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Papers by Amr EL-Sadek

one of most economic , life-saving therapy in severely anemic cattle

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2011

Glow curve analysis is widely used for dosimetric studies and applications. Therefore, a new comp... more Glow curve analysis is widely used for dosimetric studies and applications. Therefore, a new computer program, GCAFIT, for deconvoluting first-order kinetics thermoluminescence (TL) glow curves and evaluating the activation energy for each glow peak in the glow curve has been developed using the MATLAB technical computing language. A non-linear function describing a single glow peak is fitted to experimental points using the Levenberg-Marquardt least-square method. The developed GCAFIT software was used to analyze the glow curves of TLD-100, TLD-600, and TLD-700 nanodosimeters. The activation energy E obtained by the developed GCAFIT software was compared with that obtained by the peak shape methods of Grossweiner, Lushchik, and Halperin-Braner. The frequency factor S for each glow peak was also calculated. The standard deviations are discussed in each case and compared with those of other investigators. The results show that GCAFIT is capable of accurately analyzing first-order TL glow curves. Unlike other software programs, the developed GCAFIT software does not require activation energy as an input datum; in contrast, activation energy for each glow peak is given in the output data. The resolution of the experimental glow curve influences the results obtained by the GCAFIT software; as the resolution increases, the results obtained by the GCAFIT software become more accurate. The values of activation energy obtained by the developed GCAFIT software a in good agreement with those obtained by the peak shape methods. The agreement with the Halperin-Braner and Lushchik methods is better than with that of Grossweiner. High E and S values for peak 5 were observed; we believe that these values are not real because peak 5 may in fact consist of two or three unresolved peaks. We therefore treated E and S for peak 5 as an effective activation energy, E eff, and an effective frequency factor, S eff . The temperature value for peak 5 was also treated as an effective quantity, T m eff .

Journal of environmental radioactivity, 2014

Can and Bare method is a widely used passive method for measuring the equilibrium factor F throug... more Can and Bare method is a widely used passive method for measuring the equilibrium factor F through the determination of the track density ratio between bare (D) and filtered (Do) detectors. The dimensions of the used diffusion chamber are altering the deposition ratios of Po-isotopes on the chamber walls as well as the ratios of the existing alpha emitters in air. Then the measured filtered track density and therefore the resultant equilibrium factor is changed according to the diffusion chamber dimensions. For this reason, high uncertainty was expected in the measured F using different diffusion chambers. In the present work, F is derived as a function of both track density ratio (D/Do) and the dimensions of the used diffusion chambers (its volume to the total internal surface area; V/A). The accuracy of the derived formula was verified using the black-box modeling technique via the MATLAB System identification toolbox. The results show that the uncertainty of the calculated F by u...

Thermoluminescence (TL) glow peaks were simulated over a wide range of absorbed doses using the i... more Thermoluminescence (TL) glow peaks were simulated over a wide range of absorbed doses using the interactive multipletrap system (IMTS) model. The absorbed dose range was divided into three regions; a region in which the measured TL signal grows quadratically with the absorbed dose, a supraquadratic dose-response region and dose-saturation region. The properties of the simulated glow peaks were investigated for each dose region. The different behaviors of the maximum peak position (T max ) with the absorbed doses were discussed. The applicability of applying the general-order kinetics (GOK), the mixed-order kinetics (MOK), and the developed one trap-one recombination (OTOR) center expressions on the IMTS glow peaks was investigated. The results showed that, in general, the developed OTOR expressions are the most apt expressions to be used in the peak-fitting method for the deconvolution of the experimental glow curves. The accuracy of the GOK and MOK expressions in describing the IMTS glow peaks is dependent on the value of the ratio of the trapping probability to the recombination probability (R ¼ A 1 /A m ) and the amount of the absorbed dose. New TL expressions based on the non-interactive multiple-trap system (NMTS) model were deduced.

The general-semi analytical thermoluminescence (TL) expressions based on the one trap-one recombi... more The general-semi analytical thermoluminescence (TL) expressions based on the one trap-one recombination center (OTOR) were developed to fit the single glow-peaks generated with exponential heating function (EHF) profile. The peak shape method (PSM) expressions based on the general-order kinetics (GOK) model were also developed for the glow-peaks generated with EHF profile. The success and failure of the GOK model in describing the glow-peaks generated with EHF was discussed. The new developed TL expressions were tested in the cases in which the other TL expressions based on the GOK model failed. The results showed that in the case of dose saturation and strong re-trapping probability, the error in the calculated activation energy (E) using the GOK model expressions exceeded 50%. While, using the new developed TL expressions, the error in the calculated E did not exceed 0.5%.

The accuracy of the thermoluminescence (TL) kinetics parameters obtained using the computerized g... more The accuracy of the thermoluminescence (TL) kinetics parameters obtained using the computerized glow curve deconvolution (CGCD) algorithm was tested. The differential equation governing the electron traffic in the one trap-one recombination (OTOR) level model was solved with almost no approximation using the Fehlberg-Runge-Kutta method. A set of simulated glow peaks was generated for a wide range of kinetics parameter values. These glow peaks were then fitted using the generalorder kinetics equation. Comparisons between the kinetics parameter values of the simulated glow peaks and those obtained by the CGCD method were made. The results show that the accuracy of the different kinetics parameters obtained by the CGCD method is not the same and that it varies according to the value of the kinetics order (b). The overlapping of two glow peaks with very close maximum peak positions (T ms ) results in a glow peak with unexpected values for the kinetics parameters. A set of different cases of overlapping glow peaks is also discussed.

Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine, Jan 11, 2014

The new developed thermoluminescence (TL) glow-peak expressions derived from the one trap-one rec... more The new developed thermoluminescence (TL) glow-peak expressions derived from the one trap-one recombination (OTOR) level model were used to analyze the TL glow-curves recorded with linear and exponential heating function profiles under various experimental conditions. The results showed that these expressions can, accurately, analyze the TL glow-curves even with the overlapped glow-peaks. Low values of R=An/Am were reported for glow-peaks in different TL materials. A glow-peak with the possibility of An>Am was also pointed out.

Journal of Luminescence, 2014

An overview of the successes and failure of the computerized glow curve deconvolution (CGCD) and ... more An overview of the successes and failure of the computerized glow curve deconvolution (CGCD) and the peak shape methods in describing the glow peaks generated from the fundamental one trap-one recombination center (OTOR) model was discussed. Also, the existing method, and a new developed one, to test the applicability of the existing thermoluminescence (TL) expressions to describe the glow peaks were discussed. The new TL expressions deduced by Kitis and Vlachos ([17] G. Kitis, N.D. Vlachos, Radiat. Meas. 48 were tested in the cases in which the other existing TL expressions failed. The results showed that the error in the calculated activation energy (E) using the existing expressions may reach up, in some cases, to 50%. While, using the new TL expressions, the error in the calculated E did not exceed 0.5%.

Liver Transplantation

AIMS: The purpose of this work was to study the role of surgery in the management of biliary comp... more AIMS: The purpose of this work was to study the role of surgery in the management of biliary complications in recipients after living donor liver transplantation. METHODS: A retrospective analysis that was done on recipients who underwent living donor liver transplantation at the National Liver Institute, Menoufia University from April 2003 to August 2012 (185 cases). RESULTS: Biliary complications occurred in 69 cases (37.3%). Bile leak was in 39 cases (21.1%) and biliary stricture was in 40 cases (21.6%). The first line treatment of biliary leak was conservative management in 23.1% while pigtail was placed in 76.9% of the cases with biliary leak. The condition resolved in 33.3% while 15.5% died receiving no further management. ERCP was done in 33.3% while surgical intervention was done in 17.9% of the cases as a second line treatment. Surgery was in the form of open drainage and external biliary diversion. The outcome of treatment of biliary leaks was recovery in 71.8% and mortali...

The liver is a common site of metastases. The most relevant metastatic tumor of the liver to the ... more The liver is a common site of metastases. The most relevant metastatic tumor of the liver to the surgeon is colorectal cancer because of the well-documented potential for long-term survival after complete resection. However, a large number of other tumors commonly metastasize to the liver, including cancers of the upper gastrointestinal system (stomach, pancreas, biliary), genitourinary system (renal, prostate), neuroendocrine system, breast, eye (melanoma), skin (melanoma), soft tissue (retroperitoneal sarcoma), and gynecologic system (ovarian, endometrial, cervix). The high frequency of liver metastases is caused by: 1. The liver's vast blood supply, which originates from portal and systemic systems. 2. The fenestrations of the hepatic sinusoidal endothelium may facilitate penetration of malignant cells into the hepatic parenchyma. 3. Humoral factors that promote cell growth and cellular factors, such as adhesion molecules, favor metastatic spread to the liver. 4. The liver&#3...

Egyptian Liver Journal, 2011

Risk factors for hypokalemia syndrome include the early lactation period, anorexia, and repeated ... more Risk factors for hypokalemia syndrome include the early lactation period, anorexia, and repeated administration of isoflupredone. Treatment includes basic supportive care for recumbent animals and aggressive potassium replacement therapy. Prognosis is guarded for recumbent cattle and worsens if hypokalemic myopathy or complications of recumbency occur.

Dairy cattle breeds ‫ﺍﻟﻔﻙ‬ ‫ﻓﻲ‬ ‫ﻟﻬﺎ‬ ‫ﻟﻴﺱ‬ ‫ﻤﺘﺴﺎﻗﻁﺔ،‬ ‫ﺠﻭﻓﺎﺀ‬ ‫ﻗﺭﻭﻥ‬ ‫ﺫﺍﺕ‬ ‫ﻤﺠﺘﺭﺓ‬ ‫ﺤﻴﻭﺍﻨﺎﺕ‬ ‫ﻜﻭ... more Dairy cattle breeds ‫ﺍﻟﻔﻙ‬ ‫ﻓﻲ‬ ‫ﻟﻬﺎ‬ ‫ﻟﻴﺱ‬ ‫ﻤﺘﺴﺎﻗﻁﺔ،‬ ‫ﺠﻭﻓﺎﺀ‬ ‫ﻗﺭﻭﻥ‬ ‫ﺫﺍﺕ‬ ‫ﻤﺠﺘﺭﺓ‬ ‫ﺤﻴﻭﺍﻨﺎﺕ‬ ‫ﻜﻭﻨﻬﺎ‬ ‫ﻓﻲ‬ ‫ﺍﻟﻤﺎﺸﻴﺔ‬ ‫ﺘﻤﺘﺎﺯ‬ ‫ﻭﺍﻨﻴﺎﺏ‬ ‫ﻗﻭﺍﻁﻊ‬ ‫ﺍﻟﻌﻠﻭﻱ‬ . ‫ﻭﺘﺤﻤل‬ ‫ﺍﺠﺯﺍﺀ‬ ‫ﺍﺭﺒﻌﺔ‬ ‫ﻤﻥ‬ ‫ﺍﻟﻤﻜﻭﻥ‬ ‫ﺍﻟﻀﺭﻉ‬ ‫ﺒﻭﺠﻭﺩ‬ ‫ﺍﻨﺎﺜﻬﺎ‬ ‫ﻭﺘﺘﺼﻑ‬ ‫ﻓﻠﻘﻴﺔ‬ ‫ﺒﻤﺸﻴﻤﺔ‬ ‫ﺍﻻﻡ‬ ‫ﺒﺭﺤﻡ‬ ‫ﻴﺘﺼل‬ ‫ﻭﺍﺤﺩﺍ‬ ‫ﺠﻨﻴﻨﺎ‬ ‫ﺍﻟﻌﺎﺩﺓ‬ ‫ﻓﻲ‬ . ‫ﻭ‬ ‫ﺒﻭﺱ‬ ‫ﺠﻨﺱ‬ ‫ﻴﺸﻤل‬ Bos ‫ﺃ‬ ‫ﺭﺒﻌﺔ‬ ‫ﻫﻲ‬ ‫ﺍﺠﻨﺎﺱ‬ ‫ﺘﺤﺕ‬ :

Milk fever (parturient paresis, hypocalcemia, paresis puerperalis, parturient apoplexy) is a nonf... more Milk fever (parturient paresis, hypocalcemia, paresis
puerperalis, parturient apoplexy) is a nonfebrile disease
of adult dairy cows and female goats caused by an
acute calcium deficiency. In dairy cows, hypocalcemia
causes progressive neuromuscular dysfunction with
flaccid paralysis, circulatory collapse, and depression
of consciousness. Hypocalcemia in goats causes varying
combinations of tetany and flaccid paralysis.
Although clinical cases of milk fever generally respond
well to treatment, the costs of this disease are very
high owing to clinical complications and milk production
losses. The pathogenesis of milk fever is complex,
and several prevention strategies have been proposed
to counter the metabolic disturbances that lead to
hypocalcemia.

The periparturient or transition period of 4 weeks before and 4 weeks after calving is characteri... more The periparturient or transition period of 4 weeks before and 4 weeks after calving is characterised by a greatly increased risk of disease.
Hypocalcaemia around calving is a risk factor for many of these diseases and is an indirect risk factor for increased culling. The
incidence of clinical hypocalcaemia (milk fever) in the field generally ranges from 0–10%, but may exceed 25% of cows calving. In
research trials conducted on milk fever the incidence has approached 80% of cows calving.
Homeostasis of calcium (Ca) is regulated by calcitonin, parathyroid hormone and 1,25(OH)2 vitamin D3. Age increases the risk of
milk fever by approximately 9% per lactation. Control of milk fever has revolved around stimulation of homeostatic mechanisms
through feeding a pre-calving diet low in Ca. More recently, the role of the dietary cation anion difference (DCAD) in the prevention
of Ca disorders has been examined, both by field research and meta-analysis. The most appropriate form of the DCAD equation has
been contentious, but recent meta-analyses have shown that the equation (Na++K+) (Cl + S2) is most effective for predicting milk
fever risk. Decreased risk of milk fever is linear with DCAD, whereas the effect of DCAD on urinary pH is curvilinear. A pivotal role of
providing dietary magnesium (Mg) before calving has been confirmed by meta-analysis, and a quadratic effect of Ca on milk fever risk
was found with a peak occurring with dietary levels of 1.1–1.3% of dry matter.
Risks of milk fever increase with increased dietary phosphorus (P) fed pre-calving and with increasing days of exposure to a pre-calving
diet. Meta-analysis has revealed that the important roles of dietary Ca, Mg and P, as well as the duration of exposure to the precalving
diet in milk fever control strategies are independent of DCAD. Studies on the effect of exposure to well designed pre-calving diets
have shown that substantial improvements in production, reproduction and animal health can be made but further examination of the
influence of the period of exposure to different diets is warranted.
2008 Elsevier Ltd. All rights reserved.

Thesis Chapters by Amr EL-Sadek

lameness is one of 3 affections in dairy farm following 1) mastitis 2)Reproductive failure Lamen... more lameness is one of 3 affections in dairy farm following

mastitis
2)Reproductive failure
Lameness is one of the most prevalent and costly of clinical disease conditions in dairy cattle