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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Characterization of an important drug binding site of human serum albumin /

Sollenne, Nicholas Peter January 1980 (has links)
No description available.
82

Palatability and Efficacy of Electrolyte Chews in Horses

Handlos, Grace 01 May 2023 (has links) (PDF)
The use of electrolytes in horses has become common in the equine community. Proper management of the equine athlete encourages the supplementation of electrolytes, especially during exercise. Electrolyte imbalance can cause physiological issues including fatigue, irregular heartbeat, cramping, and more. Electrolyte supplementation is utilized to replace losses via the sweat, urine, and defecation. Commercially available oral electrolyte forms include paste, powder, and pellets. Work describing chewable electrolyte use in horses has not been published. The objective of this work is two-fold: to determine preference across four electrolyte chew flavors and to ascertain efficacy of a novel electrolyte product. Protocol approval (#21-029) by Southern Illinois University Institutional Animal Care and Use Committee was obtained prior to initiation of this work. The study was completed in two phases. The first phase examined the palatability of the novel electrolyte chew while the second phase tested the serological effect of the product in exercising horses. In the first phase, stock-type horses (n = 10) were utilized for individual preference testing in palatability stocks over six days. During the palatability session, each horse was permitted 30 seconds to olfactorily investigate the product prior to release for consumption. Immediately following the olfactory period, each horse was allowed up to 5 minutes to voluntarily consume the electrolyte chews. Horses were presented with four treatments (A, B, C, D) on an alternating basis, with two treatments offered side-by-side per day. Treatment formulations consisted of the same base electrolyte content with varying flavors of peppermint, salt, and orchard grass (Table 2). Treatment locations were switched daily to prevent bias associated with location. Variables of interest included number of chews consumed (TI), first action (FA), first choice (FC), time spent consuming (TC) and water consumption (WC) were recorded. Bodyweight (BW) and body condition scores (BCS) were recorded twice over the study duration. Data were analyzed via numerical and categorical methods using PROC GENMOD, PROC FREQ & PROC GLM of SAS (v. 9.5). Significance was set at P < 0.05. There was no significant overall preference for any of the treatment formulations examined. However, there was a significant difference in chew consumption between days 1 and 2 (P = 0.0204). There was also a highly significant treatment effect between days 5 and 6 (P < 0.0001). The relationship between individual horse and consumption was variable and highly significant (P < 0.0001). The mean acceptance rate of the product was 63.6%. These results indicate palatability may differ significantly across horses for the flavors examined. In the second study phase, privately-owned local foxhunting horses (n = 15) were utilized in an exercise study. Due to poor consumption, nine horses were selected for use in the experiment to test treatments. There were three treatment groups: control (CON) offered no supplementation, light (LIG) consumed 6-9 chews, and moderate (MOD) voluntarily consumed 15-20 chews. Baseline jugular venipuncture and vitals assessments were completed on all horses prior to supplementation. Supplementation was offered in two parts: 30 minutes pre-ride and immediately following a 2-hour foxhunt ride in the afternoon. Afternoon temperature was 52°F with mostly sunshine and approximately 42% humidity. Upon return, horses were immediately offered electrolyte supplementation. Venipuncture and vitals assessments were repeated 30 minutes post-ride. Variables recorded were serum values (Na, K, Cl, Ca, HCO−3, Mg), chew consumption (TI), age, respiratory rate (RR), skin turgor (SKN), rectal temperature (BT), distance travelled (DIS) and average speed (SPD). Categorical variables were body condition score (BCS), sex, breed (BRD), and sweat rating (SWR). Data was analyzed via PROC GLM, PROC FREQ and PROC REG dependent on test with SAS (v. 9.5). Significance for all tests was set at P < 0.05. Serological values were unaffected by electrolyte consumption (P > 0.05). Body temperature was significantly higher for all horses following exercise, regardless of treatment group (P = 0.0005). Skin turgor showed significantly more time before return to original state during post-ride evaluation (P = 0.0013). Directional serum changes between Cl and K were significantly correlated (P = 0.0227) as well as Mg and Cl (P = 0.0316). Correlations of relational change between Ca and HCO−3 in addition to Ca and Na were approaching significance (P = 0.0707; P = 0.0800). Mares demonstrated a greater ability to maintain lower post-ride serum calcium levels than geldings (P = 0.013). The effect of breed on serological calcium change may also be considered (P = 0.0312). These results suggest that several major contributive factors require further investigation for the successful implementation of oral electrolyte chews into equine exercise regimens.
83

Ischaemic skeletal muscle increases serum ischaemia modified albumin.

Troxler, M., Thompson, D., Homer-Vanniasinkam, Shervanthi 02 November 2009 (has links)
No / Objectives Ischaemia modified albumin (IMA) has been used as a marker of myocardial ischaemia but little is known about its production during ischaemia of other tissues. The clinical models of patients with intermittent claudication and major arterial surgery were used to investigate IMA production from ischaemic skeletal muscle. Materials and methods IMA was measured pre-operatively, at end ischaemia, and 5min, 4, 24, 48, 72 and 144h post-surgery in patients undergoing (a) revascularisation for intermittent claudication (IC, n=15), (b) abdominal aortic aneurysm repair (AAA, n=12) and controls (n=16). Results The median pre-operative IMA concentration in IC patients was significantly higher than the AAA group (88.3 versus 83.5U/ml, p=0.036) and controls (88.3 versus 80.3U/ml, p=0.031). IMA concentrations increased significantly during arterial clamping in both IC and AAA groups (88.3 versus 120.0U/ml, p=0.001; 83.5 versus 118.8U/ml, p=0.002, respectively) consistent with increased skeletal muscle ischaemia. In contrast, there was only a mild perioperative increase in the controls (80.3 versus 91.6U/ml, p=0.012). Conclusions Patients with intermittent claudication have significantly elevated IMA and skeletal muscle ischaemia during arterial surgery results in significantly increased circulating IMA. When IMA is used to detect myocardial ischaemia, ischaemic skeletal muscle must be excluded.
84

Age-related Differences in Survival of AKR/J Mice Treated With Anti-Lymphocyte Globulins, Anti-Thymocyte Globulins, and Rabbit Anti-Mouse Brain Serum

Senn, Donald E. 05 1900 (has links)
This investigation was designed to study the age-related differences in the survival rates of 2-to 3- and 6- to 7-month-old AKR/J mice after continuous treatment with anti-lymphocyte globulins (ALG), anti-thymocyte globulins (ATG), or rabbit anti-mouse brain serum (RAMB).
85

Characterization by optical methods of the heat denaturation of bovine serum albumin (BSA) as affected by protein concentration, pH, ionic strength and sugar concentration

Kongraksawech, Teepakorn 14 March 2007 (has links)
The thermal denaturation of proteins has been extensively studied using several methods including differential scanning calorimetry (DSC). A custom-built optical system was used to study thermal effects on protein as an alternative method to DSC measurements. It was used to investigate the thermal stability of bovine serum albumin (BSA) with a focus on comparisons with published DSC data. In the first study, the effect of protein concentration on the thermal denaturation (Td) of BSA was determined and validated using published DSC data for bovine serum albumin (BSA). The optical rotation (OR) and transmitted light (TL) signals indicating protein conformational changes and gel formation, respectively, were collected during the heating of BSA solutions at ~6��C/min from room temperature to ~85��C. The experiments were performed on 1, 2.5 and 5% (w/v) BSA in 0.01 M phosphate buffer at pH 7 and ionic strength (IS) 0.08. BSA���s Td values obtained from this investigation were consistent with published values and had low experimental variability (CV<2.5%). In agreement with some but not all published data, increasing BSA concentration did not affect its thermal stability. Protein gel formation, however, increased with protein concentration. In the second study, changes in the OR and TL signal of BSA in 0.01 M phosphate buffer at pH 6.1, 7 and 7.9 with IS maintained at 0.04, 0.08 and 0.16 were recorded during the heating of BSA solutions at ~6��C/min from room temperature to ~85��C. BSA showed a maximum and minimum thermostability at pH 7 and 7.9, respectively, consistent with published values determined by DSC. BSA formed opaque gel at pH 6.1 approaching the BSA���s pI values. Increasing IS level did not have a significant effect on BSA���s Td value but promoted gel formation. In the third study, the optical method was applied to investigate the heat stability of BSA as affected by low concentrations of sucrose, trehalose or sorbitol. BSA solutions (2.5% w/v) in the presence of 0 5% sucrose, trehalose and sorbitol were heated at ~6��C/min from ambient temperature to ~85��C. In contrast with published work on the thermal stability of BSA in the presence of higher sugar concentrations, this study showed that increasing sugar concentration did not enhance the thermal stability of this protein. Also, the ability to promote protein stability among sucrose, trehalose and sorbitol were not significantly different. The significance of these studies is that they demonstrate that the custom-built optical methods here developed can be used to study heat-induced protein denaturation and the effect of environmental conditions. Future studies will examine other proteins such as ��-lactoglobulin or ��-lacactalbumin. A further advantage of optical systems is their ability to conduct real-time measurements which could be used for food processing control. / Graduation date: 2007
86

In vitro activation and enzyme kinetic analysis of recombinant midgut serine proteases from the Dengue vector mosquito Aedes aegypti

Rascon, Alberto, Gearin, Johnathon, Isoe, Jun, Miesfeld, Roger January 2011 (has links)
BACKGROUND:The major Dengue virus vector Aedes aegypti requires nutrients obtained from blood meal proteins to complete the gonotrophic cycle. Although bioinformatic analyses of Ae. aegypti midgut serine proteases have provided evolutionary insights, very little is known about the biochemical activity of these digestive enzymes.RESULTS:We used peptide specific antibodies to show that midgut serine proteases are expressed as zymogen precursors, which are cleaved to the mature form after blood feeding. Since midgut protein levels are insufficient to purify active proteases directly from blood fed mosquitoes, we engineered recombinant proteins encoding a heterologous enterokinase cleavage site to permit generation of the bona fide mature form of four midgut serine proteases (AaET, AaLT, AaSPVI, AaSPVII) for enzyme kinetic analysis. Cleavage of the chromogenic trypsin substrate BApNA showed that AaET has a catalytic efficiency (kcat/KM) that is ~30 times higher than bovine trypsin, and ~2-3 times higher than AaSPVI and AaSPVII, however, AaLT does not cleave BApNA. To measure the enzyme activities of the mosquito midgut proteases using natural substrates, we developed a quantitative cleavage assay based on cleavage of albumin and hemoglobin proteins. These studies revealed that the recombinant AaLT enzyme was indeed catalytically active, and cleaved albumin and hemoglobin with equivalent efficiency to that of AaET, AaSPVI, and AaSPVII. Structural modeling of the AaLT and AaSPVI mature forms indicated that AaLT is most similar to serine collagenases, whereas AaSPVI appears to be a classic trypsin.CONCLUSIONS:These data show that in vitro activation of recombinant serine proteases containing a heterologous enterokinase cleavage site can be used to investigate enzyme kinetics and substrate cleavage properties of biologically important mosquito proteases.
87

Developing a better buttermilk solution

Ireland, Elizabeth Rosa January 2014 (has links)
This document is a project document based on finding a more economical way to use buttermilk at Synlait Milk Ltd. Buttermilk is a by-product from the Anhydrous Milk Fat (AMF), which is the concentration of cream. It is a problem for many dairy companies in New Zealand, including Synlait. the problems arise due to the opportunity cost of using it. It is a low value product, but made in substantial quantities at a ratio of 55% buttermilk to 45% AMF. This feasibility study contains an analysis on buttermilk at Synlait, including opportunity costs and benefits with processing buttermilk into buttermilk powder. It provides insight into the feasibility of implementing a ‘washed cream’ process at Synlait which would provide an alternative method for using buttermilk. The feasibility of separating buttermilk components for separate use is also examined. Overall, this project provides a more economical solution for buttermilk use at Synlait Milk Ltd.
88

The aetiopathogenesis of ovarian hyperstimulation syndrome in women undergoing assisted conception

Singh Mathur, Rajneesh January 2000 (has links)
No description available.
89

STUDY AND CHARACTERIZATION OF DUAL-FUNCTION AFFINITY CHROMATOGRAPHIC ADSORBENTS HAVING SIZE EXCLUSION AND ADSORPTION PROPERTIES TO ISOLATE, PURIFY AND RECOVER SMALL BIOMOLECULES FROM COMPLEX BIOLOGICAL MIXTURES

Gonzalez Ortega, Omar January 2010 (has links)
In this work, the main emphasis of the research concerns the development of isolation and purification methods of biomolecules from biological fluids. Several separation techniques were incorporated in chromatographic gels to obtain multifunctional hybrid chromatographic separation media for proteins, peptides and amino acid isolation and purification.In the first part of the research, several chelating agents were synthesized and their effectiveness to purify immunoglobulins using Immobilized Metal Affinity Chromatography (IMAC) was investigated. Ethylenediamine triacetic acid (TED) with immobilized copper resulted in the most effective in terms of purification and protein capacities.The next part of the work involved the development of hybrid chromatographic media that combines protein specific adsorption with sharp controlled size access permeation. This was accomplished by incorporating two types of ligand derivatives, one that permits the permeation of only certain molecular size range compounds, and a second one that specifically binds target biomolecules among the compounds of that specific molecular size range. Hybrid systems included binding ligands for Immobilized Metal Affinity Chromatography (IMAC), Ion Exchange Chromatography (IEX) and Hydrophobic Interaction Chromatography (HIC) combined with a controlled access polymer at different densities such as polyethylene glycol (PEG) and dextran derivatives. In general, low grafting density of high molecular weight PEG was found to be as effective as high grafting density of low molecular weight PEG in the rejecting properties of the semi-permeable synthesized media.Theoretical and experimental batch adsorption studies were also performed with the hybrid media and a mathematical model was developed to study the uptake of proteins under specific conditions of controlled permeation.In the last stage of this work, chelating surfactants were synthesized and used as reversible affinity ligands on reversed phase adsorbents for protein separations.One of the main accomplishments of this research was the development of separation media for small molecular size compounds from larger molecules and from complex biological systems. Applications of special interest will include the isolation and purification of solutes, such as metal ions, toxins, drugs, biomolecules, including proteins, biotoxins, nucleic acids, peptides, hormones, and biomarkers from biological fluids (such as human serum, urine, etc.) and from aqueous solutions.
90

Characterisation of the kinetics of a putative macrophage scavenger receptor for the recognition and removal of advanced glycosylation end-products

Shaw, Sean Martin January 1994 (has links)
No description available.

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