An investigation into the analysis of ecdysones and other steroid hormones

As an aid to the analysis of ecdysones (arthropod moulting hormones), an investigation has been carried out to find an efficient and sensitive method for determining them by chromatography. A series of fluorocarbonsilanes were synthesized and tested as electron capturing derivatives for gas chromatography. Flophemesyl* (*pentafluorophenyldimethylsilyl) derivatives of mammalian steroids were volatile and sensitive to detection. The derivatives produced characteristic mass spectra with a greater proportion of the ion current carried by hydrocarbon fragments than with other siloxy derivatives making flophemesyl derivatives more suitable for structural determinations. A series of flophemesyl reagents were developed for selectively protecting hydroxyl groups in different steric environments. New methods of synthesis of some of these reagents and analytical techniques for their identification were established. In their mass spectra, unusual rearrangements were found to occur between the fluorine atoms of the pentafluorophenyl ring and the methyl groups bonded to silicon, giving hydrofluorocarbon tropylium-type ions. Flophemesyl derivatives, although useful for mammalian steroids did not give volatile derivatives of ecdysones. The introduction of the pentafluorophenyl ring into steroids as pentafluorophenylhydrazones or pentafluorophenylboronic esters was attempted. The hydrazones, as ketone derivatives, had poor GC characteristics and limited stability when exposed to light or the atmosphere. The pentafluorophenylboronic esters were susceptible to disproportionationin the presence of traces of water or other strong nucleophiles. Boron can be selectively detected with a nitrogen thermionic detector. Boronic esters of model steroids were detected at lower levels than with the FID, but the estimated sensitivity for ecdysones was insufficient for trace level analysis. As ecdysone TMS ethers fragment to produce mass spectra containing a few ions of relatively high intensity, the possibility of using the mass spectrometer as a gas chromatographic detector was investigated. The ecdysone derivatives could only be chromatographed at high temperatures as low carrier gas flow rates had to be used to meet the vacuum requirements of the mass spectrometer. An excessive column background made quantification difficult at trace levels. Optimum GC-MS conditions for steroid analysis were established. The model steroids 28,30-dihydroxy-5a-cholestane and 28,3$,lUa-tri- hydroxy-50-cholest-7-en-6-one were prepared by published procedures; 5a-cholest-7-en-6-one and 14a-hydroxy-5o-cholest-7~en-6-one were synthesised for the first time in good overall yield. In an investigation of the formation of ecdysone THS ethers and the formation of heptafluorobutyrate esters by an exchange reaction with the TMS ethers, it was discovered that the ecdysone nucleus contains the features necessary for electron capture without the need for the formation of halogenated derivatives. The electrophore was identified as the unsaturated ketone, the C-14 oxy substituent with a smaller contribution from the more remote 28,30-oxy substituents. The rate of formation of the TMS ethers of ecdysterone hydroxyl groups with trimethylsilylimidazole was found to be 2,3,22,25>20>>1*U The degree of TMS ether formation in ecdysone and ecdysterone was confirmed by mass spectrometry of the derivatives and also by selective silylation of model steroids. Ecdysones in biological samples were determined as their TMS ethers after a preliminary extraction, solvent partition and TLC separation from impurities. The method has been applied to determine the daily changes in ecdysone content in the desert locust, Schistocerca gregaria. A brief survey of high pressure liquid chromatography illustrated the potential of this technique for the detection and separation of ecdysones

Comparison of Aerobic Training Methods on V02 Max, Body Composition and Anaerobic Power.

Recent research has utilized intensity as a primary means to define training methods for improving aerobic capacity (VO2 max). Alternative ways of classifying training techniques must be examined to elucidate optimal practices for aerobic capacity enhancement. PURPOSE: To investigate the potential impact of various aerobic training methods on V02, body composition and anaerobic power. METHODS: Thirty-four healthy male & female subjects (18-30yrs) participated in an equated volume supervised running workout for six weeks utilizing two alternate training methods. Group one (N = 17, 21 ± 3 yr) participated in Interval Training Distance (ITD) and group two (N = 17, 21 ± 3 yr) participated in Long Slow Distance (LSD). All subjects participated in a familiarity session (FAM), a Pre-Test (T1) and a Post-Test (T2) . Each testing session consisted of a V02 Max, a 30 second Wingate and body composition assessment. Data were analyzed by a two-way ANOVA with repeated measures. Significance was set at p \u3c 0.05 and adopted throughout. RESULTS: The ITD and LSD groups experienced significant increases (p \u3c 0 .001) in VO2 max, with 9.05% (4.19 ± 4.15 ml/kg/min) and 3.18% (1.39 ± 3.67 ml/kg/min) increases respectively. A significant interaction (p \u3c 0.05) in VO2 max occurred between groups, as the ITD group displayed a 302% greater increase when compared to the LSD group. Body fat percentage significantly decreased (p \u3c 0.01) in the ITD (1.08 ± 1.90%) and LSD (1.55 ± 3.21%) groups, while a significant reduction (p \u3c 0.05) in total body weight was also observed. CONCLUSION: The findings of this study suggest that the ITD training method has a greater impact on aerobic capacity than LSD training method. However, both ITD and LSD training methods had a significant impact on aerobic capacity, body weight, and body composition

Gauge coupling beta functions to four-loop order in the Standard Model

We compute the beta functions of the three Standard Model gauge couplings to four-loop order in the modified minimal subtraction scheme. At this order a proper definition of $\gamma_5$ in $D=4-2\epsilon$ space-time dimensions is required; however, in our calculation we determine the $\gamma_5$-dependent terms by exploiting relations with beta function coefficients at lower loop orders.Comment: 6 pages, 2 figure

Gradient flows in three dimensions

The α-function is a proposed quantity defined for quantum field theories which has a monotonic behaviour along renormalisation group flows, being related to the β-functions via a gradient flow equation involving a positive definite metric. We demonstrate the existence of a candidate α-function for renormalisable Chern-Simons theories in three dimensions, involving scalar and fermion fields, in both non-supersymmetric and supersymmetric cases

The Impact of Differing Types of Physical Activity on Weight Loss, Strength, VO2 max, and the Various Metabolic Hormones.

PURPOSE: The purpose of this investigate the impact of differing types of physical activity on weight loss, strength, VO2 max, and various metabolic hormones. METHODS: Eleven sedentary and overweight male/females participated in this study and were randomly assigned to one of two exercise groups: aerobic training (A) (N = 4, 40 ± 8.7 yrs 165 ± 8.3cm, 89 ± 16 kg), or aerobic training plus resistance training (ART) (N = 7, 43 ± 10 yrs, 171 ± 8.7 cm, 91 ± 12 kg). Training protocols for the two exercise groups consisted of 30 min of aerobic exercise five days per week at 60-70% of heart rate max and 30 minutes of aerobic exercise three days per week at 60-70% of heart rate max plus two days of moderate intensity resistance exercise per week for the (A) and (ART) groups, respectively. Baseline testing consisted of weight, hip, and waist measurements, and body composition analysis using bioelectrical impedance. Participants donated approximately 20 ml of fasting blood for the analysis of clinical chemistry profiles, WBC counts, and the hormones insulin, leptin, and cortisol. Following these assessments, VO2 max, upper-body strength, and lower-body strength was established using standard procedures. All baseline assessments were repeated at 4 and 8 weeks of the study. Statistical analyses utilized a two-way ANOVA with repeated measures for all criterion variables (p\u3c0.05). RESULTS: A significant (p \u3c 0.05) increase in upper and lower body strength was observed in both A and ART groups, however there was no significant difference between groups. A significant group x time interaction (p \u3c 0.05) was observed for body weight (ART: -1.5 ± 0.3 lbs; A: 3 ± 0.5 lbs). No significant (p \u3e 0.05) main effects for group or time were observed for the criterion variables body fat, VO2 max, and the hormones insulin, leptin, and cortisol. Furthermore, neither protocol had a significant impact on body fat or VO2 max. CONCLUSIONS: It can be concluded that aerobic exercise coupled with resistance training for 8 weeks yielded greater results in weight loss than aerobic training alone. No marked changes were noted on the affects of any type of exercise regiment on body composition, VO2 max, or the hormones leptin, insulin, and cortisol over the 8-week study

The Effects of an Energy Increasing Supplement on Markers of V02 max, Body Composition, and Anaerobic Power

Research suggests that energy increasing supplement ingestion prior to prolonged aerobic exercise (\u3e60minutes) can improve aerobic capacity (VO2 Max). Energy increasing supplements affect on reduced aerobic training periods (\u3c60\u3eminutes) lack definitive empirical evidence. PURPOSE: To investigate the potential impact of an energy increasing supplement on aerobic training, body composition and anaerobic power. METHODS: Thirty-three healthy male and female subjects (18-30yrs) participated in an equated volume supervised running workout for six weeks utilizing long slow distance. Group one (N = 17, 21 ± 3 yr) participated in long slow distance training as a Placebo group void of any dietary instructions or interventions. Group two (N = 16, 21 ± 3 yr) participated in long slow distance training and was provided with a GU Energy Gel packet and 8 oz. of water fifteen minutes prior to the workout. All subjects participated in a familiarity session (FAM), a Pre-Test (T1) and a Post-Test (T2). Each testing session consisted of a V02 Max, a 30 second Wingate and body composition assessment. Data were analyzed by a two-way ANOVA with repeated measures. Significance was set at p \u3c 0.05 and adopted throughout. RESULTS: The GU and Placebo groups experienced significant increases (p \u3c 0.001), in VO2 max, with 9.71% (4.06 ± 2.68 ml/kg/min) and 2.81% (1.26 ± 2.25 ml/kg/min) increases respectively. A significant interaction (p \u3c 0.005) in VO2 max occurred between groups, as the GU group displayed a 322% greater increase when compared to the Placebo group. Body fat percentage significantly decreased (p \u3c 0.05) in the GU (0.76 ± 2.47%) and Placebo (1.55 ± 3.21%) groups without a significant reduction in total body weight at a p \u3c 0.05 significant level. No change was observed in Wingate peak or mean power (p \u3c 0.05). CONCLUSION: The findings of this study suggest GU Energy Gel supplementation has a more profound impact on aerobic capacity when compared to a Placebo under identical training protocols. However, both GU Energy Gel and Placebo supplementation had a significant effect on aerobic capacity and body fat percentage

The effects of a commercially available botanical supplement on strength, body composition, power output, and hormonal profiles in resistance-trained males

<p>Abstract</p> <p>Background</p> <p>Fenugreek (<it>Trigonella foenum-graecum</it>) is a leguminous, annual plant originating in India and North Africa. In recent years Fenugreek has been touted as an ergogenic aid. The purpose of this study was to evaluate the effects of Fenugreek supplementation on strength and body composition.</p> <p>Methods</p> <p>49 Resistance trained men were matched according to body weight and randomly assigned to ingest in a double blind manner capsules containing 500 mg of a placebo (N = 23, 20 ± 1.9 years, 178 ± 6.3 cm, 85 ± 12.7 kg, 17 ± 5.6 %BF) or Fenugreek (N = 26, 21 ± 2.8 years, 178 ± 6 cm, 90 ± 18.2 kg, 19.3 ± 8.4 %BF). Subjects participated in a supervised 4-day per week periodized resistance-training program split into two upper and two lower extremity workouts per week for a total of 8-weeks. At 0, 4, and 8-weeks, subjects underwent hydrodensiometery body composition, 1-RM strength, muscle endurance, and anaerobic capacity testing. Data were analyzed using repeated measures ANOVA and are presented as mean ± SD changes from baseline after 60-days.</p> <p>Results</p> <p>No significant differences (p > 0.05) between groups were noted for training volume. Significant group × time interaction effects were observed among groups in changes in body fat (FEN: -2.3 ± 1.4%BF; PL: -0.39 ± 1.6 %BF, p < 0.001), leg press 1-RM (FEN: 84.6 ± 36.2 kg; PL: 48 ± 29.5 kg, p < 0.001), and bench press 1-RM (FEN: 9.1 ± 6.9 kg; PL: 4.3 ± 5.6 kg, p = 0.01). No significant interactions was observed among groups for Wingate power analysis (p = 0.95) or muscular endurance on bench press (p = 0.87) or leg press (p = 0.61). In addition, there were no changes among groups in any clinical safety data including lipid panel, liver function, kidney function, and/or CBC panel (p > 0.05).</p> <p>Conclusion</p> <p>It is concluded that 500 mg of this proprietary Fenugreek extraction had a significant impact on both upper- and lower-body strength and body composition in comparison to placebo in a double blind controlled trial. These changes were obtained with no clinical side effects.</p

<i>In situ</i> monitor of superhydrophobic surface degradation to predict its drag reduction in turbulent flow

In situ monitoring is the most insightful technique to examine superhydrophobic surface degradation as it provides real-time information on the liquid–solid interface in a continuous, noninvasive manner. Using reflecting-pixel intensity, we introduced a simple method to characterize in situ the air-plastron over a superhydrophobic surface in a turbulent channel flow. Prior to the turbulent experiments, a no-flow hydrostatic test was carried out to determine a critical absolute pressure under which the surfaces are able to maintain the air layer for a prolonged period of time. Pressure-drop and velocity measurements were conducted in a series of turbulent flow tests. Resulting from the coupling effects of normal and shear stresses over the plastron, the air layer was progressively lost with flow time which caused the drag ratio (i.e., the friction factor ratio between superhydrophobic and smooth surfaces) to increase. Meanwhile, the average pixel intensity also increased with time and exhibited a consistent trend with the drag ratio evolution. At a fixed near-wall y/h location (within the viscous sublayer), the velocity increased with time since the shear stress increased. However, a velocity measurement at the center of the channel exhibited a decrease, consummate with an overall downward shift of the velocity profile. Both pressure-drop and velocity results were observed to be correlated with the average pixel intensities of the images captured over the surfaces, and therefore, this is a suitable proxy measure of the plastron. This technique is confirmed to be valid for monitoring the air layer and, hence, predicting the consequent loss of drag reduction.</jats:p