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Search Results: 1 - 10 of 2753 matches for " Guido Frosina "
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The Bright and the Dark Sides of DNA Repair in Stem Cells
Guido Frosina
Journal of Biomedicine and Biotechnology , 2010, DOI: 10.1155/2010/845396
Abstract: DNA repair is a double-edged sword in stem cells. It protects normal stem cells in both embryonic and adult tissues from genetic damage, thus allowing perpetuation of intact genomes into new tissues. Fast and efficient DNA repair mechanisms have evolved in normal stem and progenitor cells. Upon differentiation, a certain degree of somatic mutations becomes more acceptable and, consequently, DNA repair dims. DNA repair turns into a problem when stem cells transform and become cancerous. Transformed stem cells drive growth of a number of tumours (e.g., high grade gliomas) and being particularly resistant to chemo- and radiotherapeutic agents often cause relapses. The contribution of DNA repair to resistance of these tumour-driving cells is the subject of intense research, in order to find novel agents that may sensitize them to chemotherapy and radiotherapy.
Accelerated Repair and Reduced Mutagenicity of DNA Damage Induced by Cigarette Smoke in Human Bronchial Cells Transfected with E.coli Formamidopyrimidine DNA Glycosylase
Mara Foresta, Alberto Izzotti, Sebastiano La Maestra, Rosanna Micale, Alessandro Poggi, Donatella Vecchio, Guido Frosina
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0087984
Abstract: Cigarette smoke (CS) is associated to a number of pathologies including lung cancer. Its mutagenic and carcinogenic effects are partially linked to the presence of reactive oxygen species and polycyclic aromatic hydrocarbons (PAH) inducing DNA damage. The bacterial DNA repair enzyme formamidopyrimidine DNA glycosylase (FPG) repairs both oxidized bases and different types of bulky DNA adducts. We investigated in vitro whether FPG expression may enhance DNA repair of CS-damaged DNA and counteract the mutagenic effects of CS in human lung cells. NCI-H727 non small cell lung carcinoma cells were transfected with a plasmid vector expressing FPG fused to the Enhanced Green Fluorescent Protein (EGFP). Cells expressing the fusion protein EGFP-FPG displayed accelerated repair of adducts and DNA breaks induced by CS condensate. The mutant frequencies induced by low concentrations of CS condensate to the Na+K+-ATPase locus (ouar) were significantly reduced in cells expressing EGFP-FPG. Hence, expression of the bacterial DNA repair protein FPG stably protects human lung cells from the mutagenic effects of CS by improving cells’ capacity to repair damaged DNA.
SECESSION AND SELF-DETERMINATION OF PEOPLE IN INTERNATIONAL LAW: The case of former Yugoslavia
Frosina T. REMENSKI
Bezbednosni Dijalozi , 2011,
Abstract: Самоопределува ето е право на секо народ и наци а во светот самосто но да одлучува за сво ата судбина. По принцип на самоопределува е се подразбираат следниве права: право на отцепува е и создава е независна национална држава, право на соединува е со други народи, право на економско самоопределува е, како и право на избор на општествено и политичко уредува е. Повелбата на ООН правото на самоопределува е го спомнува во членот 1 и 55, но без дефиници а за самиот поим. Поимот народ“ се` пове е може да се примени на етно-културните групи во рамките на државата. Правото на самоопределува е има внатрешни и надворешни аспекти. Надворешните аспекти се однесуваат на правото на народот да го одредат ме ународниот статус на територи ата. Ово аспект го уживаат народите од несамоуправните територии, населението на суверени и независни држави,територи ално сконцентрирана популаци а исклучени од авниот и политичкиот живот инаселението на конститутивна единица на етничка федераци а во процес на распа а е. Во сите останати случаи, признава ето на правото на народите на самоопределува е нема вли ание на територи алниот интегритет на суверената и независната држава. Интерните аспекти на правото на самоопределува е го признава правото на сите гра ани слободно да го одредуваат сво от политички статус и слободно постигнува е на економскиот, општествениот и културниот разво . Сепаратизмот е залага е за состо бата на културните, етничките, племенските, верските или политичка автономи на одреден
Liver Carbohydrate Metabolism in Rats in the Period of Recovery after Acute Heat Stress
Biljana Miova,Suzana Dinevska–Kjovkarovska,Frosina Cvetkovska,Slavco Mitev
Macedonian Journal of Medical Sciences , 2013,
Abstract: In the present work we have estimated the effect of acute heat stress (1 hour to 41±0,5°C) and the different period of recovery at room temperature after the heat stress (0, 30 minutes, 1, 6, 12, 24, 48 and 96 hours) over the hepatic carbohydrate-related enzymes and substrates of rats. The obtained results can be summarized in three phases: up to 6th hour, from 6th to 24th hour and form 24th up to 96th hour of recovery after the heat stress. Acute heat stress (up to 1hour of recovery) caused intensive glycogenolysis, associated with moderate, but non-significant endogenous production of glucose. The period of 6th to 24th hour of recovery after exposure to acute heat stress, is characterized with intensive rebound of glycogen stores, with decreased glucose production, and finally, from the 48th up to 96th hour of recovery, process of glycogenolysis is still evident, even though less intensive than the first hours after the heat stress.Overall, we can conclude that acute heat stress and the period of recovery after the heat stress are followed with dynamic changes of the liver carbohydrate-relates enzymes and substrates in a course of elevated glycogenolysis, but decreased glycolysis and gluconeogenesis.
Does Gravitation Have an Influence on Electromagnetism?  [PDF]
Guido Zbiral
Journal of Modern Physics (JMP) , 2012, DOI: 10.4236/jmp.2012.329158
Abstract: For many years physicists have been engaged on research around the globe in fields such as the unification of gravita- tion and electromagnetism, and an explanation for dark matter and dark energy, etc., but so far to little avail. One is left with the impression that something might be fundamentally wrong with the premises underlying the doctrine of physics applicable today, which is preventing a solution of these problems from being found. As a possible cause, the author proposes that the gravitation of the photons is not so negligible that it can be completely ignored (although this assumption does not accord with the current state of physics). Departing therefore from the accepted doctrine, he assumes that gravitation might possess a hitherto unknown important influence on electromagnetism. This paper then examines the consequences of this assumption on physics. A precise analysis will lead to the insight that the gravitation of a photon is as dynamic as the photon itself, and therefore must be taken into account with all associated physical considerations. The hitherto accepted case of a static gravitation of photons, on the other hand, can be totally neglected, as it does not exist for photons. Of key importance is the statement that the gravitation of photons is produced by gravitational quanta, and thus appears in quantised form. It is therefore necessary to rethink the physics of photons. This leads to a number of other interesting insights, as will be borne out in the further course of this paper. In the event that the assumption of the influence of gravitation on electromagnetism turns out to be correct, then this would represent a major step in unravelling the still largely unknown nature of gravitation and its significance in the natural events of the microcosmos; furtheron it would be an important contribution regarding a “New Physics” and a “New Cosmology”.
The “Dynamic Gravitation of Photons: A Hitherto Unknown Physical Quantity”. New Aspects on the Physics of Photons  [PDF]
Guido Zbiral
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.55030
Abstract:

In order to explore the nature of photons, no doubts can be allowed to exist concerning the “physics of photons”. While static gravitation plays no role in the physics of photons, this paper will show that the previously unknown nonbaryonic dynamic gravitation of photons determines not only the external physical behaviour of photons but also, in particular, the hitherto unknown physical events occurring within the photons themselves. For this reason, the paper places particular emphasis on dynamic gravitation as a new hitherto unknown physical quantity. Moreover the new type of gravitation postulated here also provides a plausible explanation of the mysterious nonbaryonic dark matter. As no generally accepted scientific explanation of the creation and essence of dark matter exists to date, it is to be anticipated that the nonbaryonic dynamic gravitation of photons is of general interest to physicists as well as cosmologists and may serve to initiate a general debate among them. Furthermore, this paper will also show that there exists a close mutual relationship between electrodynamics <> dynamic gravitation <> static gravitation <> electrostatics <> electrodynamics (refer to paragraph 4). Due to the fact that the insights into the relationship between photons and their dynamic gravitation have not been described by any other author to date, there exists only a few references that I can cite in support of my paper.

On the Cosmic Ray Sources  [PDF]
Guido Pizzella
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.55034
Abstract:

The cosmic ray energy spectrum is calculated assuming that cosmic rays are generated by astrophysical objects provided by magnetospheres with a dipole magnetic field. With simple geometric considerations, the energy spectrum E-2.5 is obtained, independently on the particle species.

The Dynamic Gravitation of Photons from the Perspective of Maxwell’s Wave Equations  [PDF]
Guido Zbiral
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.512111
Abstract:

Although the gravitational constant (G) does not explicitly occur in the Maxwell Wave Equations, this paper will show that G is indeed implicitly contained in them. The logical consequence hereby is that electromagnetic radiation is associated with dynamic gravitation and notas assumed in Einstein’s Special Theory of Relativitywith “static” gravitation, dynamic gravitation being at the time unknown. According to the Maxwell Wave Equations, gravitation experiences the same dynamic (speed of light c) as electromagnetic radiation and must therefore also be of a quantum nature. There must exist an equal number of gravitational quanta as there are photons. Since photons do not possess a baryonic rest mass but only a relativistic mass, this mass must be nonbaryonic in nature—precisely as their dynamic gravitation.

Ideas on an Alternative Cosmological World Model with Different Initial Conditions  [PDF]
Guido Zbiral
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.63037
Abstract: The actual world model, the “Standard Model of Cosmology” (SMC), which dates back to the 1950s, no longer corresponds to the latest state of knowledge on the cosmos. By way of example, the assumption made in the SMC that the expansion of the cosmos is continually being reduced due to the effect of the gravitation exerted on all the matter in the universe is now contradicted by recent measurements. The reason for the expansion of cosmic space in accordance with Hubble’s Law is not physically explained by the SMC but merely stated as a fact. Another example is provided by the “dark phenomena”, which make up by far the greatest part of the energy of the cosmos, and exert a dominant influence on its behaviour. In spite of intensive research over the decades to provide answers to these as well as other open issues in cosmology, no satisfactory and plausible answers have hitherto been found. It is indeed time to propose an alternative cosmological world model to the SMC in the light of the latest insights on the universe.
Considerations on the Unification of Quantum Physics with the General Theory of Relativity  [PDF]
Guido Zbiral
Journal of Modern Physics (JMP) , 2016, DOI: 10.4236/jmp.2016.710105
Abstract: From a holistic perspective of a physical space of any given size1, it is invariably necessary to consider its energy content, since no physical means exists of making a physical space completely devoid of energy. Such a space would therefore only be a fictive “geometric space”—that can be intellectually conceived and treated according to the rules of the appropriate geometry—although not existing in reality in the cosmos. Cosmic space always contains energy in one form or another, limited by the space under consideration. Therefore, each space possesses an energy density—no matter how low, which never becomes zero. Because of the mass-energy equivalence relationship \"\", cosmic space also possesses a mass equivalent and is therefore “materialistic” in nature. If this is considered in association with Einstein’s space-time, what is obtained instead is an “energy-time”, i.e. an energy effect, which is based on Planck’s action quantum h. Under this condition, a close relationship would appear to exist between the General Theory of Relativity and Quantum Physics. Furthermore, it will be shown that the physical conditions of space are such that a natural quantisation of space and time exists, thus obviating the need for any artificial or arbitrary quantisation.
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