The Effect of Green Tea Extract on Endurance Performance in Young Adults

Background: Green tea is rich in catechin, a polyphenolic antioxidant. Consumption of green tea or extract from green tea has been shown to result in weight loss, increased fat oxidation, and elevated energy expenditure in mice and humans. Green tea consumption has also been shown to result in increased exercise endurance in mice and improved maximal oxygen uptake (VO2max) in humans. It is not clearly known whether green tea consumption would increase exercise endurance in humans. Objective: The aim of this study was to determine if the daily consumption of decaffeinated green tea extract for 4-5 weeks, would improve exercise endurance in humans, as measured by running 2.5 miles on an indoor track. Subjects, Design, and Methods: This study was based on a randomized, double-blind design. Fourteen, normal, healthy individuals volunteered for participation and completed the study. They were divided into two groups (n= 7 for each group). All participants completed 2 endurance trials, 1 at the baseline and 1 at the conclusion of the study. Each trial consisted of a 2.5 mile run around the GSU Recreation Center indoor track. One group consumed green tea extract pill containing 900 mg catechins and the other group consumed a placebo for 4-5 weeks between run trials. Results: Green tea and placebo groups improved their running times, however, there was no significant difference between these two groups in mean end time (P = 0.74). Under one statistical analysis, the green tea group significantly improved their running time compared to baseline (P = 0.019), while the placebo group did not. However, under another statistical analysis (removing one participant due to possible skewing effect), both groups significantly improved their running time over baseline (P\u3c 0.05). Conclusions: This study was not able conclusively ascertain whether or not the daily consumption of green tea improved endurance performance as measured by 2.5 mile run times. Results of this study should be used with caution due to small sample size. Future studies are warranted on the impact of green tea consumption on exercise endurance, using a longer duration and a larger sample size than has been studied

Fluorescence in situ hybridization of YAC clones after Alu-PCR amplification

Alu-PCR protocols were optimized for the generation of human DNA probes from yeast strains containing yeast artificial chromosomes (YACs) with human inserts between 100 and 800 kb in size. The resulting DNA probes were used in chromosome in situ suppression (CISS) hybridization experiments. Strong fluorescent signals on both chromatids indicated the localization of specific YAC clones, while two clearly distinguishable signals were observed in ≥90% of diploid nuclei Signal intensities were generally comparable to those observed using chromosome-specific alphoid DNA probes. This approach will facilitate the rapid mapping of YAC clones and their use in chromosome analysis at all stages of the cell cycle

Momentum Analyticity and Finiteness of the 1-Loop Superstring Amplitude

The Type II Superstring amplitude to 1-loop order is given by an integral of $\vartheta$-functions over the moduli space of tori, which diverges for real momenta. We construct the analytic continuation which renders this amplitude well defined and finite, and we find the expected poles and cuts in the complex momentum plane.Comment: 10pp, /UCLA/93/TEP/

Dispersion Relations in String Theory

We analyze the analytic continuation of the formally divergent one-loop amplitude for scattering of the graviton multiplet in the Type II Superstring. In particular we obtain explicit double and single dispersion relations, formulas for all the successive branch cuts extending out to plus infinity, as well as for the decay rate of a massive string state of arbitrary mass 2N into two string states of lower mass. We compare our results with the box diagram in a superposition of $\phi^3$-like field theories. The stringy effects are traced to a convergence problem in this superposition.Comment: 17 pages, COLUMBIA-YITP-UCLA/93/TEP/45 (figures fixed up

Inverse molecular design from first principles: Tailoring organic chromophore spectra for optoelectronic applications

The discovery of molecules with tailored optoelectronic properties, such as specific frequency and intensity of absorption or emission, is a major challenge in creating next-generation organic light-emitting diodes (OLEDs) and photovoltaics. This raises the following question: How can we predict a potential chemical structure from these properties? Approaches that attempt to tackle this inverse design problem include virtual screening, active machine learning, and genetic algorithms. However, these approaches rely on a molecular database or many electronic structure calculations, and significant computational savings could be achieved if there was prior knowledge of (i) whether the optoelectronic properties of a parent molecule could easily be improved and (ii) what morphing operations on a parent molecule could improve these properties. In this Perspective, we address both of these challenges from first principles. We first adapt the Thomas-Reiche-Kuhn sum rule to organic chromophores and show how this indicates how easily the absorption and emission of a molecule can be improved. We then show how by combining electronic structure theory and intensity borrowing perturbation theory we can predict whether or not the proposed morphing operations will achieve the desired spectral alteration, and thereby derive widely applicable design rules. We go on to provide proof-of-concept illustrations of this approach to optimizing the visible absorption of acenes and the emission of radical OLEDs. We believe that this approach can be integrated into genetic algorithms by biasing morphing operations in favor of those that are likely to be successful, leading to faster molecular discovery and greener chemistry