T. Magee - Academia.edu (original) (raw)
Papers by T. Magee
Journal of the Science of Food and Agriculture, 2004
McMinn, WA, Al-Muhtaseb, A. and Magee, TRA (2004), Assessment of two-and three-parameter Lewicki ... more McMinn, WA, Al-Muhtaseb, A. and Magee, TRA (2004), Assessment of two-and three-parameter Lewicki models for description of sorption phenomena of starch materials. Journal of the Science of Food and Agriculture, 84: 1695–1700. doi: 10.1002/jsfa. 1866
Food Research International, 2005
ABSTRACT
Journal of Food Engineering, 2004
ABSTRACT
Food and Bioproducts Processing, 2002
ABSTRACT
Adsorption and desorption isotherms for potato, highly amylopectin and highly amylose starch powd... more Adsorption and desorption isotherms for potato, highly amylopectin and highly amylose starch powders were determined at 30, 45 and 60°C using a gravimetric technique. Samples were equilibrated in desiccators containing sulphuric acid solutions of known water activity (0.05-0.95), and placed in temperature-controlled cabinets for approximately three weeks. The starch powders exhibited Type II behaviour. The sorption capacity decreased with increasing temperature. The data obtained were fitted to several models including two parameter relationships (Halsey, Oswin, Henderson, Modified-BET and Smith), three parameter equations (GAB, Ferro-Fontan) and four parameter equation (Peleg). A non-linear least square regression program was used to evaluate the models constants. The empirical Peleg model followed by the kinetic GAB and the semi empirical Ferro-Fontan models were found to best represent the experimental data in the water activity range 0.05-0.95. In the range of water activity 0.35-0.95 the Smith model was shown to give the closest fit to the experimental data.
Journal of Food Process Engineering, 2003
A thermodynamic approach was used to interpret the experimental adsorption anddesorption isothenn... more A thermodynamic approach was used to interpret the experimental adsorption anddesorption isothenn data forpotato starch gel. Cainrhtion of the thermodynamic properties (differential enthalpy, integral enthalpy. differential entropy and integral entropy) provides an understanding of the properties of water and energy requirements associated with the sorption behavior. Isosteric heats (differential enthalpies) were calcukated through direct use of moisture isotherms by applying the Clausius-Clapeyron equation. The differential enthalpy and entropy decreased with increasing moisture content and were adequately characterized by an exponential model. A plot of differential heat versus entropy satisfled the enthalpy-entropy compensaion theory. The spreading pressure increased with increasing water activity, and decreased with increasing temperature. The net integral enthalpy increased with moisture content to a maximum value (around the monolayer moisture content) and then decreased. In a reverse manner, the net integral entropy decreased with moisture content to a minimum value and then increased.
Radiology, 2003
To assess which postoperative patients benefit most from MR arthrography of the knee. One hundred... more To assess which postoperative patients benefit most from MR arthrography of the knee. One hundred consecutive MR arthrograms obtained in patients who had previous knee surgery underwent retrospective review in consensus by three radiologists after prospective reading by one of the three radiologists. Criterion on MR arthrograms for a retear was abnormal tracking of an intraarticular dilute gadolinium-based contrast material and saline mixture into the substance of a meniscus. Patients were separated into three groups: those with more than 25% meniscal resection, those with less than 25% meniscal resection, and those with meniscal repair. All 100 patients had preoperative MR images to review directly in conjunction with the postoperative MR images. Fifty-seven of these 100 patients underwent second-look arthroscopy. Nine patients had MR findings consistent with avascular necrosis. Nineteen patients had marked degenerative arthrosis in the area of previous surgery. Seven patients had chondral defects or injuries. Twenty-nine patients had clear MR evidence of a meniscal retear without any contrast material injected into the joint. In 32 of the 100 patients, intraarticular contrast material was useful in demonstrating a retear. Of these 32 patients, 22 had MR arthrographic evidence of a retear, while 10 had no clear MR arthrographic finding to explain postoperative pain. Four additional patients had no clear MR imaging or MR arthrographic abnormality. All patients with meniscal repair (n = 16) needed MR arthrography to diagnose a residual or recurrent meniscal tear. No patient with less than 25% meniscal resection (n = 23) needed MR arthrography to demonstrate a residual or recurrent meniscal tear. Sixteen of 61 patients with more than 25% meniscal resection needed MR arthrography to demonstrate a residual or recurrent meniscal tear. All patients with meniscal repair required MR arthrography. All patients with meniscal resection of more than 25%, who did not have severe degenerative arthrosis, chondral injuries, or avascular necrosis required MR arthrography. Patients with less than 25% meniscal resection did not need MR arthrography.
Biology of Reproduction, 1997
Erectile dysfunction is mainly due to the inability of the cavernosal smooth muscle of the penis ... more Erectile dysfunction is mainly due to the inability of the cavernosal smooth muscle of the penis to undergo complete relaxation. In the aging rat model, erectile dysfunction is accompanied by a reduction of penile smooth muscle compliance and, in very old animals, by a decrease in penile nitric oxide synthase (NOS), which is responsible for the synthesis of the mediator of penile erection, nitric oxide (NO). We have investigated whether the stimulation of penile NOS expression by local induction or gene therapy can mitigate erectile dysfunction in the aged rat. A mix of iNOS (inducible NOS) inducers was continuously delivered to the penises of 5-("adult"), 20-("old"), and 30-("very old") mo-old rats for 3-6 days, and the erectile response to electrical field stimulation of the cavernosal nerve was measured. The erectile dysfunction observed in old and very old rats as compared to adult animals was ameliorated by treatment with iNOS inducers. Penile iNOS was detectable in the penis of these rats by Western blot, NADPH diaphorase, and NOS activity assays. Inducible NOS was inducible in vitro in both rat and human corpora cavernosal tissue and in rat penile smooth muscle cells (RPSMC), as shown by Western blots. However, NO synthesis in cavernosal tissue upon iNOS protein induction remained low, indicating that the increased NOS levels were under physiological control. The iNOS cDNA was cloned from induced RPSMC mRNA and generated by reverse transcriptase polymerase chain reaction (RT-PCR) from induced human penile smooth muscle cells and corporal tissue. The coding regions from both the rat (RPiNOS) and human (HPiNOS) penile iNOS showed several amino acid differences from their analogous isoform in nonpenile tissues. RPiNOS cDNA injected into the penis mitigated the aging-associated erectile dysfunction. The iNOS construct was detected in cavernosal tissue by PCR, and its expression by RT-PCR and Western blots. These results open the way for the possible use of NOS isoforms in the management of erectile dysfunction.
Quality factors are those that determine the worth, or value, of a food product to the consumer. ... more Quality factors are those that determine the worth, or value, of a food product to the consumer. A thorough understanding of the factors affecting the quality of the product is thus of major relevance. With this in mind, the macro-structural properties (porosity, bulk and particle density) and physical changes (shrinkage) of cylindrical potato starch gel samples during convective drying were examined. Moisture removal was accompanied by the formation of a dense structure, with air temperature imparting a negligible influence. The system also exhibited a non-linear increase in particle density with decreasing moisture content. Drying, however, induced limited internal porosity development, i.e. ε < 10%. Volumetric shrinkage of the potato starch gel samples decreased almost linearly with moisture content.
Journal of the Science of Food and Agriculture, 2004
McMinn, WA, Al-Muhtaseb, A. and Magee, TRA (2004), Assessment of two-and three-parameter Lewicki ... more McMinn, WA, Al-Muhtaseb, A. and Magee, TRA (2004), Assessment of two-and three-parameter Lewicki models for description of sorption phenomena of starch materials. Journal of the Science of Food and Agriculture, 84: 1695–1700. doi: 10.1002/jsfa. 1866
Food Research International, 2005
ABSTRACT
Journal of Food Engineering, 2004
ABSTRACT
Food and Bioproducts Processing, 2002
ABSTRACT
Adsorption and desorption isotherms for potato, highly amylopectin and highly amylose starch powd... more Adsorption and desorption isotherms for potato, highly amylopectin and highly amylose starch powders were determined at 30, 45 and 60°C using a gravimetric technique. Samples were equilibrated in desiccators containing sulphuric acid solutions of known water activity (0.05-0.95), and placed in temperature-controlled cabinets for approximately three weeks. The starch powders exhibited Type II behaviour. The sorption capacity decreased with increasing temperature. The data obtained were fitted to several models including two parameter relationships (Halsey, Oswin, Henderson, Modified-BET and Smith), three parameter equations (GAB, Ferro-Fontan) and four parameter equation (Peleg). A non-linear least square regression program was used to evaluate the models constants. The empirical Peleg model followed by the kinetic GAB and the semi empirical Ferro-Fontan models were found to best represent the experimental data in the water activity range 0.05-0.95. In the range of water activity 0.35-0.95 the Smith model was shown to give the closest fit to the experimental data.
Journal of Food Process Engineering, 2003
A thermodynamic approach was used to interpret the experimental adsorption anddesorption isothenn... more A thermodynamic approach was used to interpret the experimental adsorption anddesorption isothenn data forpotato starch gel. Cainrhtion of the thermodynamic properties (differential enthalpy, integral enthalpy. differential entropy and integral entropy) provides an understanding of the properties of water and energy requirements associated with the sorption behavior. Isosteric heats (differential enthalpies) were calcukated through direct use of moisture isotherms by applying the Clausius-Clapeyron equation. The differential enthalpy and entropy decreased with increasing moisture content and were adequately characterized by an exponential model. A plot of differential heat versus entropy satisfled the enthalpy-entropy compensaion theory. The spreading pressure increased with increasing water activity, and decreased with increasing temperature. The net integral enthalpy increased with moisture content to a maximum value (around the monolayer moisture content) and then decreased. In a reverse manner, the net integral entropy decreased with moisture content to a minimum value and then increased.
Radiology, 2003
To assess which postoperative patients benefit most from MR arthrography of the knee. One hundred... more To assess which postoperative patients benefit most from MR arthrography of the knee. One hundred consecutive MR arthrograms obtained in patients who had previous knee surgery underwent retrospective review in consensus by three radiologists after prospective reading by one of the three radiologists. Criterion on MR arthrograms for a retear was abnormal tracking of an intraarticular dilute gadolinium-based contrast material and saline mixture into the substance of a meniscus. Patients were separated into three groups: those with more than 25% meniscal resection, those with less than 25% meniscal resection, and those with meniscal repair. All 100 patients had preoperative MR images to review directly in conjunction with the postoperative MR images. Fifty-seven of these 100 patients underwent second-look arthroscopy. Nine patients had MR findings consistent with avascular necrosis. Nineteen patients had marked degenerative arthrosis in the area of previous surgery. Seven patients had chondral defects or injuries. Twenty-nine patients had clear MR evidence of a meniscal retear without any contrast material injected into the joint. In 32 of the 100 patients, intraarticular contrast material was useful in demonstrating a retear. Of these 32 patients, 22 had MR arthrographic evidence of a retear, while 10 had no clear MR arthrographic finding to explain postoperative pain. Four additional patients had no clear MR imaging or MR arthrographic abnormality. All patients with meniscal repair (n = 16) needed MR arthrography to diagnose a residual or recurrent meniscal tear. No patient with less than 25% meniscal resection (n = 23) needed MR arthrography to demonstrate a residual or recurrent meniscal tear. Sixteen of 61 patients with more than 25% meniscal resection needed MR arthrography to demonstrate a residual or recurrent meniscal tear. All patients with meniscal repair required MR arthrography. All patients with meniscal resection of more than 25%, who did not have severe degenerative arthrosis, chondral injuries, or avascular necrosis required MR arthrography. Patients with less than 25% meniscal resection did not need MR arthrography.
Biology of Reproduction, 1997
Erectile dysfunction is mainly due to the inability of the cavernosal smooth muscle of the penis ... more Erectile dysfunction is mainly due to the inability of the cavernosal smooth muscle of the penis to undergo complete relaxation. In the aging rat model, erectile dysfunction is accompanied by a reduction of penile smooth muscle compliance and, in very old animals, by a decrease in penile nitric oxide synthase (NOS), which is responsible for the synthesis of the mediator of penile erection, nitric oxide (NO). We have investigated whether the stimulation of penile NOS expression by local induction or gene therapy can mitigate erectile dysfunction in the aged rat. A mix of iNOS (inducible NOS) inducers was continuously delivered to the penises of 5-("adult"), 20-("old"), and 30-("very old") mo-old rats for 3-6 days, and the erectile response to electrical field stimulation of the cavernosal nerve was measured. The erectile dysfunction observed in old and very old rats as compared to adult animals was ameliorated by treatment with iNOS inducers. Penile iNOS was detectable in the penis of these rats by Western blot, NADPH diaphorase, and NOS activity assays. Inducible NOS was inducible in vitro in both rat and human corpora cavernosal tissue and in rat penile smooth muscle cells (RPSMC), as shown by Western blots. However, NO synthesis in cavernosal tissue upon iNOS protein induction remained low, indicating that the increased NOS levels were under physiological control. The iNOS cDNA was cloned from induced RPSMC mRNA and generated by reverse transcriptase polymerase chain reaction (RT-PCR) from induced human penile smooth muscle cells and corporal tissue. The coding regions from both the rat (RPiNOS) and human (HPiNOS) penile iNOS showed several amino acid differences from their analogous isoform in nonpenile tissues. RPiNOS cDNA injected into the penis mitigated the aging-associated erectile dysfunction. The iNOS construct was detected in cavernosal tissue by PCR, and its expression by RT-PCR and Western blots. These results open the way for the possible use of NOS isoforms in the management of erectile dysfunction.
Quality factors are those that determine the worth, or value, of a food product to the consumer. ... more Quality factors are those that determine the worth, or value, of a food product to the consumer. A thorough understanding of the factors affecting the quality of the product is thus of major relevance. With this in mind, the macro-structural properties (porosity, bulk and particle density) and physical changes (shrinkage) of cylindrical potato starch gel samples during convective drying were examined. Moisture removal was accompanied by the formation of a dense structure, with air temperature imparting a negligible influence. The system also exhibited a non-linear increase in particle density with decreasing moisture content. Drying, however, induced limited internal porosity development, i.e. ε < 10%. Volumetric shrinkage of the potato starch gel samples decreased almost linearly with moisture content.