (19 out of 80) of patients. In the diagnosis of HE and D2-40 staining, the incidence of micrometastasis was significantly higher in patients with lymphatic invasion than in those without lymphatic invasion (P=0.0150 and P<0.0001, respectively). Micrometastasis correlated more closely with D2-40 than with HE staining. We demonstrated a high incidence of micrometastasis and lymphatic invasion and a correlation between them even in pN0 gastric cancer. When planning less invasive treatment, the presence of such occult cancer cells should be considered
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