438 research outputs found
Commutative rings in which every finitely generated ideal is quasi-projective
This paper studies the multiplicative ideal structure of commutative rings in
which every finitely generated ideal is quasi-projective. Section 2 provides
some preliminaries on quasi-projective modules over commutative rings. Section
3 investigates the correlation with well-known Prufer conditions; namely, we
prove that this class of rings stands strictly between the two classes of
arithmetical rings and Gaussian rings. Thereby, we generalize Osofsky's theorem
on the weak global dimension of arithmetical rings and partially resolve
Bazzoni-Glaz's related conjecture on Gaussian rings. We also establish an
analogue of Bazzoni-Glaz results on the transfer of Prufer conditions between a
ring and its total ring of quotients. Section 4 examines various contexts of
trivial ring extensions in order to build new and original examples of rings
where all finitely generated ideals are subject to quasi-projectivity, marking
their distinction from related classes of Prufer rings.Comment: 14 page
Gold nanoparticles administration induced prominent inflammatory, central vein intima disruption, fatty change and Kupffer cells hyperplasia
<p>Abstract</p> <p>Background</p> <p>Advances in nanotechnology have identified promising candidates for many biological, biomedical and biomedicine applications. They are being increasingly exploited for medical uses and other industrial applications. The aim of the present study was to investigate the effects of administration of gold nanoparticles (GNPs) on inflammatory cells infiltration, central vein intima disruption, fatty change, and Kupffer cells hyperplasia in the hepatic tissue in an attempt to cover and understand the toxicity and the potential threat of their therapeutic and diagnostic use.</p> <p>Methods</p> <p>A total of 70 healthy male Wistar-Kyoto rats were exposed to GNPs received 50 or 100 μl of GNPs infusion of 10, 20 and 50 nm GNPs for 3 or 7 days. Animals were randomly divided into groups, 12 GNPs-treated rats groups and one control group (NG). Groups 1, 2 and 3 received infusion of 50 μl GNPs of size 10 nm (3 or 7 days), size 20 nm (3 or 7 days) and 50 nm (3 or 7 days), respectively; while groups 4, 5 and 6 received infusion of 100 μl GNPs of size 10 nm, size 20 nm and 50 nm, respectively.</p> <p>Results</p> <p>In comparison with respective control rats, exposure to GNPs doses has produced alterations in the hepatocytes, portal triads and sinusoids. The alterations in the hepatocytes were mainly vacuolar to hydropic degeneration, cytopasmic hyaline vacuolation, polymorphism, binucleation, karyopyknosis, karyolysis, karyorrhexis and necrosis. In addition, inflammatory cell infiltration, Kupffer cells hyperplasia, central veins intima disruption, hepatic strands dilatation and occasional fatty change together with a loss of normal architechiture of hepatic strands were also seen.</p> <p>Conclusions</p> <p>The alterations induced by the administration of GNPs were size-dependent with smaller ones induced more affects and related with time exposure of GNPs. These alterations might be an indication of injured hepatocytes due to GNPs toxicity that became unable to deal with the accumulated residues resulting from metabolic and structural disturbances caused by these NPs. These histological alterations may suggest that GNPs interact with proteins and enzymes of the hepatic tissue interfering with the antioxidant defense mechanism and leading to reactive oxygen species (ROS) generation which in turn may induce stress in the hepatocytes to undergo necrosis.</p
The appearance of renal cells cytoplasmic degeneration and nuclear destruction might be an indication of GNPs toxicity
Gold nanoparticles induced cloudy swelling to hydropic degeneration, cytoplasmic hyaline vacuolation, polymorphism, binucleation, karyopyknosis, karyolysis, karyorrhexis and necrosis in the liver
<p>Abstract</p> <p>Background</p> <p>Nanoparticles (NPs) can potentially cause adverse effects on organ, tissue, cellular, subcellular and protein levels due to their unusual physicochemical properties. Advances in nanotechnology have identified promising candidates for many biological and biomedical applications. The aim of the present study was to investigate the particle-size, dose and exposure duration effects of gold nanoparticles (GNPs) on the hepatic tissue in an attempt to cover and understand the toxicity and their potential therapeutic and diagnostic use.</p> <p>Methods</p> <p>A total of 70 healthy male Wistar-Kyoto rats were exposed to GNPs received 50 or 100 ul of GNPs infusion of size (10, 20 and 50 nm for 3 or 7 days) to investigate particle-size, dose and exposure duration effects of GNPs on the hepatic tissue.</p> <p>Results</p> <p>In comparison with respective control rats, exposure to GNPs doses has produced alterations in the hepatocytes, portal triads and the sinusoids. The alterations in the hepatocytes were mainly vacuolar to hydropic degeneration, cytopasmic hyaline vacuolation, polymorphism, binucleation, karyopyknosis, karyolysis, karyorrhexis and necrosis.</p> <p>Conclusions</p> <p>The hepatocytes swelling might be exhibited as a result of disturbances of membranes function that lead to massive influx of water and Na<sup>+ </sup>due to GNPs effects accompanied by leakage of lysosomal hydrolytic enzymes that lead to cytoplasmic degeneration and macromolecular crowding. Hydropic degeneration is a result of ion and fluid homestasis that lead to an increase of intracellular water. The vacuolated swelling of the cytoplasm of the hepatocytes of the GNPs treated rats might indicate acute and subacute liver injury induced by the GNPs. Binucleation represents a consequence of cell injury and is a sort of chromosomes hyperplasia which is usually seen in regenerating cells. The induced histological alterations might be an indication of injured hepatocytes due to GNPs toxicity that became unable to deal with the accumulated residues resulting from metabolic and structural disturbances caused by these NPs. These alterations were size-dependent with smaller ones induced the most effects and related with time exposure of GNPs. The appearance of hepatocytes cytoplasmic degeneration and nuclear destruction may suggest that GNPs interact with proteins and enzymes of the hepatic tissue interfering with the antioxidant defense mechanism and leading to reactive oxygen species (ROS) generation which in turn may induce stress in the hepatocytes to undergo atrophy and necrosis. More histomorphologcal, histochemical and ultrastrucural investigations are needed in relation of the application of GNPs with their potential role as a therapeutic and diagnostic tool.</p
Renal tissue alterations were size-dependent with smaller ones induced more effects and related with time exposure of gold nanoparticles
<p>Abstract</p> <p>Background</p> <p>Gold nanoparticles (GNPs) have important application for cell labeling and imaging, drug delivery, diagnostic and therapeutic purposes mainly in cancer. Nanoparticles (NPs) are being increasingly exploited for medical applications. The aim of the present study was to investigate the particle-size and period effects of administration of GNPs on the renal tissue in an attempt to address their potential toxicity.</p> <p>Methods</p> <p>A total of 70 healthy male Wistar-Kyoto rats were exposed to GNPs received 50 or 100 μl of GNPs infusion of size (10, 20 and 50 nm for 3 or 7 days) to investigate particle-size effect of GNPs on the renal tissue. Animals were randomly divided into groups, 6 GNPs-treated rats groups and one control group. Groups 1, 2 and 3 received infusion of 50 μl GNPs of size 10 nm (3 or 7 days), size 20 nm (3 or 7 days) and 50 nm (3 or 7 days), respectively; while groups 4, 5 and 6 received infusion of 100 μl GNPs of size 10 nm, size 20 nm and 50 nm, respectively. Stained sections of control and treated rats kidneys were examined for renal tissue alterations induced by GNPs.</p> <p>Results</p> <p>In comparison with respective control rats, exposure to GNPs doses has produced the following renal tubular alterations: cloudy swelling, vacuolar degeneration, hyaline droplets and casts, anisokaryosis, karopyknosis, karyorrhexis and karyolysis. The glomeruli showed moderate congestion with no hypercelluraity, mesangial proliferation or basement membrane thickening. The histological alterations were mainly seen in the cortex and the proximal renal convoluted tubules were more affected than the distal ones.</p> <p>Conclusions</p> <p>The induced histological alterations might be an indication of injured renal tubules due to GNPs toxicity that became unable to deal with the accumulated residues resulting from metabolic and structural disturbances caused by these NPs. The findings may suggest that GNPs interact with proteins and enzymes of the renal tissue interfering with the antioxidant defense mechanism and leading to reactive oxygen species (ROS) generation which in turn may induce stress in the renal cells to undergo atrophy and necrosis. The produced alterations were size-dependent with smaller ones induced more affects and related with time exposure of GNPs.</p
Uncovering true islam in Umm Zakiyyah’s trilogy "If I should speak"
This paper will give a detailed description of how Umm Zakiyyah’s trilogy correctly presents Islam in contrast to the misrepresentation of Islam in western literatur
Selfhood and otherness at the Wailing Wal
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1990.Includes bibliographical references (leaves 90-91).Few groups in the world have as long-standing a claim to "peoplehood" as do Jews. Despite the longevity of that claim, however, the problem of instability inherent in objectifying a collective identity has not yet been resolved. The existence and salience of a collective self is assumed at the same time that statements and actions within the group suggest that individuals are not sure of either the group's boundaries or its cultural content. The relationship between "Israeli society" and "the Jewish people" in Israel is loaded with tension, though there is little question in Israel or elsewhere that it is the "fact" of the latter that is responsible for the "fact" of the former. What about the conceptualization of the collective self in terms of a conceptualization of the collective "other"? The Israeli-Arab conflict is not a typical struggle between oppressor and oppressed, but is rather a struggle between stereotypes. When someone tells us who we are and has the power to impose their version of who we are on us -- according us certain rights and duties and denying us others by virtue of their representation of us -- we readily see it as an act of manipulation of the "facts" and the exercise of political power whose relation to reality we may question, even challenge. This analytical work is an attempt at examining some of the controversies generated by the dynamics and politics of manipulation as they structure in Israeli media in general. Architecture will be examined as a special representational medium that deals with signals of high symbolic values. In this endeavor, a recent Israeli project will be employed as an indicator of how architecture can become a viable channel of communication, where opposing groups can talk to each other, using this representational arena as a testing ground for new tendencies.by Sabri M. Jarrar.M.S
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