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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.
201

Vápenato-hlinité hydráty - laboratorní příprava a charakterizace / Calcium aluminate hydrates - laboratory preparation and characterisation

Koplík, Jan January 2008 (has links)
Calcium aluminate phases are important parts of Ordinary Portland cement and Alumina cement. Various calcium aluminate hydrates originate during the hydration of calcium alumina phases. Their origin depends on the conditions of hydration. In the diploma thesis was investigated hydration of four calcium aluminate phases – CA, CA2, C12A7, C3A under the conditions of four pH – 6, 9, 11, 12,65. Calcium aluminate phases were prepared from CaCO3 and Al2O3 by clinkering in solid phase in laboratory oven. The phases were hydrated for 48 hours. Kinetics of the hydration was investigated by calorimetry. Calcium aluminate hydrates were identified by XRD and DTA.
202

Machine learning applications for measuring pH using CEST MRI

Icke, Ilknur 10 October 2019 (has links)
Non-invasive measurement of pH provides multiple potential benefits in oncology such as better identifying the type of drug that can be more effective in chemotherapy, potentially identifying tumors that are more likely to metastasize and also better assessing the treatment effects. Chemical Exchange Saturation Transfer (CEST) Magnetic Resonance Imaging (MRI) is a versatile non-invasive technique for molecular imaging. AcidoCEST MRI techniques have been developed over the recent years to perform tumor pH measurements by utilizing a contrast agent for which chemical exchange saturation transfer effects depend on the pH of the microenvironment. Quantitative description of CEST MRI signals are generally done via modeling Bloch-McConnell equations by incorporating pH as a parameter or by fitting Lorentzian line shapes to observed z-spectra and then computing a log ratio of the CEST effects from multiple labile protons of the same molecule (ratiometric method). Modeling using Bloch-McConnell equations is complicated and requires careful inclusion of many scan parameters to infer pH. The ratiometric method requires contrast agents that have multiple labile protons, thus making it unsuitable to use for molecules with a single labile proton. Furthermore, depending on the pH, sometimes it might not be possible to numerically compute the ratio due to the inability of detecting signal peaks for certain labile protons. Our aim here is to develop a machine learning based method that learns the CEST signal patterns from observed z-spectra on temperature and concentration-controlled contrast agent phantoms independent of the type of the contrast agent. Our results indicate that the machine learning method provides more general and accurate prediction of pH in comparison to the ratiometric method based on the phantom CEST dataset. Our method is more general in the sense that it does not require explicit modeling of signal peaks that are dependent on the type of contrast agent. We also describe a state of the art variational autoencoder based algorithm extending our machine learning method to measure tumor pH in vivo using AcidoCEST MRI on mouse tumor models.
203

Hodnocení výrobku z chmelových výhonků

Heinereichová, Iva January 2018 (has links)
The diploma thesis deals with sensory assessment, measurement of color and pH of six batches of hop shoots, which differ harvest days and pasteurization, dipping in water overnight and repeated pasteurization. Young shoots of hops were harvested during April. It is a pasteurized product from sweet-sour pickled hop shoots. Results of sensory assessment of hop shoots showed between batches a statistically significant difference (P <0,05) in a number of descriptors. Results of sweet-sour pickle did not showed differences between batches. The difference between batches was only for the purity descriptor. The term of harvest shoots may affect the sensory quality of hop shoots. Dipping of shoots overnight in water and the long-term effect of the pasteurisation temperature worsened the texture and color of the shoots.
204

Vliv vápnění půdy na výnos a kvalitu zrna kukuřice

Šimek, Vojtěch January 2018 (has links)
Master thesis on topic Influence of liming on yield and quality of corn grain was evaluating yield-making and qualitative parameters of grain maize KWS 9361 in two different variants of fertilizing depending on soil pH treatment with dolomitic limestone in comparison with control variants (without dolomitic limestone). One of these variants was fertilizing with only N rates 110kg N/ha and second of them was fertilizing with NPK fertilizer rates 110 kg N/ha, 50kg P/ha in P2O5 form and 125 kg K/ha in K2O form. No-liming variant fertilized with NPK did significantly have highest yield in all three years (in average 12,07 t/ha). As well the weight of thousand kernel was highest in no-liming variant with NPK fertilizer (average 299 g). Starch content has not been influenced by variants of fertilizing or liming, it has been influenced only by year. Content of crude proteins in grain has been highest in no-liming variant fertilized only with nitrogen (average 7,3 %).
205

Eliminace obsahu kadmia v máku aplikací saturačních kalů

Šebestová, Andrea January 2019 (has links)
The aim of the diploma thesis was to test the effect of the soil application of carbonation mud on the change of cadmium (Cd) content in soil and plants in the early stages of development. The experiment was based on a precise phytotron pot trial with a defined light, temperature and humidity regime. As the experimental plant, poppy (Papaver somniferum L., variety Major), was used. Silt brown soil was used for experimental vessels. The effect of carbonation mud was evaluated at the level of three variants of applied doses corresponding to 0, 5 and 10 t.ha-1. Cadmium [Cd (NO3)2] was applied in three variants: 1, 5 and 10 mg.kg-1 of soil. The parameters (soil pH, Cd content in the soil, plant weight, Cd content in the plant, Cd plant uptake) were analyzed in three terms during the experiment. From the results of the analyzes it was found that the control soil variant (6.78) and the cadmium variant without carbonation mud (6.87 - 6.88) showed the lowest soil pH. The highest soil pH was observed in variants with the highest doses of applied carbonation mud (7.64 - 7.66). With increasing doses of applied carbonation mud, the available cadmium content in the soil decreased significantly. A positive relationship of higher doses of carbonation mud and dry weight of plants was demonstrated. Plants with the highest dose of carbonation mud achieved the highest average weight. However, this effect was not proven statistically until the last sampling. Also, the content of cadmium in plants, as well as the plants cadmium uptake, was dependent on the doses of carbonation mud. The highest effect on the elimination of cadmium uptake by the plant was found in variants with the highest doses of carbonation mud.
206

Modulation of Cupric Ion Activity by pH and Fulvic Acid as Determinants of Toxicity in Xenopus Laevis Embryos and Larvae

Buchwalter, David B., Linder, Greg, Curtis, Lawrence R. 01 April 1996 (has links)
An ion-specific electrode measured cupric ion activity modulated by fulvic acid (FA) and pH in a series of modified Frog Embryo Teratogenesis Assay- Xenopus (FETAX) toxicity assays. Hydrogen ion concentration was the primary determinant of cupric ion activity, while FA played a smaller but significant role. Fulvic acid was a weak copper complexing agent at pH 5.50. At pH 5.50 there was slight reduction of ionic activity and a subsequent attenuation of copper toxicity with 5.0 mg/L FA. At pH 7.50, FA also had a mild attenuating effect on copper toxicity. At pH 6.50, copper was strongly complexed by FA at total copper (TCu) concentrations below its pH-dependent solubility limit. At TCu concentrations above the solubility limit FA enhanced toxicity. There was more cupric ion activity measured in the presence of 0.5 and 5.0 mg/L FA than without it at TCu concentrations above the solubility limit. The proposed mechanism for this behavior was FA action as a nucleation inhibitor. Under the chemical conditions of the pH 6.50 experiments, a stable supersaturation of copper was formed, resulting in a more toxic aqueous matrix.
207

Liposomal Coencapsulation of Doxorubicin with Listeriolysin O Increases Potency via Subcellular Targeting

Walls, Zachary F., Gong, Henry, Wilson, Rebecca J. 07 March 2016 (has links)
Liposomal doxorubicin is a clinically important drug formulation indicated for the treatment of several different forms of cancer. For doxorubicin to exert a therapeutic effect, it must gain access to the nucleus. However, a large proportion of the liposomal doxorubicin dose fails to work because it is sequestered within endolysosomal organelles following endocytosis of the liposomes due to the phenomenon of ion trapping. Listeriolysin O (LLO) is a pore-forming protein that can provide a mechanism for endosomal escape. The present study demonstrates that liposomal coencapsulation of doxorubicin with LLO enables a significantly larger percentage of the dose to colocalize with the nucleus compared to liposomes containing doxorubicin alone. The change in intracellular distribution resulted in a significantly more potent formulation of liposomal doxorubicin as demonstrated in both the ovarian carcinoma cell line A2780 and its doxorubicin-resistant derivative A2780ADR.
208

The Effect of Various Levels of Bicarbonate, Phosphorus, and pH on the Translocation of Iron in Plants

Doney, Ronald Conrad 01 May 1959 (has links)
Line-induced chlorosis is a nutritional disease affecting many fruit trees, berries, ornamental shrubs, and flowers in Utah and the western United States. In fact, this disease is of wide distribution on calcareous soils throughout the world. Lime-induced chlorosis has contributed to untold economic loss and has challenged the technical ingenuity of plant and soil scientists throughout the world. As yet the exact cause of chlorosis has not been determined; consequently, no permanent cures have been found.
209

Electrochemical Determination of PH using Paper-Based Devices

Metangmo, Armelle 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / For the past decade, many microfluidic paper-based analytical devices have been developed and used in different research fields. These devices are low-cost, portable, flexible, sterilizable, disposable, and easy to manufacture. The microfluidic paper-based analytical devices offer good alternatives to measurements and assays commonly performed in laboratories for analytical and clinical purposes, especially in diagnostics. In this work, we developed an electrochemical paper-based pH sensor. The determination of pH is essential in applications in areas as diverse as in the food industry, agriculture, health care or water treatment. The method presented in this work is an electroanalytical method that involves quantification of pH using stencil-painted graphite electrodes. Preliminary tests showed that pH can be determined on paper-based devices, thus indicating the presence of electroactive elements sensitive to pH on the surface of our electrodes (Chapter 4). Chemical modification of the electrode by adsorption with sodium carbonate and modification of the surface of the electrode was accomplished via: oxygen (ambient air) plasma treatment and pure oxygen plasma treatment. These treatments were to attempt to improve the definition of redox peaks on the CVs (Chapter 5). The changes made to the design of the paper-based device and the addition of a conditioning step improved the definition of the redox peaks on the CVs and increased the pH-sensing ability of our method (Chapter 6). The pH-sensing ability of our method was evaluated by testing solutions over a wide pH range. Adding sodium chloride to samples adjust the solution for accurate pH determination. The pH was successfully measured for solutions with values ranging from 1 to 13 and for artificial saliva samples prepared with pH values in the cavity-prone range (Chapter 7). This work offers a method that uses electroactive elements sensitive to pH on the surface of the PBD electrodes for pH-sensing.
210

Application of Proteomics in Understanding Pale Soft and Exudative Condition in Broiler Breast Meat

Desai, Monil Ajitbhai 11 December 2015 (has links)
This experiment was conducted to determine the differences in meat quality (cooking loss and shear force), descriptive sensory characteristics, consumer acceptance, and whole muscle proteomes between normal and Pale, Soft, and Exudative (PSE) broiler breast meat. Male Hubbard × Cobb 500 birds (n = 1,050) were raised in commercial houses. Prior to harvest, a sample of the broilers (n = 900) were subjected to short-term stress (38 °C for 2 h), and the remaining broilers (n = 150) were maintained at control conditions (21 °C for 2 h). From the stressed and control condition broilers, breast samples were characterized by pH24 and L*24 as normal (pH24 5.8-6.2, L*24 45-55) or PSE (pH24 5.4-5.7, L*24 55-65). Normal chicken breast meat had lower shear force values than PSE meat (P < 0.05). Based on sensory descriptive analysis, normal cooked chicken breast was more tender and juicier than PSE breast meat (P < 0.05). Consumer sensory analysis results indicated that 81% of consumer panelists liked normal breast meat whereas 62% of the panelists liked PSE breast meat. Whole muscle proteome profiling identified fifteen differentially abundant proteins (P < 0.05) in normal and PSE meat samples. Actin alpha, myosin heavy chain, phosphoglycerate kinase, creatine kinase M type, beta-enolase, carbonic anhydrase 2, proteasome subunit alpha, pyruvate kinase, and malate dehydrogenase were over-abundant in PSE meat whereas phosphoglycerate mutase-1, alpha-enolase, ATP-dependent 6-phosphofructokinase, and fructose 1, 6-bisphosphatase were over-abundant in normal meat. In addition, normal and PSE broiler breast meat were sampled from commercial plants and evaluated for meat quality attributes (pH, color, cooking loss, and tenderness) and their whole muscle proteome. Normal chicken breast meat had lower shear force values than PSE meat (P < 0.05). Proteome analysis revealed five differentially abundant proteins (P < 0.05) between the normal and PSE chicken breast samples. Glycolytic enzymes (beta-enolase and fructose-bisphosphate aldolase C) were over-abundant in PSE breast meat. Myofibrillar protein (myosin heavy chain) was over-abundant in PSE breast meat. In conclusion, results indicated that differences in proteome abundance could be related to the meat quality differences between normal and PSE breast meat.

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