GONADOTROPHIN RESPONSES TO GnRH PULSES IN HYPOGONADOTROPHIC HYPOGONADISM: LH RESPONSIVENESS IS MAINTAINED IN THE PRESENCE OF LUTEAL PHASE CONCENTRATIONS OF OESTROGEN AND PROGESTERONE

LH pulse secretion changes during the menstrual cycle from a rapid regular pattern in the follicular phase to a slower and irregular pattern in the luteal phase. To determine whether the irregular LH pulse pattern in the luteal phase reflects altered GnRH secretion or altered pituitary responsiveness to GnRH, we gave low dose GnRH pulses (25 ng/kg i.v.) every 2 h or every hour for 10 or 12 d to three women with isolated GnRH deficiency. After 4 d of GnRH alone, oestradiol (E 2 ) was given and after 6 d progesterone (P) was added to mimic the hormonal milieu of the luteal phase. LH and FSH were measured every 4 h throughout and also every 20 min for 6 or 12 h, before and after GnRH alone (day 0 and day 4), after E 2 (day 6), and after E 2 + P (day 10 and day 12). Both GnRH pulse frequencies resulted in a rapid increase in plasma FSH to peaks on day 4 (every 2 h) and day 2 and 3 (every hour). FSH concentrations then declined as plasma E 2 rose to 50–80 pg/ml reflecting the selective inhibitory effect of E 2 on FSH release. Plasma LH was also increased after the hourly GnRH injections and this regimen was associated with a more rapid rise in E 2 reflecting follicular maturation. In contrast to the differences in mean hormone concentrations, administration of GnRH at both frequencies resulted in sustained one-on-one responsiveness of LH that was maintained in the presence of both oestrogen and progesterone at mid-luteal phase concentrations. We conclude that the slow frequency of LH pulses observed during the luteal phase reflects decreased GnRH pulse frequency rather than impaired pituitary responsiveness to GnRH.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74947/1/j.1365-2265.1987.tb00786.x.pd

Effects of follicular phase exercise on luteinizing hormone pulse characteristics in sedentary eumenorrhoeic women

OBJECTIVE Current studies reveal little regarding the Inception of exercise-induced LH changes during physical training. This study aimed to assess the susceptibility of the hypothalamic–pituitary axis to the acute physical stress of exercise in untrained, physically inactive women. The acute effects of submaximal endurance exercise upon the pulsatile LH secretion in the follicular phase were compared with those accompanying leisurely strolling for a similar time period. SUBJECTS All subjects were eumenorrhoelc, as determined by biphasic temperature patterns, detection of the urinary LH surge, and mid-luteal serum progesterone levels. Subjects were not physically active and had little history of strenuous exercise ( V o 2 max = 38·0 ± 1·8) (mean ± SEM) ml/kg/min). DESIGN All women completed a 13·5-hour pulsatility test which included three consecutive 20-minute runs on a treadmill at 50, 60 and 70% of the subjects’maximum oxygen uptake ( n = 16). Six of these same subjects completed a separate test on another occasion in which one hour of leisurely strolling was substituted for exercise. Blood was sampled every 10 minutes via an indwelling cannula for 4·5 hours before and 8 hours after one hour of exercise and or strolling. MEASUREMENTS A pulse algorithm (Pulsar) was used to quantify LH pulse characteristics. RESULTS Exercise produced no significant effects upon LH pulse frequency or mean serum LH concentration. However, exercise of moderate intensity caused a significant increase in LH pulse amplitude ( P < 0·05). Strolling produced no significant changes in LH secretion. CONCLUSION Acute exercise of moderate intensity in the follicular phase of untrained women is an insufficient stimulus to inhibit the GnRH pulse generator in the post-exercise period, yet may produce a slight stimulatory effect on the amount of LH released per pulsePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73507/1/j.1365-2265.1994.tb02794.x.pd

Vine grammar generative system

Graphic designers always take both time and efforts when they are creating a decorative pattern with complicated curves and a great deal of motifs. Although there are many sourcebooks of decorative patterns, the satisfaction of the results couldnit accomplish with designeris requirements. Thus, graphic designers need a faster and easier system to create decorative patterns in classical style. There are a few effiencient methods to analysis curves and surfaces in the development of shape grammars. The purpose of this research is to develop Vine Grammar based on shape grammars. The vine grammar analyses principles hidden in the language of deisgn works to create the order, then generates design by using Bézier curves. This research also presents the development of a decorative pattern generative system called Shlishi by using FLASH Action Script 2.0. The grammar can be applied with computers and to verify rules quickly by Shlishi. The intention of this research is to make graphic designers to use these rules to create decorative patterns of plants in classic style and to produce satisfactory results for designer more efficiently or to make the results the source materials for the follow-up design works

Heat transfer optimization of SCO2 porous flow based on Brinkman model

The purpose of this study is to obtain the optimal operating condition in order to find the maximum supercritical CO2 heat extraction in the enhanced geothermal system (EGS). In this study, the heat transfer model conjugated with the Brinkman model is used to evaluate the thermal behavior in the reservoir of the EGS. This numerical model is validated by experiment. Optimization is processed based on the Nelder-Mead approach. The optimal operating conditions are proposed with different pressure, porosity. This study will build the optimal platform of heat source of geothermal power plant

Conducting and magnetic behaviors of monodispersed iron oxide/polypyrrole nanocomposites synthesized by in situ chemical oxidative polymerization

This study describes the preparation of nanocomposites fabricated from monodispersed iron oxide (Fe(3)O(4)) and polypyrrole (PPy) by in situ chemical oxidative polymerization. The monodispersed 4 nm Fe(3)O(4) nanoparticles which served as cores were synthesized using the thermal decomposition of a mixture of Iron (III) acetylacetonate and oleic acid in the presence of high boiling point solvents. The resulting nanoparticles were further dispersed in an aqueous solution with anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate to form micelle/Fe(3)O(4) spherical templates that avoid the aggregation of Fe(3)O(4) nanoparticles during the further preparation of the nanocomposites. The Fe(3)O(4)/PPy nanocomposites were then synthesized via in situ chemical oxidative polymerization on the surface of the spherical templates. Both field-emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM) images indicate that the resulting Fe(3)O(4) nanoparticles are close to spherical dots with a particle size of about 4 nm and a standard deviation of less than 5% (4 +/- 0.2 nm). Structural and morphological analysis using FESEM and HRTEM showed that the fabricated Fe(3)O(4)/PPy nanocomposites are core (Fe(3)O(4))-shell (PPy) structures. Morphology of the nanocomposites shows a remarkable change from spherical to tube-like structures as the content of monodispersed Fe(3)O(4) nanoparticles increases from 9% up to 24 wt %. The conductivities of these Fe(3)O(4)/PPy nanocomposites are about six times higher than those of PPy without Fe(3)O(4). (c) 2007 Wiley Periodicals, Inc

Investigating the heat transfer phenomena of CO2-EGS in the reservoir by experiment verification

The purpose of this study is to find the heat transfer phenomena of CO2-EGS in the reservoir. The heat transfer model conjugated with the Brinkman model is used. This numerical model is validated by the experiment of supercritical CO2. The heat transfer coefficient of experiment is derived from the thermal resistance method of comparison between numerical model and experiment. Further, the heat transfer coefficients with different operating conditions are build in this study. This study will provide the better combination of operating conditions for the improved heat extraction

Investigating the heat transfer phenomena of CO

The purpose of this study is to find the heat transfer phenomena of CO2-EGS in the reservoir. The heat transfer model conjugated with the Brinkman model is used. This numerical model is validated by the experiment of supercritical CO2. The heat transfer coefficient of experiment is derived from the thermal resistance method of comparison between numerical model and experiment. Further, the heat transfer coefficients with different operating conditions are build in this study. This study will provide the better combination of operating conditions for the improved heat extraction

Probiotic Lactobacillus casei Expressing Human Lactoferrin Elevates Antibacterial Activity in the Gastrointestinal Tract

In this study, Lactobacillus casei was used to deliver and express human lactoferrin (hLF) to protect the host against bacterial infection. Full-length hLF cDNA was cloned into a Lactobacillus-specific plasmid to produce the L. casei transformants (rhLF/L. casei). Antimicrobial activity of recombinant hLF was examined in inhibition of bacteria growth in vitro. A mouse model was established to test in vivo antibacterial activity and protective effect of orally-administered probiotic L. casei transformant in the gastrointestinal tract. Trials were conducted in which animals were challenged with E. coli ATCC25922. E. coli colony numbers in duodenal fluid from the group fed with rhLF/L. casei were significantly lower than those of the group fed with wild-type L. casei or placebo (P < 0.01). Histopathological analyses of the small intestine, showed both decreased intestinal injury and increased villi length were observed in the mice fed with rhLF/L. casei as compared with the control groups (P < 0.01). Our results demonstrate that L. casei expressing hLF exhibited antibacterial activity both in in vitro and in vivo. It also provides a potentially large-scale production of hLF as applications for treatment of infections caused by clinically relevant pathogens