180 research outputs found

    Structural phase control of (La1.48_{1.48}Nd0.40_{0.40}Sr0.12_{0.12})CuO4_4 thin films by epitaxial growth technique

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    Epitaxial growth of (La1.48_{1.48}Nd0.40_{0.40}Sr0.12_{0.12})CuO4_4 thin films was studied by pulsed-laser deposition technique on three different substrates, SrTiO3_3 (100), LaSrAlO4_4 (001), and YAlO3_3 (001). The (Nd,Sr,Ce)2_2CuO4_4-type structure appears at the initial growth stage on SrTiO3_3 (100) when the film is deposited under the growth conditions optimized for (La,Sr)2_2CuO4_4. This (Nd,Sr,Ce)2_2CuO4_4-type structure can be eliminated by increasing the substrate temperature and the laser repetition frequency. Films on LaSrAlO4_4 (001) maintain a La2_2CuO4_4-type structure as bulk samples, but those on YAlO3_3 (001) show phase separation into La2_2CuO4_4- and Nd2_2CuO4_4-type structures. Such complicated results are explained in terms of the competition between lattice misfit and thermodynamic conditions. Interestingly the films with La2_2CuO4_4-type structure prepared on SrTiO3_3 and LaSrAlO4_4 show different surface structures and transport properties. The results indicate the possibility of controlling charge stripes of (La1.48_{1.48}Nd0.40_{0.40}Sr0.12_{0.12})CuO4_4 as was demonstrated in (La,Ba)2_2CuO4_4 thin films by Sato et al. (Phys. Rev. B {\bf 62}, R799 (2000)).Comment: 5 pages, 6 EPS figure, accepted for publication in Phys. Rev.

    Cortical Factor Feedback Model for Cellular Locomotion and Cytofission

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    Eukaryotic cells can move spontaneously without being guided by external cues. For such spontaneous movements, a variety of different modes have been observed, including the amoeboid-like locomotion with protrusion of multiple pseudopods, the keratocyte-like locomotion with a widely spread lamellipodium, cell division with two daughter cells crawling in opposite directions, and fragmentations of a cell to multiple pieces. Mutagenesis studies have revealed that cells exhibit these modes depending on which genes are deficient, suggesting that seemingly different modes are the manifestation of a common mechanism to regulate cell motion. In this paper, we propose a hypothesis that the positive feedback mechanism working through the inhomogeneous distribution of regulatory proteins underlies this variety of cell locomotion and cytofission. In this hypothesis, a set of regulatory proteins, which we call cortical factors, suppress actin polymerization. These suppressing factors are diluted at the extending front and accumulated at the retracting rear of cell, which establishes a cellular polarity and enhances the cell motility, leading to the further accumulation of cortical factors at the rear. Stochastic simulation of cell movement shows that the positive feedback mechanism of cortical factors stabilizes or destabilizes modes of movement and determines the cell migration pattern. The model predicts that the pattern is selected by changing the rate of formation of the actin-filament network or the threshold to initiate the network formation

    Multiband Fitting to Three Long GRBs with Fermi/LAT Data: Structured Ejecta Sweeping up a Density-Jump Medium

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    We present broadband (radio, optical, X-ray and GeV) fits to the afterglow light curves and spectra of three long-duration gamma-ray bursts (GRBs 080916C, 090902B, and 090926A) detected by the Gamma-Ray Burst Monitor (GBM) and Large Area Telescope (LAT) instruments on the Fermi satellite. Using the observed broadband data, we study the origin of the high energy emission, and suggest that the early-time GeV emission and the late-time radio, optical, and X-ray afterglows can be understood as being due to synchrotron emission from an external forward shock caused by structured ejecta propagating in a wind bubble jumping to a homogeneous density medium. If the ceasing time for majority of the energy injection is assumed to be close to the deceleration time of the forward shock, the structured ejecta with continuous energy injection to the forward shock can well explain the early rising feature of the GeV mission from these burst, and the density-jump medium can account for some certain plateaus or flares in the late afterglows. From our fits, we find that, on one hand, the external shock origin of the GeV photons will make the optical depth have not significant contribution to the early LAT rising part, which will loosen strong constraint of lower limits of Lorentz factor. On the other hand, these Fermi-LAT events preferentially occur in a low-density circumburst environment, in which case the Klein-Nishina cutoff will significantly suppress the Self-Synchrotron Compton (SSC) radiation. Such an environment might result from superbubbles or low-metallicity progenitor stars (which have a low mass-loss rate at late times of stellar evolution) of type Ib/c supernovae.Comment: 32 pages, 4 figures, 2 tables; some minor typo corrected, optical depth does not have significant contribution to the result, major conclusions unchange

    Association between Genetic Polymorphism of Multidrug Resistance 1 Gene and Sasang Constitutions

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    Multidrug resistance 1 (MDR1) is a gene that expresses P-glycoprotein (P-gp), a drug transporter protein. Genetic polymorphisms of MDR1 can be associated with Sasang constitutions because Sasang constitutional medicine (SCM) prescribes different drugs according to different constitutions. A Questionnaire for Sasang Constitution Classification II (QSCC II) was used to diagnose Sasang constitutions. Two hundred and seven healthy people whose Sasang constitutions had been identified were tested. Genotype analyses, restriction fragment length polymorphism (RFLP) and pyrosequencing were used in MDR1 C1236T, and in MDR1 G2677T/A and C3435T, respectively. Significant differences in MDR1 C1236T genotypes were found between So-yangin and So-eumin. MDR1 G2677T/A genotype also showed significant differences in allele distribution between So-yangin and Tae-eumin. So-yangin and So-eumin showed significant differences in the distribution of both 1236C-2677G-3435C and 1236T-2677G-3435T, haplotypes of MDR1. The genetic polymorphism of the MDR1 gene was thus shown to be an indicator that could distinguish So-yangin from other constitutions

    Equine penile squamous cell carcinoma: expression of biomarker proteins and EcPV2

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    Equine penile squamous cell carcinoma (EpSCC) is a relatively common cutaneous neoplasm with a poor prognosis. In this study, we aimed to determine the protein expression and colocalisation of FRA1, c-Myc, Cyclin D1, and MMP7 in normal (NT), tumour (T), hyperplastic epidermis and/or squamous papilloma (Hyp/Pap), poorly-differentiated (PDSCC), or well-differentiated (WDSCC) EpSCC using a tissue array approach. Further objectives were to correlate protein expression to (i) levels of inflammation, using a convolutional neural network (ii) equine papillomavirus 2 (EcPV2) infection, detected using PCR amplification. We found an increase in expression of FRA1 in EpSCC compared to NT samples. c-Myc expression was higher in Hyp/Pap and WDSCC but not PDSCC whereas MMP7 was reduced in WDSCC compared with NT. There was a significant increase in the global intersection coefficient (GIC) of FRA1 with MMP7, c-Myc, and Cyclin D1 in EpSCC. Conversely, GIC for MMP7 with c-Myc was reduced in EpSCC tissue. Inflammation was positively associated with EcPV2 infection in both NT and EpSCC but not Hyp/Pap. Changes in protein expression could be correlated with EcPV2 for Cyclin D1 and c-Myc. Our results evaluate novel biomarkers of EpSCC and a putative correlation between the expression of biomarkers, EcPV2 infection and inflammation

    Balancing selection is common in the extended MHC region but most alleles with opposite risk profile for autoimmune diseases are neutrally evolving

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    <p>Abstract</p> <p>Background</p> <p>Several susceptibility genetic variants for autoimmune diseases have been identified. A subset of these polymorphisms displays an opposite risk profile in different autoimmune conditions. This observation open interesting questions on the evolutionary forces shaping the frequency of these alleles in human populations.</p> <p>We aimed at testing the hypothesis whereby balancing selection has shaped the frequency of opposite risk alleles.</p> <p>Results</p> <p>Since balancing selection signatures are expected to extend over short genomic portions, we focused our analyses on 11 regions carrying putative functional polymorphisms that may represent the disease variants (and the selection targets). No exceptional nucleotide diversity was observed for <it>ZSCAN23</it>, <it>HLA-DMB</it>, <it>VARS2</it>, <it>PTPN22</it>, <it>BAT3</it>, <it>C6orf47</it>, and <it>IL10</it>; summary statistics were consistent with evolutionary neutrality for these gene regions. Conversely, <it>CDSN/PSORS1C1</it>, <it>TRIM10/TRIM40</it>, <it>BTNL2</it>, and <it>TAP2 </it>showed extremely high nucleotide diversity and most tests rejected neutrality, suggesting the action of balancing selection. For <it>TAP2 </it>and <it>BTNL2 </it>these signatures are not secondary to linkage disequilibrium with HLA class II genes. Nonetheless, with the exception of variants in <it>TRIM40 </it>and <it>CDSN</it>, our data suggest that opposite risk SNPs are not selection targets but rather have accumulated as neutral variants.</p> <p>Conclusion</p> <p>Data herein indicate that balancing selection is common within the extended MHC region and involves several non-HLA loci. Yet, the evolutionary history of most SNPs with an opposite effect for autoimmune diseases is consistent with evolutionary neutrality. We suggest that variants with an opposite effect on autoimmune diseases should not be considered a distinct class of disease alleles from the evolutionary perspective and, in a few cases, the opposite effect on distinct diseases may derive from complex haplotype structures in regions with high genetic diversity.</p

    Wetlands for wastewater treatment and subsequent recycling of treated effluent : a review

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    Due to water scarcity challenges around the world, it is essential to think about non-conventional water resources to address the increased demand in clean freshwater. Environmental and public health problems may result from insufficient provision of sanitation and wastewater disposal facilities. Because of this, wastewater treatment and recycling methods will be vital to provide sufficient freshwater in the coming decades, since water resources are limited and more than 70% of water are consumed for irrigation purposes. Therefore, the application of treated wastewater for agricultural irrigation has much potential, especially when incorporating the reuse of nutrients like nitrogen and phosphorous, which are essential for plant production. Among the current treatment technologies applied in urban wastewater reuse for irrigation, wetlands were concluded to be the one of the most suitable ones in terms of pollutant removal and have advantages due to both low maintenance costs and required energy. Wetland behavior and efficiency concerning wastewater treatment is mainly linked to macrophyte composition, substrate, hydrology, surface loading rate, influent feeding mode, microorganism availability, and temperature. Constructed wetlands are very effective in removing organics and suspended solids, whereas the removal of nitrogen is relatively low, but could be improved by using a combination of various types of constructed wetlands meeting the irrigation reuse standards. The removal of phosphorus is usually low, unless special media with high sorption capacity are used. Pathogen removal from wetland effluent to meet irrigation reuse standards is a challenge unless supplementary lagoons or hybrid wetland systems are used

    Multifaceted roles of GSK-3 and Wnt/β-catenin in hematopoiesis and leukemogenesis: opportunities for therapeutic intervention

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    Glycogen synthase kinase-3 (GSK-3) is well documented to participate in a complex array of critical cellular processes. It was initially identified in rat skeletal muscle as a serine/threonine kinase that phosphorylated and inactivated glycogen synthase. This versatile protein is involved in numerous signaling pathways that influence metabolism, embryogenesis, differentiation, migration, cell cycle progression and survival. Recently, GSK-3 has been implicated in leukemia stem cell pathophysiology and may be an appropriate target for its eradication. In this review, we will discuss the roles that GSK-3 plays in hematopoiesis and leukemogenesis as how this pivotal kinase can interact with multiple signaling pathways such as: Wnt/β-catenin, phosphoinositide 3-kinase (PI3K)/phosphatase and tensin homolog (PTEN)/Akt/mammalian target of rapamycin (mTOR), Ras/Raf/MEK/extracellular signal-regulated kinase (ERK), Notch and others. Moreover, we will discuss how targeting GSK-3 and these other pathways can improve leukemia therapy and may overcome therapeutic resistance. In summary, GSK-3 is a crucial regulatory kinase interacting with multiple pathways to control various physiological processes, as well as leukemia stem cells, leukemia progression and therapeutic resistance. GSK-3 and Wnt are clearly intriguing therapeutic targets

    Canagliflozin and Cardiovascular and Renal Outcomes in Type 2 Diabetes Mellitus and Chronic Kidney Disease in Primary and Secondary Cardiovascular Prevention Groups

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    Background: Canagliflozin reduces the risk of kidney failure in patients with type 2 diabetes mellitus and chronic kidney disease, but effects on specific cardiovascular outcomes are uncertain, as are effects in people without previous cardiovascular disease (primary prevention). Methods: In CREDENCE (Canagliflozin and Renal Events in Diabetes With Established Nephropathy Clinical Evaluation), 4401 participants with type 2 diabetes mellitus and chronic kidney disease were randomly assigned to canagliflozin or placebo on a background of optimized standard of care. Results: Primary prevention participants (n=2181, 49.6%) were younger (61 versus 65 years), were more often female (37% versus 31%), and had shorter duration of diabetes mellitus (15 years versus 16 years) compared with secondary prevention participants (n=2220, 50.4%). Canagliflozin reduced the risk of major cardiovascular events overall (hazard ratio [HR], 0.80 [95% CI, 0.67-0.95]; P=0.01), with consistent reductions in both the primary (HR, 0.68 [95% CI, 0.49-0.94]) and secondary (HR, 0.85 [95% CI, 0.69-1.06]) prevention groups (P for interaction=0.25). Effects were also similar for the components of the composite including cardiovascular death (HR, 0.78 [95% CI, 0.61-1.00]), nonfatal myocardial infarction (HR, 0.81 [95% CI, 0.59-1.10]), and nonfatal stroke (HR, 0.80 [95% CI, 0.56-1.15]). The risk of the primary composite renal outcome and the composite of cardiovascular death or hospitalization for heart failure were also consistently reduced in both the primary and secondary prevention groups (P for interaction &gt;0.5 for each outcome). Conclusions: Canagliflozin significantly reduced major cardiovascular events and kidney failure in patients with type 2 diabetes mellitus and chronic kidney disease, including in participants who did not have previous cardiovascular disease

    Canagliflozin and Renal Outcomes in Type 2 Diabetes and Nephropathy

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    BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to 300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m 2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years
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