10 research outputs found
Solâgel preparation and characterization of nano-crystalline lithiumâmica glassâceramic
The nano-crystalline lithiumâmica glassâceramic with separated crystallite size of 13 nm was prepared using solâgel technique. In such a process, the structural evolutions and microstructural characteristics of the synthesized samples were investigated through X-ray diffraction, transmission electron microscopy, thermal analysis and Fourier transform infrared spectroscopy. It was found that the crystallite size of the mica obtained from solâgel method is smaller than the one synthesized via conventional melted method. The XRD results also showed that the crystallization of mica occurred above 675 °C and it could originate from MgF2 so that the next stage will also be the transformation from mica to norbergite and norbergite to chondrodite. The activation energy of the crystallization and Avrami factor were measured as 376.7 kJ molâ1 and 2.3, respectively. It is found that the bulk crystallization could be considered as the predominant crystallization mechanism for the glassâceramic
The correlation between endothelin-1 antibody plasma concentrations in patients with scleroderma and different manifestations of the disease
Background: Systemic scleroderma (SSc) is a generalized connective tissue disorder of unknown origin which most notably is characterized by skin thickening and organ damage. Endothelin-1 (ET-1) antibody plays a role in skin fibrosis. The aim of this study was to determine the prevalence and correlation of different manifestations of SSc with ET-1 plasma levels. Methods: This cross-sectional analytical study was conducted on 95 patients (91 women and four men) with scleroderma in 2006. The patients had been referred to the Rheumatology Clinic of Shariati Hospital in Tehran, Iran. The demographic data and signs and symptoms were entered in a questionnaire and endothelin-1 concentrations were measured. Results: The mean age of the patients was 38+12.29 years. Diffuse cutaneous SSc (dcSSc) was diagnosed in 52 and limited cutaneous SSc (lcSSc) in 43 patients. Raynaud's phenomenon (91%) was the most common manifestation in the patients. The relationship between the resorption of terminal phalanges due to fibrosis with the plasma concentration of Endothelin-1 was statistically significant (p=0.001). Pitting ulcers had significant relationships with endothelin-1 concentrations too (p<0.05). No other significant relationships were found between the other manifestation of the disease and Endothelin-1 concentration. Conclusion: In this study, Reynaud's phenomenon was the most frequent sign in patients with scleroderma. Thus, it could serve as a tool for the diagnosis of scleroderma. As there were no significant relationships between the other manifestations of scleroderma with endothelin-1, a cohort study with a larger sample size is suggested
Fusion of Clostridium perfringens type D and B epsilon and beta toxin genes and itâs cloning in E. coli
Designing and producing a proper fusion construction is the most important problem of producing large quantities of a properly folded functional protein. This construction should have all necessary components of a real gene. A good designed fusion gene construction could be cloned into a good and suitable host. Clostridium perfringens is an important pathogen of humans and livestock and produces numerous toxins including epsilon and beta which are responsible for severe diseases. In the present study a new construction containing Clostridium perfringens type D epsilon toxin gene and type B beta toxin gene was designed. At the first step two pairs of primers were used for these genes amplification. At the next step epsilon forward and beta reveres primers were used to produce a chimeric gene containing amplified partial cds of etxD and partial cds of cpbB which are linked together by the AEAAAKEAAAKA fragment as a small linker. The method was based on fusion PCR and using of Pfu DNA polymerase, which has a proofreading activity. The fusion gene inserted into pJET1.2blunt and cloned into E.coli strain TOP10. Based on the latest information, this is the first design and cloning of epsilon-beta fusion gene and also this is the first time that PCR fusion strategy is used for Clostriadial gene fusion, which could be used for development of a recombinant epsilon-beta fusion protein vaccine. This construction also could serve as a model for development and production of novel fusion protein for other potential proteins and toxins
Involvement of PPAR receptors in the anticonvulsant effects of a cannabinoid agonist, WIN 55,212-2
Cannabinoid and PPAR receptors show well established interactions in a set of physiological effects. Regarding the seizure-modulating properties of both classes of receptors, the present study aimed to evaluate the roles of the PPAR-gamma, PPAR-alpha and CB1 receptors on the anticonvulsant effects of WIN 55,212-2 (WIN, a non selective cannabinoid agonist).The clonic seizure thresholds after intravenous administration of pentylenetetrazole (PTZ) were assessed in mice weighing 23-30. g.WIN increased the seizure threshold dose dependently. Pretreatment with pioglitazone, as a PPARĂÂł agonist, potentiated the anticonvulsant effects of WIN, while PPARĂÂł antagonist inhibited these anticonvulsant effects partially. On the other hand PPARñ antagonist reduced the anticonvulsant effects of WIN significantly. Finally the combination of CB1 antagonist and PPARñ antagonist could completely block the anticonvulsant properties of WIN.Taken together, these results show for the first time that a functional interaction exists between cannabinoid and PPAR receptors in the modulation of seizure susceptibility. Ă© 2014
Evaluation of different attractive traps for capturing sand flies (diptera: Psychodidae) in an endemic area of leishmaniasis, Southeast of Iran
Background: The attraction of phlebotomine sand flies to plant and animal hosts is due to the produced chemical compounds, affecting the olfactory receptors of the insects. Therefore, novel and effective methods, such as Attractive Toxic Sugar Baits (ATSB) and Attractive Toxic Baits (ATB), are based on the effective materials that attract sand flies toward the host. The present study was designed to identify the attractive materials in plants and animals for using in ATSB and ATB. Methods: This cross-sectional study was carried out in July 2018 on endemic areas of leishmaniasis in Iran. Different baits, including mango, nectarine, grape, banana, melon and watermelon, defibrinated blood of cattle, sheep, goat and chicken, urine of cattle, sheep, goat and ultimately, simple and complex chemicals, such as CO2, 1-octanol, lactic acid and human sweat were placed inside the traps, and the rate of the sand flies attraction to these materials was studied. Furthermore, data were analyzed using the Kruskal-Wallis test and Mann Whitney U test. Results: There was a significant difference in the sand flies attraction between the traps containing watermelon, urine of cattle, and sheep, and chemicals such as CO2 and human sweat and the control trap (p< 0.05). Conclusion: This study showed that watermelon and CO2 are the potential candidates for using in ATSB and ATB, respectively. Ă© 2020 Tehran University of Medical Sciences. All rights reserved
Stability and size-dependency of CauchyâBorn hypothesis in three-dimensional applications
The GERDA experiment: status and perspectives
The GERDA experiment is located in the underground Gran Sasso laboratory. The experiment aims at studying the neutrinoless ÎČÎČ decay of 76Ge. The implementation of the experiment is divided in two consecutive phases. Phase I will allow within one year of data taking to reach a sensitivity limit for the half life of the process of the order of 2.5Ă1025 years. Phase II, with an increased amount of active material and a background index lower by one order of magnitude than in Phase I, will allow to reach a half life limit of about 1.5Ă1026 years. In the present paper a brief review of the status of the experiment and its perspectives is given.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard
An Overview of Solid Supported Palladium and Nickel Catalysts for C-C Cross Coupling Reactions
Observation of Gravitational Waves from the Coalescence of a Compact Object and a Neutron Star
International audienceWe report the observation of a coalescing compact binary with component masses and (all measurements quoted at the 90% credible level). The gravitational-wave signal GW230529_181500 was observed during the fourth observing run of the LIGO-Virgo-KAGRA detector network on 2023 May 29 by the LIGO Livingston Observatory. The primary component of the source has a mass less than at 99% credibility. We cannot definitively determine from gravitational-wave data alone whether either component of the source is a neutron star or a black hole. However, given existing estimates of the maximum neutron star mass, we find the most probable interpretation of the source to be the coalescence of a neutron star with a black hole that has a mass between the most massive neutron stars and the least massive black holes observed in the Galaxy. We estimate a merger rate density of for compact binary coalescences with properties similar to the source of GW230529_181500; assuming that the source is a neutron star-black hole merger, GW230529_181500-like sources constitute about 60% of the total merger rate inferred for neutron star-black hole coalescences. The discovery of this system implies an increase in the expected rate of neutron star-black hole mergers with electromagnetic counterparts and provides further evidence for compact objects existing within the purported lower mass gap