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81.
82.
A simulation study has been performed to quantify the effect of volume reduction on the thyroid absorbed dose per decay and to investigate the variation of energy deposition per decay due to β- and γ-activity of 131I with volume/mass of thyroid, for water, ICRP- and ICRU-soft tissue taken as thyroid material. A Monte Carlo model of the thyroid, in the Geant4 radiation transport simulation toolkit was constructed to compute the β- and γ-absorbed dose in the simulated thyroid phantom for various values of its volume. The effect of the size and shape of the thyroid on energy deposition per decay has also been studied by using spherical, ellipsoidal and cylindrical models for the thyroid and varying its volume in 1-25 cm3 range. The relative differences of Geant4 results for different models with each other and MCNP results lie well below 1.870%. The maximum relative difference among the Geant4 estimated results for water with ICRP and ICRU soft tissues is not more than 0.225%. S-values for ellipsoidal, spherical and cylindrical thyroid models were estimated and the relative difference with published results lies within 3.095%. The absorbed fraction values for beta particles show a good agreement with published values within 2.105% deviation. The Geant4 based simulation results of absorbed fractions for gammas again show a good agreement with the corresponding MCNP and EGS4 results (±6.667%) but have 29.032% higher values than that of MIRD calculated values. Consistent with previous studies, the reduction of the thyroid volume is found to have a substantial effect on the absorbed dose. Geant4 simulations confirm dose dependence on the volume/mass of thyroid in agreement with MCNP and EGS4 computed values but are substantially different from MIRD8 data. Therefore, inclusion of size/mass dependence is indicated for 131I radiotherapy of the thyroid. 相似文献
83.
Rehman Samiya Keefover-Ring Ken Haq Ihsan ul Dilshad Erum Khan Mohammad Imran Akhtar Nosheen Mirza Bushra 《Applied biochemistry and biotechnology》2019,188(3):893-895
Applied Biochemistry and Biotechnology - The original version of this article unfortunately contained a mistake in the image of Figure 1 and in Table 4. The corrected version of the figure... 相似文献
84.
Hai‐Qiao Wang Mirza Mačković Andres Osvet Ivan Litzov Elena Epelbaum Alfons Stiegelschmitt Miroslaw Batentschuk Erdmann Spiecker Christoph J. Brabec 《Particle & Particle Systems Characterization》2015,32(3):340-346
A new upconversion nanocrystal phase Yb2Mo4O15:Er is developed by using a facile aqueous‐precipitation procedure combined with thermal annealing. Nanocrystals of Yb2Mo4O15 are exclusively synthesized, with particle sizes ranging from 1 to 20 nm. The optical properties are characterized and a high upconversion quantum yield is determined to be ≈1.3% at room temperature, under excitation of ≈500 mW cm?2 IR (975 nm). To the best of our knowledge, this is the first work concerning the synthesis of nanocrystalline Yb2Mo4O15 and the characterization of its upconversion properties, which possesses the potential to be utilized in bio‐probing and thin‐film optoelectronic device applications. 相似文献
85.
Alexander Raith Philipp Altmann Mirza Cokoja Wolfgang A. Herrmann Fritz E. Kühn 《Coordination chemistry reviews》2010,254(5-6):608-634
An overview of η5,η1-coordinated transition metal ansa complexes is given. These compounds bear one or more coordinated cyclopentadienyl moieties connected with a η1-bridging σ-bonded carbon chain featuring a length of at least two carbon atoms. Synthetic approaches, as well as characterisation and applications are described. 相似文献
86.
Schröter MK Khodeir L van den Berg MW Hikov T Cokoja M Miao S Grünert W Muhler M Fischer RA 《Chemical communications (Cambridge, England)》2006,(23):2498-2500
Free-standing, ZnO surface decorated Cu nanoparticles of 1-3 nm size were obtained by sequential co-pyrolysis of [Cu(OCHMeCH2NMe2)2] and ZnEt2 in squalane in the absence of additional surfactants and proved to be highly active quasi homogeneous catalysts for methanol synthesis from CO and H2. 相似文献
87.
Nadira Ibri?imovi? Mirza Ibri?imovi? Margit Barth Ulrich Bohrn 《Monatshefte für Chemie / Chemical Monthly》2010,205(2):125-130
Abstract
Spoilage of products can mainly be attributed to microorganisms which “live on the product”, i.e. which are able to utilize and/or metabolize components and/or molecules of the product. The objective of this work was to develop and optimize sensor prototypes indicating the quality of a product “in real time”, i.e. at the time the consumer is looking at the product. The design of the presented sensors relates to optical phenomena, for example anomalous absorption and remission of light. The crucial point of the sensor prototypes is a layer sensitive to the analyte, a polymer degradable by enzymes produced by the respective microorganisms. After incubation of the sensor setup with contaminated products, the lytic enzymes released from decaying cell material change the thickness of the polymer layer and generate a colour change visible by the naked eye. Production of the sensor prototypes is very simple and inexpensive and they might be successfully integrated into product packaging. 相似文献88.
89.
Co‐administration of HMG‐CoA reductase with antidiabetic drugs is most common since antidiabetic drugs are mostly prescribed for long term therapy. In the present paper, we describe the simultaneous determination of antidiabetic (pioglitazone hydrochloride and gliquidone) in presence of statins (rosvastatin and simvastatin) in formulations and in human serum using RP‐HPLC technique. The serum samples were subjected to protein precipitation with acetonitrile prior to an HPLC analysis. At a flow rate of 1 mL·min−1 isocratic elution was employed, using mobile phase consisting of methanol/water (90:10, V:V), pH 3.50 with phosphoric acid and absorbance was recorded at 235 nm. The assay was reproducible, linear (concentration range of 5–50 μg·mL−1) and accurate. The LOD and LOQ values were 1.32, 0.28, 0.05 and 0.57 μg·mL−1 and 4.39, 0.93, 0.16 and 1.90 μg·mL−1 for pioglitazone hydrochloride, gliquidone, rosvastatin and simvastatin, respectively. There were no interfering peaks due to the excipients present in the pharmaceutical tablet and serum. Thus, the proposed method is simple and suitable for the analysis of active ingredient in tablet form and human serum. 相似文献
90.
Babur M. Mirza Adnan Saeed Safeer Sadiq 《International Journal of Theoretical Physics》2009,48(10):2938-2943
We investigate the effects of magnetic field on the background spacetime of a spherically symmetric relativistic star. Using
the general relativistic Maxwell equations coupled to the Einstein field equations for the gravitational field, it is shown
that not only the backreaction of the spacetime modifies the magnetic field of the star, but also the magnetic field of the
star molds the spacetime in its vicinity. The part played by the poloidal as well as the toroidal components of the magnetic
field on the exterior spacetime are investigated. 相似文献