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Search Results: 1 - 10 of 4996 matches for " Russell Christensen4 "
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The role of the microenvironment in tumor immune surveillance
Oluwadayo Oluwadara,Luca Giacomelli,Xenia Brant,Russell Christensen4
Bioinformation , 2011,
Abstract: The evidence appears compelling that the microenvironment, and associated biological cellular and molecular factors, may contribute to the progression of a variety of tumors. The effects of the microenvironment may directly influence the plasticity of T cell lineages, which was recently discussed (O’Shea & Paul, 2010 ). To review the putative role of the microenvironment in modulating the commitment of tumor immune surveillance, we use the model of oral premalignant lesions.
Comparison of three molecular methods for the detection and speciation of Plasmodium vivax and Plasmodium falciparum
Prapaporn Boonma, Peter R Christensen, Rossarin Suwanarusk, Ric N Price, Bruce Russell, Usa Lek-Uthai
Malaria Journal , 2007, DOI: 10.1186/1475-2875-6-124
Abstract: The sensitivity, specificity and cost effectiveness of three molecular techniques were compared for the detection and speciation of Plasmodium falciparum and Plasmodium vivax from dried blood spots collected from 136 patients in western Thailand. The results from the three molecular speciation techniques (nested PCR, multiplex PCR, and real-time PCR) were used to develop a molecular consensus (two or more identical PCR results) as an alternative gold standard.According to the molecular consensus, 9.6% (13/136) of microscopic diagnoses yielded false negative results. Multiplex PCR failed to detect P. vivax in three mixed isolates, and the nested PCR gave a false positive P. falciparum result in one case. Although the real-time PCR melting curve analysis was the most expensive method, it was 100% sensitive and specific and least time consuming of the three molecular techniques investigated.Although microscopy remains the most appropriate method for clinical diagnosis in a field setting, its use as a gold standard may result in apparent false positive results by superior techniques. Future studies should consider using more than one established molecular methods as a new gold standard to assess novel malaria diagnostic kits and PCR assays.In 2005 more than three billion people were at risk of malaria infection [1]. In addition to Plasmodium falciparum there are four other malaria species known to infect humans; Plasmodium vivax, Plasmodium ovale, Plasmodium malariae and Plasmodium knowlesi [2].Since P. falciparum infections are potentially fatal, quick and accurate diagnosis is vital for the effective treatment of this parasitic disease with artemisinin combination therapy (ACT) [3]. In Thailand, chloroquine remains the first line treatment of P. vivax since it is a safe and cost effective anti-malarial and its long half-life protects the patient from the first relapse after treatment. The current "gold standard" for Plasmodium spp. speciation is microscopic examinatio
The Equation of the Universe (According to the Theory of Relation)  [PDF]
Russell Bagdoo
Journal of Modern Physics (JMP) , 2019, DOI: 10.4236/jmp.2019.103022
Abstract: A new equation is found in which the concept of matter-space-time is mathematically connected; gravitation and electromagnetism are also bound by space-time. A mechanism is described showing how velocity, time, distance, matter, and energy are correlated. We are led to ascertain that gravity and electricity are two distinct manifestations of a single underlying process: electro-gravitation. The force of gravitation arises of electromagnetism—inherently much stronger—divided by the cosmological space-time. The radius of space-time belongs to the family of electromagnetic waves: the wavelength is the radius (1026 m) of the universe and the period (1017 s) is its cosmological age. For the first time, the cosmological time, considered as a real physical object, is integrated into a “cosmological equation” which makes coherent what we know regarding the time (its origin, its flow …), the matter, and space. It sets up a mathematical model allowing us to interpret dark energy (or cosmological constant) as being both “negative” and “tired” energy. After an introduction with a brief history of unifications and the presentation of two roughly equal ratios arising out from Dirac’s large-number hypotheses which relate to the ratio of electric force to gravitational force and the ratio of the age of the universe to the atomic time unit associated with atomic processes, we present in §2 this new equation of quantum cosmology which operates the reconciliation between the macrocosm and the microcosm. In §3 and §4, we discuss the irreversible cosmological time resulting from the equation, as well as the role of the mass (heavy) relative to the gravitational constant G. In §5 we discuss the links that the equation establishes between gravitation (structure of condensation) and electromagnetism (structure of expansion), between relativity and quantum theory. We apply the formula to Planck’s time. We speak of the new essential variable? ?\"\", and briefly of a new principle, the principle of compensation. In §6 we discuss the negative energy solutions banned by physics, and we deplore that half of the universe escapes us. We present the electro-gravitation in §7, from the equation which represents a super hydrogen atom. In § 8 we show that the global mass (gravitational) is variable: it increases during the expansion while the mass of the elementary
Scenario for the Origin of Matter (According to the Theory of Relation)  [PDF]
Russell Bagdoo
Journal of Modern Physics (JMP) , 2019, DOI: 10.4236/jmp.2019.102013
Abstract: Where did matter in the universe come from? Where does the mass of matter come from? Particle physicists have used the knowledge acquired in matter and space to imagine a standard scenario to provide satisfactory answers to these major questions. The dominant thought to explain the absence of antimatter in nature is that we had an initially symmetrical universe made of matter and antimatter and that a dissymmetry would have sufficed for more matter having constituted our world than antimatter. This dissymmetry would arise from an anomaly in the number of neutrinos resulting from nuclear reactions which suggest the existence of a new type of titanic neutrino who would exceed the possibilities of the standard model and would justify the absence of antimatter in the macrocosm. We believe that another scenario could better explain why we observe only matter. It involves the validation of the negative energy solution of the Dirac equation, itself derived from the Einstein energy equation. The theory of Relation describes a negative energy ocean with the creation of real particle/antiparticle pairs. The origin of the masses of the particles would come from this ocean. A physical mechanism would allow their separation in the opposite direction and, therefore, the matter would be enriched at the expense of the ocean. The matter would be favored without resorting to negation or annihilation of negative energy, without the need for a CP (the behavioral difference between particle and antiparticle) violation that would be responsible for matter/antimatter asymmetry in the universe. And without the savior contribution of an undetectable obese neutrino: his search appears to us more a desperate act towards an “ultra-massive catastrophe” than a real effort to try to discover what really happened.
Modelling ultrasound-induced mild hyperthermia of hyperplasia in vascular grafts
Mark R Brinton, Russell J Stewart, Alfred K Cheung, Douglas A Christensen, Yan-Ting E Shiu
Theoretical Biology and Medical Modelling , 2011, DOI: 10.1186/1742-4682-8-42
Abstract: Ultrasound beams from two transducers (1.5 and 3.2 MHz) were simulated in two graft/tissue models, with and without an intra-graft cellular layer mimicking hyperplasia, using the finite-difference time-domain (FDTD) method. The resulting power deposition patterns were used as a heat source for the Pennes bioheat equation in a COMSOL? Multiphysics heat transfer model. 50°C is known to cause cell death and therefore the transducer powers were adjusted to produce a 13°C temperature rise from 37°C in the ePTFE.Simulations showed that both the frequency of the transducers and the presence of hyperplasia significantly affect the power deposition patterns and subsequent temperature profiles on the grafts and nearby tissues. While neither transducer significantly raised the temperature of the blood, the 1.5-MHz transducer was less focused and heated larger volumes of the graft and nearby soft tissues than the 3.2-MHz transducer. The presence of hyperplasia had little effect on the blood's temperature, but further increased the temperature of the graft and nearby soft tissues in response to either transducer. Skin cooling and blood flow play a significant role in preventing overheating of the native tissues.Modelling shows that ultrasound can selectively heat ePTFE grafts and produce temperatures that cause cell death on the graft. The temperature increase in blood is negligible and that in the adjacent soft tissues may be minimized by skin cooling and using appropriate transducers. Therefore, ultrasound heating may have the potential to reduce neointimal hyperplasia and failure of ePTFE vascular grafts.There are two primary types of permanent hemodialysis accesses, native arteriovenous (AV) fistulae and expanded-polytetrafluoroethylene (ePTFE) AV grafts. When compared to the fistula, AV grafts provide vascular access with higher blood flow rates, do not require a maturation period, and can be used sooner after surgical placement. Grafts are a particularly useful form of vas
Diets high in selenium and isoflavones decrease androgen-regulated gene expression in healthy rat dorsolateral prostate
Russell L Legg, Jessica R Tolman, Cameron T Lovinger, Edwin D Lephart, Kenneth DR Setchell, Merrill J Christensen
Reproductive Biology and Endocrinology , 2008, DOI: 10.1186/1477-7827-6-57
Abstract: Male Noble rats were exposed from conception until 200 days of age to diets containing an adequate (0.33-0.45 mg/kg diet) or high (3.33-3.45 mg/kg) concentration of selenium as Se-methylselenocysteine and a low (10 mg/kg) or high (600 mg/kg) level of isoflavones in a 2 × 2 factorial design. Gene expression in the dorsolateral prostate was determined for the androgen receptor, for androgen-regulated genes, and for Akr1c9, whose product catalyzes the reduction of dihydrotestosterone to 5alpha-androstane-3alpha, 17beta-diol. Activity of hepatic glutathione peroxidise 1 and of prostatic 5alpha reductase were also assayed.There were no differences due to diet in activity of liver glutathione peroxidase activity. Total activity of 5alpha reductase in prostate was significantly lower (p = 0.007) in rats fed high selenium/high isoflavones than in rats consuming adequate selenium/low isoflavones. High selenium intake reduced expression of the androgen receptor, Dhcr24 (24-dehydrocholesterol reductase), and Abcc4 (ATP-binding cassette sub-family C member 4). High isoflavone intake decreased expression of Facl3 (fatty acid CoA ligase 3), Gucy1a3 (guanylate cyclase alpha 3), and Akr1c9. For Abcc4 the combination of high selenium/high isoflavones had a greater inhibitory effect than either treatment alone. The effects of selenium on gene expression were always in the direction of chemopreventionThese results suggest that combined intake of high selenium and high isoflavones may achieve a greater chemopreventive effect than either compound supplemented individually.Prostate cancer is the most frequently diagnosed cancer in American men and the second leading cause of all cancer deaths in men. The American Cancer Society estimates that there will be about 186,320 new cases of prostate cancer in the United States in 2008. About 28,660 men will die of this disease [1]. Because of its high occurrence and long latency period, prostate cancer is an ideal candidate for chemoprevention b
Pressure-induced phonon frequency shifts in transition-metal nitrides
Xiao-Jia Chen,Viktor V. Struzhkin,Simon Kung,Ho-kwang Mao,Russell J. Hemley,Axel N. Christensen
Physics , 2004, DOI: 10.1103/PhysRevB.70.014501
Abstract: We report the first experiments on the high pressure phonon spectra of transition-metal nitrides HfN, ZrN, and NbN, obtained by Raman scattering measurements. Two pronounced bands, which are related to the acoustic part at low frequency around 200 cm$^{-1}$ and the optical part at high frequency around 550 cm$^{-1}$ of the phonon spectrum, respectively, shift to high frequency values with increasing pressure. An analysis of the results allows us to reproduce the experimental pressure dependence of the superconducting transition temperature $T_{c}$ of ZrN and NbN.
GT 4
Revista Brasileira de Ecoturismo , 2012,
Abstract: O desenvolvimento de atividades turísticas no espa o rural está associado ao processo de urbaniza o que ocorre na sociedade e no transbordamento do espa o urbano para o espa o rural e, neste sentido, "novas" formas de ocupa o passaram a proliferar no campo. Destarte, o objetivo deste eixo temático é o de analisar o turismo rural e, como ele vem desempenhando papel importante no processo de transforma o desse espa o, como novas re-significa es, além de conhecer as características das abordagens da produ o familiar e suas estratégias de sobrevivência, sejam através de empregos agrícolas ou n o-agrícolas, processos fundamentais para o desenvolvimento do turismo com base local. Coordena o: Profa. Dra. Maria Geralda de Almeida (UFG) e Profa. Dra. Marlene Huebes Novais (UNIVALI), Prof. Dr. Giovanni de Farias Seabra (UFPB)
Relativized Quantum Physics Generating N-Valued Coulomb Force and Atomic Hydrogen Energy Spectrum  [PDF]
Walter J. Christensen Jr.
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.63025
Abstract: Though not well-known, Einstein endeavored much of his life to general-relativize quantum mechanics, (rather than quantizing gravity). Albeit he did not succeed, his legacy lives on. In this paper, we begin with the general relativistic field equations describing flat spacetime, but stimulated by vacuum energy fluctuations. In our precursor paper, after straightforward general relativistic calculations, the resulting covariant and contravariant energy-momentum tensors were identified as n-valued operators describing graviton excitation. From these two operators, we were able to generate all three boson masses (including the Higgs mass) in precise agreement as reported in the 2010 CODATA (NIST); moreover local, as-well-as large-scale, accelerated spacetimes were shown to naturally occur from this general relativized quantum physics approach (RQP). In this paper, applying the same approach, we produce an n-valued Coulombs Force Law leading to the energy spectrum for atomic hydrogen, without assuming quantized atomic radii, velocity and momentum, as Bohr did.
Einstein’s Gravitational Field Approach to Dark Matter and Dark Energy—Geometric Particle Decay into the Vacuum Energy Generating Higgs Boson and Heavy Quark Mass  [PDF]
Walter James Christensen
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.610147
Abstract: During an interview at the Niels Bohr Institute David Bohm stated, “according to Einstein, particles should eventually emerge … as singularities, or very strong regions of stable pulses of (the gravitational) field” [1]. Starting from this premise, we show spacetime, indeed, manifests stable pulses (n-valued gravitons) that decay into the vacuum energy to generate all three boson masses (including Higgs), as well as heavy-quark mass; and all in precise agreement with the 2010 CODATA report on fundamental constants. Furthermore, our relativized quantum physics approach (RQP) answers to the mystery surrounding dark energy, dark matter, accelerated spacetime, and why ordinary matter dominates over antimatter.
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