Indirect fluorometric detection techniques on thin layer chromatography and effect of ultrasound on gel electrophoresis

Thin-layer chromatography (TLC) is a broadly applicable separation technique. It offers many advantages over high performance liquid chromatography (HPLC), such as easily adapted for two-dimensional separation, for whole-column detection and for handling multiple samples, etc. However, due to its draggy development of detection techniques comparing with HPLC, TLC has not received the attention it deserves. Therefore, exploring new detection techniques is very important to the development of TLC. It is the principal purpose of this dissertation to present a new detection method for TLC--indirect fluorometric detection method. This detection technique is universal, sensitive, nondestructive, and simple. This will be described in detail from Sections I through Section V;Section I and III describe the indirect fluorometric detection of anions and nonelectrolytes in TLC. They are based on the displacement of fluorophore by the sample molecule, which cause a decrease of fluorescence. The negative signals can be monitored, i.e., analytes can be detected indirectly;In Section II, a detection method for cations based on fluorescence quenching of ethidium bromide is presented. Cations such as Cu[superscript]2+, Cr[superscript]3+ and Hg[superscript]+ can be separated on silica gel TLC plate and detected by quenching the red fluorescence of ethidium bromide;In Section IV, a simple and interesting TLC experiment is designed, three different fluorescence detection principles are used for the determination of caffeine, saccharin and sodium benzoate in beverages;A laser-based indirect fluorometric detection technique in TLC is developed in Section V. The new technique can be easily used for quantitative measurements because of its two-dimension scanning capability. With this technique a detection limit of 6 pg can be achieved;Section VI is totally different from Sections I through V. An ultrasonic effect on the separation of DNA fragments in agarose gel electrophoresis is investigated. It is found that the ultrasound improves the separation of DNA fragments without degrading them, a phenomenon that is totally different from that of ultrasonic scission

Method and Apparatus for Cancer Screening

A method and apparatus for detection of pteridine levels in a biological sample using CE-LIF which is useful for early cancer screening involving fully oxidizing pteridine compounds in a sample such as a urine sample, subjecting to CE-LIF to assess compound concentration, and compare to expected levels in for healthy or cancer-bearing patients

BBR-induced Stark shifts and level broadening in helium atom

The precise calculations of blackbody radiation (BBR)-induced Stark shifts and depopulation rates for low-lying states of helium atom with the use of variational approach are presented. An effect of the BBR-induced induced Stark-mixing of energy levels is considered. It is shown that this effect leads to a significant reduction of lifetimes of helium excited states. As a consequence the influence of Stark-mixing effect on the decay rates of metastable states in helium is discussed in context of formation processes of the cosmic microwave background

Early cancer screening with P-scan technology

Advances in Biomaterials and Medical Devices PanelEarly detection and treatment of cancers continue to be the best line of defense to prevent fatalities as a result of developing cancer. Several tests have been developed, such as mammograms for breast cancer and colonoscopies for colon cancer, but most of these tests are invasive, uncomfortable and are not always able to detect cancer earlier enough to provide a winning scenario for patients. Some cancers are still very difficult to diagnose in the early stage, such as ovarian cancer, colorectal cancer, and some liver cancers. In our study, we have developed a P-scan instrument to successfully identify and quantify six pteridines in urine samples. The data demonstrated a great correlation between pteridine levels and cancer development. The detailed experimental conditions will be presented at the life science summit. After analysis of over 60 urine samples from cancer patients, we also discovered that two chemical components exist only in the urine of cancer patients but are not present in individuals who do not have cancers

Fiber-Optic Micro-Probes for Measuring Acidity Level, Temperature, and Antigens

A pH micro-probe, a temperature micro-probe, and an immuno-based micro-probe each include a shaft for transmuting an input light signal and a tip for inserting into a cell or other substance for measuring pH, temperature, and/or antigens. The pH micro-probe and the temperature micro-probe each include a luminescent material positioned on the tip of the micro-probe. The light signal excites the luminescent material so that the luminescent material emits a luminescent light signal. The luminescent light signal has a property value dependent on the pH or temperature being measured and reflects back through the shaft for being measured by a light signal measuring device. The immuno-based micro-probe includes a reflective material that has an effective refractive index dependent on the number of antigen-antibody bonds present on the reflective material

Means and method of detection in chemical separation procedures

A means and method for indirect detection of constituent components of a mixture separated in a chemical separation process. Fluorescing ions are distributed across the area in which separation of the mixture will occur to provide a generally uniform background fluorescence intensity. For example, the mixture is comprised of one or more charged analytes which displace fluorescing ions where its constituent components separate to. Fluorescing ions of the same charge as the charged analyte components cause a displacement. The displacement results in the location of the separated components having a reduced fluorescence intensity to the remainder of the background. Detection of the lower fluorescence intensity areas can be visually, by photographic means and methods, or by automated laser scanning

Large Enhancement of Spontaneous Emission Rates of InAs Quantum Dots in GaAs Microdisks

Control of spontaneous emission in a microcavity has many important applications, e.g. improvement of the efficiency of light emitting devices. InAs quantum dots (QDs) embedded in microdisks are ideal systems for spontaneous emission control. The whispering gallery (WG) modes of microdisks have low volume and high quality factor. The homogeneous linewidth of InAs quantum dots is smaller than the spectral width of WG modes. Thus, a large enhancement of the spontaneous emission rates should be expected for QDs coupled to WG modes. However, large inhomogeneous broadening of the QD energy levels and random spatial distribution of the QDs in a microdisk lead to a broad distribution of the spontaneous emission rates. Using an efficient regularized method based on the truncated singular value decomposition and the non-negative constraints, we extract the distribution of spontaneous emission rates from the temporal decay of emission intensity. The maximum spontaneous emission enhancement factor exceeds 10

Undergraduate Chemical Research -- A Unique Learning Experience for Students

The importance of undergraduate research was first addressed in the in early 1930s.Since that time, many universities and colleges have developed undergraduate research programs. Based on updated reports, 4-7 undergraduate research has grown exponentially over the last decade. I strongly believe that undergraduate research is a unique learning experience for our undergraduate students. It can often play the pivotal role for an undergraduate student to choose chemistry as their future profession. Several researchers with extensive undergraduate research experience have already clearly described the crucial effect of undergraduate research to students in their development of problem solving, critical thinking and chemistry knowledge. 4, 8-19 Undergraduate research is truly an active learning process for the students since they apply the knowledge they learn in the classroom to a real research project. in addition, the students expand their knowledge during the research process because some of the knowledge they need in research is not learned from their normal classes. This is especially true for my students. My primary research is the development of new instrumentation and procedures for bio-analysis of DNAs, proteins, peptides, amino acids, small molecules, cancer markers, and other biological compounds. These methods commonly employ high performance liquid chromatography (HPLC), high performance thin layer chromatography (HPTLC), and high performance capillary electrophoresis (HPCE). I have focused on pre-cancer screening for the past two years and will continue this research project for the years to come. Pre-cancer screening at the single-molecule level is my eventual goal. Students entering my research group are typically sophomores with essentially no knowledge and experience in capillary electrophoresis. Some of them have never heard of capillary electrophoresis. They have to learn from zero. They have to read relevant material that I provide for them and they have to perform a literature search to determine the status of their research projects. What a challenge! It is very important that they know how to perform literature searches at the library or online. in this way, they will determine what has and has not been done in their area of interest. Based on my experience directing undergraduate research at Truman State University for the past ten years, the students involved in research are easily developed into logical thinkers. Students in research always need to ask themselves several questions: Why is this happening? Is this the result I want? Is this better or worse than before? What can I do to make it better? Since they have to solve all the problems encountered during the research project, they will gradually become problem solvers. I call this, #going##through##the##frustration##period.# to promote undergraduate chemical research, financial support and dissemination opportunities are critically important. Funding is needed for student salaries, supplies, and modem equipment so they can perform meaningful research. in order to encourage undergraduate research, many universities have established internal grants to fund undergraduate research projects. in addition, national funding agencies have also set aside funds especially for undergraduate institutions, such as the Research for Undergraduate Institutions (RUI) and the Research Experience for Undergraduates (REU) from the National Science Foundation, and Research Corporation. of course, faculty can apply for other grants too, such as the AREA grant from NIH, the PRF grant administered by ACS, and so on. Truman State University has offered internal research grants for over ten years, which greatly stimulates the growth of undergraduate research at Truman. as I stated above, the other factor to encourage undergraduate research is opportunities for our students to present their research results. in many cases, the results from our students are not significant enough to be presented at national or international conferences. However, students get very excited when they have an opportunity to present their findings or results in special mediums for undergraduates. in addition, students also learn from each other during the conference as they discuss their results and ideas with their peers. Currently, several good local and national mediums are available for our undergraduate students to present their research, such as the Missouri Academy of Science (MAS), the National Conference on Undergraduate Research (NCUR), the Council on Undergraduate Research (CUR), the Argonne Undergraduate Research Symposium, the Pittsburgh Conference, and so on. in addition, Truman State University has its own undergraduate research symposium each spring. We all should utilize these media and encourage our students to share their research results with others

Indirect Fluorometric Detection Techniques on Thin Layer Chromatography and Effect of Ultrasound on Gel Electrophoresis

Thin-layer chromatography (TLC) is a broadly applicable separation technique. It offers many advantages over high performance liquid chromatography (HPLC), such as easily adapted for two-dimensional separation, for whole-column detection and for handling multiple samples, etc. However, due to its draggy development of detection techniques comparing with HPLC, TLC has not received the attention it deserves. Therefore, exploring new detection techniques is very important to the development of TLC. It is the principal purpose of this dissertation to present a new detection method for TLC--indirect fluorometric detection method. This detection technique is universal, sensitive, nondestructive, and simple. This will be described in detail from Sections I through Section V;Section I and III describe the indirect fluorometric detection of anions and nonelectrolytes in TLC. They are based on the displacement of fluorophore by the sample molecule, which cause a decrease of fluorescence. The negative signals can be monitored, i.e., analytes can be detected indirectly;In Section II, a detection method for cations based on fluorescence quenching of ethidium bromide is presented. Cations such as Cu2+, Cr3+ and Hg+ can be separated on silica gel TLC plate and detected by quenching the red fluorescence of ethidium bromide;In Section IV, a simple and interesting TLC experiment is designed, three different fluorescence detection principles are used for the determination of caffeine, saccharin and sodium benzoate in beverages;A laser-based indirect fluorometric detection technique in TLC is developed in Section V. The new technique can be easily used for quantitative measurements because of its two-dimension scanning capability. With this technique a detection limit of 6 pg can be achieved;Section VI is totally different from Sections I through V. An ultrasonic effect on the separation of DNA fragments in agarose gel electrophoresis is investigated. It is found that the ultrasound improves the separation of DNA fragments without degrading them, a phenomenon that is totally different from that of ultrasonic scission