1,368 research outputs found
Multiuser diversity and multiplexing using multiple random beams in wireless systems
In this paper, we propose a new multiple-antenna transmission scheme that can simultaneously achieve both diversity
and multiplexing gain in the multi-user domain, by using multiple random beams. Multiple beams are generated so that
the users encounter multiple channels at the same time, enabling the use of multi-user diversity through each channel. Although
the signal-to-noise power ratio (SNR) of each channel is reduced in proportion to the number of beams, multiple beams are
generated so that the multiplexing gain is larger than the decrease of SNR, increasing the overall system capacity
Role of G{alpha}12 and G{alpha}13 as Novel Switches for the Activity of Nrf2, a Key Antioxidative Transcription Factor
G{alpha}12 and G{alpha}13 function as molecular regulators responding to extracellular stimuli. NF-E2-related factor 2 (Nrf2) is involved in a protective adaptive response to oxidative stress. This study investigated the regulation of Nrf2 by G{alpha}12 and G{alpha}13. A deficiency of G{alpha}12, but not of G{alpha}13, enhanced Nrf2 activity and target gene transactivation in embryo fibroblasts. In mice, G{alpha}12 knockout activated Nrf2 and thereby facilitated heme catabolism to bilirubin and its glucuronosyl conjugations. An oligonucleotide microarray demonstrated the transactivation of Nrf2 target genes by G{alpha}12 gene knockout. G{alpha}12 deficiency reduced Jun N-terminal protein kinase (JNK)-dependent Nrf2 ubiquitination required for proteasomal degradation, and so did G{alpha}13 deficiency. The absence of G{alpha}12, but not of G{alpha}13, increased protein kinase C {delta} (PKC {delta}) activation and the PKC {delta}-mediated serine phosphorylation of Nrf2. G{alpha}13 gene knockout or knockdown abrogated the Nrf2 phosphorylation induced by G{alpha}12 deficiency, suggesting that relief from G{alpha}12 repression leads to the G{alpha}13-mediated activation of Nrf2. Constitutive activation of G{alpha}13 promoted Nrf2 activity and target gene induction via Rho-mediated PKC {delta} activation, corroborating positive regulation by G{alpha}13. In summary, G{alpha}12 and G{alpha}13 transmit a JNK-dependent signal for Nrf2 ubiquitination, whereas G{alpha}13 regulates Rho-PKC {delta}-mediated Nrf2 phosphorylation, which is negatively balanced by G{alpha}12
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Splenectomy is associated with an aggressive tumor growth pattern and altered host immunity in an orthotopic syngeneic murine pancreatic cancer model.
The purpose of this study was to investigate whether splenectomy influences the tumor growth and metastatic pattern in an orthotopic syngeneic murine pancreatic cancer model. Murine pancreatic cancer cells (PAN02) were subcutaneously injected into the flanks of nude mice. A small tumor fragment (3 mm2), harvested from a subcutaneous tumor. was orthotopically implanted in the tail of the pancreas of C57/BL6 mice without splenectomy (control group, n=15) or with simultaneous splenectomy (splenectomy group, n=15). Tumor growth and metastatic patterns were analyzed by laparotomy at 21 days after surgery. No tumor growth was found in 5 mice (33.3%) of the control group and 1 mouse (6.7%) of the splenectomy group (p=0.169). Tumor volume was significantly larger in splenectomy group (p=0.013). Peritoneal seeding was more frequently observed in the splenectomy group (11 (73.3%) vs. 4 (26.7%), p=0.011). There were no differences in the number of liver and kidney metastasis between the two groups. The ratios of tumor-infiltrating CD4+ to FoxP3+ and CD8+ to FoxP3+ were significantly higher in the control group compared to the splenectomy group (8.2 Β± 9.3 vs. 2.4 Β± 1.5, p=0.046; 2.5 Β± 1.4 vs. 1.5 Β± 0.4, p=0.031, respectively). Splenectomy enhanced tumor growth and peritoneal seeding in an orthotopic syngeneic murine pancreatic cancer mouse model. The ramification of these results are discussed for pancreatic cancer treatment
Structure stability evaluation of offshore heave compensator using multi-body dynamics analysis method
Heave compensator attenuate vessel heave motion during drilling operation of drillship. Heave compensator functions as damping form motion of drillship, such as principle spring of suspension system. The load transfers on the parts of heave compensator. Stress and deformation of all parts is evaluated to diagnose the stability of the compensator. This study makes a decision on the safety of structure. Results of analysis confirm the structure stability of heave compensator for simulation. This result can be used as data for structural analysis to determine safety of a structure
Antidiabetic Effect of Fresh Nopal ( Opuntia ficus-indica
The objective of the present study was to evaluate Ξ±-glucosidase inhibitory and antidiabetic effects of Nopal water extract (NPWE) and Nopal dry power (NADP) in low-dose streptozotocin- (STZ-) induced diabetic rats fed a high-fat diet (HFD). The type 2 diabetic rat model was induced by HFD and low-dose STZ. The rats were divided into four groups as follows: (1) nondiabetic rats fed a regular diet (RD-Control); (2) low-dose STZ-induced diabetic rats fed HFD (HF-STZ-Control); (3) low-dose STZ-induced diabetic rats fed HFD and supplemented with NPWE (100βmg/kg body weight, HF-STZ-NPWE); and (4) low-dose STZ-induced diabetic rats fed HFD and supplemented with comparison medication (rosiglitazone, 10βmg/kg, body weight, HF-STZ-Rosiglitazone). In results, NPWE and NADP had IC50 values of 67.33 and 86.68βΞΌg/mL, both of which exhibit inhibitory activities but lower than that of acarbose (38.05βΞΌg/mL) while NPWE group significantly decreased blood glucose levels compared to control and NPDP group on glucose tolerance in the high-fat diet fed rats model (P<0.05). Also, the blood glucose levels of HR-STZ-NPWE group were significantly lower (P<0.05) than HR-STZ-Control group on low-dose STZ-induced diabetic rats fed HFD. Based on these findings, we suggested that NPWE could be considered for the prevention and/or treatment of blood glucose and a potential use as a dietary supplement
Fabrication of layer-by-layer photonic crystals using two polymer microtransfer molding
A method of manufacturing photonic band gap structures operable in the optical spectrum has been presented. The method comprises the steps of filling a plurality of grooves of an elastomeric mold with a UV curable first polymer, each groove in parallel with each other and partially curing the first polymer. A second polymer is coated on the first polymer. A substrate or a multi-layer polymer structure is placed on the filled mold and the resulting structure is exposed to UV light (i.e., is UV cured). The mold is peeled away from the first and second polymers such that a layer of polymer rods is formed on the substrate/multi-layer polymer structure. The process is repeated until a desired number of layers have been formed. The multi-layer structure can be used to create ceramic and metallic photonic band gaps by infiltration, electro-deposition, and/or metal coating
Optical Spectroscopy of Supernova Remnants in M81 and M82
We present spectroscopy of 28 SNR candidates as well as one H II region in
M81, and two SNR candidates in M82. Twenty six out of the M81 candidates turn
out to be genuine SNRs, and two in M82 may be shocked condensations in the
galactic outflow or SNRs. The distribution of [N II]/H{\alpha} ratios of M81
SNRs is bimodal. M81 SNRs are divided into two groups in the spectral line
ratio diagrams: an [O III]-strong group and an [O III]-weak group. The latter
have larger sizes, and may have faster shock velocity. [N II]/H{\alpha} ratios
of the SNRs show a strong correlation with [S II]/H{\alpha} ratios. They show a
clear radial gradient in [N II]/H{\alpha} and [S II]/H{\alpha} ratios: dLog ([N
II]/H{\alpha})/dLog R = -0.018 {\pm} 0.008 dex/kpc and dLog ([S
II]/H{\alpha})/dLog R = -0.016 {\pm} 0.008 dex/kpc where R is a deprojected
galactocentric distance. We estimate the nitrogen and oxygen abundance of the
SNRs from the comparison with shock-ionization models. We obtain a value for
the nitrogen radial gradient, dLog(N/H)/dLogR = -0.023 {\pm} 0.009 dex/kpc, and
little evidence for the gradient in oxygen. This nitrogen abundance shows a few
times flatter gradient than those of the planetary nebulae and H II regions. We
find that five SNRs are matched with X-ray sources. Their X-ray hardness colors
are consistent with thermal SNRs.Comment: 19 pages, 24 figures, 5 tables, ApJ accepte
Proteomic analysis of the extraembryonic tissues from cloned porcine fetus at day 35 of pregnancy
Using Lordotic Cages at the L5βS1 Level Does Not Guarantee the Improvement of Sagittal Alignment in Patients Who Underwent Posterior Lumbar Interbody Fusion
Study Design Retrospective comparative study. Purpose This study aimed to investigate the effects of the lordotic angle of cages on sagittal alignment in patients who underwent 1- or 2-level posterior lumbar interbody fusion (PLIF), including the L5βS1 level. Overview of Literature Few studies have addressed the effects of the lordotic angle of cages on regional and global sagittal balance in patients undergoing PLIF at the L5βS1 level. Methods Sixty-one patients who underwent 1- or 2-level PLIF, including the L5βS1 level, were divided into two groups based on the lordotic angle of cages (4Β° and 8Β° in 41 and 20 patients, respectively). Clinical and radiological parameters were compared. Correlation analyzes were performed to reveal the effect of flexibility and position of cages on the regional sagittal parameters. Results Pre- and postoperative clinical and radiological parameters were not different between the two groups. Although clinical outcomes improved postoperatively, sagittal parameters did not improve postoperatively in both groups. Patients who underwent 1-level PLIF at the L5βS1 level with the use of 8Β° cages showed no postoperative improvement (segmental angle: 16.1Β°β15.9Β°, p=0.140; lumbar lordosis: 44.8Β°β47.8Β°, p=0.740) of regional sagittal parameters. The degree of anterior location of cages showed a positive correlation with the postoperative restoration of the segmental angle (p=0.012 and p=0.050 at 1 and 2 years postoperatively, respectively). Conclusions Clinical and radiological outcomes based on the lordotic angle of cages were not different. Even with the use of 8Β° cages and regardless of the more anterior position of cages, sagittal alignment did not improve in cases involving the L5βS1 level. PLIF at the L5βS1 level should be used with caution because improvement in sagittal alignment did not occur
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