1,012 research outputs found
Effect of Copper And/Or Bacitracin On The Sulphur Amino Acid Requirements Of Turkeys
A nonsignificant but consistent depressing effects from additions of combined copper (120 ppm) and zinc bacitracin (50 or 75 g per ton) was observed in a previous study. One of the factors that has been suspected to be affected by copper is utilization of sulfur containing amino acids. Thus, a factorial experiment was conducted to study the effect of copper (120 ppm) and/or zinc bacitracin (25 g per ton) on the level of sulfur amino acids at 85%, 100% and 115% of NRC (1977) requirements. The low protein density series of Guenthner et al. (1978) was used (23, 20, 18, 16, 14 and 12%). Dietary protein level was reduced at 4-week intervals
Diagnostic value of Neuron-Specific Enolase (NSE) and Cancer Antigen 15-3 (CA 15-3) in the Diagnosis of Pleural effusions
Introduction: Pleural effusion diagnosis plays an important role in determining treatment strategies. The aim of this study was to determine the diagnostic capacity of tumor markers CA 15-3 and NSE solely or in combination in differentiating the nature of pleural fluid. Methods and Materials: In this cross-sectional study we evaluated 93 patients with pleural effusions (44 malignant and 49 benign). NSE and CA 15-3 serum and pleural levels were measured simultaneously using immunoenzyme assay kits. Diagnosis was established on the basis of cytological study. Results: Sensitivity and specificity of CA 15-3 serum and pleural level measurement were 70.4%, 49.0%, and 79.5% and 49.0%, respectively. Serum NSE levels had 75.0% sensitivity and 69.4% specificity while the respective pleural figures were 75.0% and 73.5%. The combination of NSE and CA 15-3 serum and pleural levels had the highest sensitivity (93.2%), although combined serum levels had the lowest sensitivity (47.7%). With an accuracy of 74.2%, pleural levels of NSE had the highest diagnostic potential. Conclusion: Measuring NSE and CA 15-3 tumor markers is a suitable approach to distinguish the nature of pleural effusions, with NSE pleural levels demonstrating the highest diagnostic accuracy
A transformerless three-level three-phase boost PWM inverter for PV applications
Abstract: Multilevel converters have seen rising demands in the past decades, due to their increased power ratings, enhanced power quality, low switching losses and reduced electromagnetic interference. Prominent among them are the three‐level (3L) neutral point clamped and the flying capacitor inverter topologies along with their derivatives. Nevertheless, the main drawback of these topologies is the requirement of a front‐end boost DC–DC converter to compensate the high dc‐link voltage demand, which is usually twice the grid peak voltage. This multi‐stage power conversion further pulls down the overall system efficiency. A single‐stage dc–ac power converter with boost capability offer an interesting alternative compared to the two stage approach. Considering this aspect, a novel three‐level three‐phase boost type inverter is introduced in this paper for general‐purpose applications (prominently grid‐connected renewable energy). The proposed inverter would reduce the DC‐link voltage requirement to half using the same or even less number of active and passive components, compared to the conventional three‐level neutral point clamped and flying capacitor family. The principle of operation and theoretical analysis are discussed in detail. The design methodology along with simulation and experimental waveforms for a 5 kVA inverter are presented to prove the concept of the proposed inverter topology for practical applications
The effect of melatonin on expression of p53 and ovarian preantral follicle development isolated from vitrified ovary
Ovarian vitrification is a strategy for conservation of fertility of young female patients, suffering from infertility, due to iatrogenic loss of ovarian function, resulting from chemotherapy and/or radiation therapy. The purpose of this study was to determine the influence of melatonin on expression of p53 and the developmental rate of preantral follicles isolated from vitrified and non-vitrified ovaries. This experimental study was carried out on 40, 14-day-old female mice (NMRI). One ovary from each mouse was used randomly for the vitrification procedure. Preantral follicles with a diameter of 120�140 μm derived from vitrified-warmed and non-vitrified ovarian tissues were cultured individually in α-MEM medium supplemented with or without melatonin. The expression of p53, diameter of follicle, survival rate, and number of antral follicles were compared using post hoc LSD, t test, and chi-square test, respectively in four groups: non-vitrified and non-melatonin (NVNM), non-vitrified and melatonin (NVM), vitrified and non-melatonin (VNM), vitrified and melatonin (VM). p53 gene was expressed in four groups and was strongly expressed in the antral follicles of VNM (p = 0.011). The addition of melatonin increased survival rate and the mean diameter of follicles in vitrified group (p = 0.001). There were no significant differences in antral formation of follicles between different groups. Adding melatonin to culture medium reduced expression of p53 apoptotic gene in vitrified group and improves in vitro maturation and survival rate in isolated follicles from vitrified ovaries. © 2017, Springer-Verlag London Ltd
Computational Fluid Dynamics Simulations at Micro-Scale Stenosis for Microfluidic Thrombosis Model Characterization
Platelet aggregation plays a central role in pathological thrombosis, preventing healthy physiological blood flow within the circulatory system. For decades, it was believed that platelet aggregation was primarily driven by soluble agonists such as thrombin, adenosine diphosphate and thromboxane A2. However, recent experimental findings have unveiled an intriguing but complementary biomechanical mechanism—the shear rate gradients generated from flow disturbance occurring at sites of blood vessel narrowing, otherwise known as stenosis, may rapidly trigger platelet recruitment and subsequent aggregation. In our Nature Materials 2019 paper [1], we employed microfluidic devices which incorporated micro-scale stenoses to elucidate the molecular insights underlying the prothrombotic effect of blood flow disturbance. Nevertheless, the rheological mechanisms associated with this stenotic microfluidic device are poorly characterized. To this end, we developed a computational fluid dynamics (CFD) simulation approach to systematically analyze the hemodynamic influence of bulk flow mechanics and flow medium. Grid sensitivity studies were performed to ensure accurate and reliable results. Interestingly, the peak shear rate was significantly reduced with the device thickness, suggesting that fabrication of microfluidic devices should retain thicknesses greater than 50 µm to avoid unexpected hemodynamic aberration, despite thicker devices raising the cost of materials and processing time of photolithography. Overall, as many groups in the field have designed microfluidic devices to recapitulate the effect of shear rate gradients and investigate platelet aggregation, our numerical simulation study serves as a guideline for rigorous design and fabrication of microfluidic thrombosis models
Assessment of Relationship Between Expression of Survivin Protein and Histopathology Diagnosis and Malignancy Severity in Colon Specimen
Background: Survivin is a member of the inhibitor of an apoptosis protein family that has been shown to inhibit apoptosis, promote cell proliferation and enhance angiogenesis. In this study, the survivin protein expression in normal, colon polyp, and adenocarcinoma tissues was investigated. Methods: Immunohistochemical staining for nuclear survivin was carried out on 45 normal colon tissue samples, 38 samples of a colonic polyp, and 37 cases of colon adenocarcinoma operated by colonoscopy or colectomy. The percentages of cells that expressed survivin were classified qualitatively into four categories (0, 1+, 2+, and 3+) based on the intensity of staining and the percentage of cells. An area of samples with colon polyp diagnosis or colon adenocarcinoma that had no microscopic pathology was considered as normal tissues. Results: Survivin protein expression was negative in all cases of normal colon tissue samples while it was expressed in 31 out of 38 colon polyp specimens (81.5) and in 35 out of 37 (94.5) colon adenocarcinoma samples. Amount of expression in the colon adenocarcinoma (p < 0.001) was significantly higher than the amount of expression in the colon polyp. There was not a significant correlation between the survivin protein expression and the low and high grade adenocarcinoma (p = 0.874). Conclusions: Survivin protein was not expressed in normal colon tissues and its amount was higher in the colonic adenocarcinoma compared to the colon polyp. Due to the variations in the intensity of expression in colon polyp (changing from negative to + 3), this marker cannot be used for differentiating the polyp from the adenocarcinoma. © 2019, Springer Science+Business Media, LLC, part of Springer Nature
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Reduced disease severity following therapeutic treatment with angiotensin 1-7 in a mouse model of multiple sclerosis
Multiple Sclerosis (MS) is a chronic disease of the central nervous system (CNS) characterized by autoimmune and neurodegenerative pathologies for which there is no cure and no defined etiology. Although several, modestly effective, disease modifying drugs are available to treat MS, there are presently no treatments that offer neuroprotection and prevent clinical progression. Therapies are needed that control immune homeostasis, prevent disease progression, and stimulate regeneration in the CNS. Components of the renin-angiotensin-system (RAS) have recently been identified as chemical mediators in the CNS and in neurological disease. Here we show the beneficial effect of therapeutic treatment with the Mas receptor agonist and metabolite of the protective arm of RAS, angiotensin 1-7 (A(1-7)), in the experimental autoimmune encephalomyelitis (EAE) animal model of MS. Therapeutic treatment with A(1-7) caused a dose-dependent reduction both in clinical disease severity and progression, and was dependent on Mas receptor activation. Further analysis of the most optimal dose of A(1-7) treatment revealed that the reductions in clinical disease course were associated with decreased immune infiltration and demyelination, axonal loss and oxidative stress in the spinal cord. In addition A(1-7) treatment was also associated with increases in circulating alternatively activated monocytes/macrophages.Department of Defense, USC Clinical and Translational Science Institute, National Multiple Sclerosis Society12 month embargo; available online 25 February 2019.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Non-compact Topological Branes on Conifold
We consider non-compact branes in topological string theories on a class of
Calabi-Yau spaces including the resolved conifold and its mirror. We compute
the amplitudes of the insertion of non-compact Lagrangian branes in the A-model
on the resolved conifold in the context of the topological vertex as well as
the melting crystal picture. They all agree with each other and also agree with
the results from Chern-Simons theory, supporting the large N duality. We find
that they obey the Schr\"odinger equation confirming the wavefunction behavior
of the amplitudes. We also compute the amplitudes of the non-compact B-branes
in the DV matrix model which arises as a B-model open string field theory on
the mirror manifold of the deformed conifold. We take the large N duality to
consider the B-model on the mirror of the resolved conifold and confirm the
wave function behavior of this amplitude. We find appropriate descriptions of
non-compact branes in each model, which give complete agreements among those
amplitudes and clarify the salient features including the role of symmetries
toward these agreements.Comment: 32 pages, 9 figures, a reference added, typos fixe
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