Effect of the P/Al Molar Ratio and Heating Rate on the Composi-Tion of Alumino-Phosphate Binders

New insights into the chemistry of alumino-phosphate solutions are provided in this contribution. In a first part, a solution with a P/Al molar ratio of 3.2 was prepared for the first time. The binders obtained at 500 and 700 °C were compared to those obtained with the 3 and 3.5 P/Al molar ratio solutions in order to determine the impact of moderate P₂O₅ excess on the final phosphate ceramic nature. In a second part, the widely used P/Al = 3 solution was heat-treated at 500 °C using different heating rates (0.2, 1, and 10 °C/min) to determine how this parameter modifies the final phosphate ceramic composition. Our data show that moderate P₂O₅ excess is sufficient to obtain binders with a high amount of stable cubic aluminium metaphosphate compound at 700 °C but not at 500 °C, where significant P₂O₅ excess is mandatory. We also show that slow heating favors the formation of cubic aluminium metaphosphate compound at 500 °C.     

Differences in the Spinal Command of Ejaculation in Rapid Ejaculating Rats

IntroductionIt has been hypothesized that lifelong premature ejaculation is part of a biological variation in the intravaginal ejaculation latency, but what causes this variation remains poorly understood.AimThe aim of this study is to elucidate whether variations in ejaculation latencies in an experimental rat model for premature ejaculation are linked to differences in the spinal command of ejaculation.Main Outcome MeasuresElectrical microstimulation of the spinal generator for ejaculation revealed an accelerated expulsion phase in rapid ejaculating rats.MethodsAdult male Wistar rats were categorized as “sluggish,”“normal,” or “rapid” ejaculators on the basis of their ejaculation frequency in sexual mating tests. One to three weeks after selection, males were urethane anesthetized and electrically microstimulated in the spinal generator for ejaculation, evoking ejaculation. Bulbospongiosus muscle electromyographic and intraluminal vas deferens pressure were measured simultaneously, representing, respectively, the expulsion and emission phase in ejaculation.ResultsElectrical microstimulation of the spinal generator for ejaculation evoked ejaculation in “sluggish” (N = 9), “normal” (N = 13), and “rapid” (N = 11) ejaculating rats. Vas deferens contraction (emission phase) was evoked at different stimulation strengths, but response properties were not statistically different between “sluggish,”“normal,” and “rapid” ejaculator rats. Bulbospongiosus muscle contractions (expulsion phase) following microstimulation was significantly accelerated in “rapid” rats as compared with “sluggish” and “normal” rats. The total duration of bulbospongiosus muscle contractions remained unchanged between the three ejaculator groups.ConclusionsOur results provide the first scientific evidence supporting a neurophysiological difference between “rapid,”“normal,” and “sluggish” ejaculators, expressed as an accelerated expulsion phase in “rapid” ejaculator rats. This bridges the gap between a sexual behavior trait and the spinal command of ejaculation. Borgdorff A, Rössler A-S, Clément P, Bernabé J, Alexandre L, and Giuliano F. Differences in the spinal command of ejaculation in rapid ejaculating rats. J Sex Med 2009;6:2197–2205.     

A Novel Smartphone Accelerometer Application for Low-Intensity Activity and Energy Expenditure Estimations in Overweight and Obese Adults

Physical inactivity and sedentary behaviors are on the rise worldwide and contribute to the current overweight and obesity scourge. The loss of healthy life style benchmarks and the lack of the need to move make it necessary to provide feedback about physical and sedentary activities in order to promote active ways of life. The aim of this study was to develop a specific function adapted to overweight and obese people to identify four physical activity (PA) categories and to estimate the associated total energy expenditure (TEE). This function used accelerometry data collected from a smartphone to evaluate activity intensity and length, and TEE. The performance of the proposed function was estimated according to two references (Armband® and FitmatePro®) under controlled conditions (CC) for a 1.5-h scenario, and to the Armband® device in free-living conditions (FLC) over a 12-h monitoring period. The experiments were carried out with overweight and obese volunteers: 13 in CC and 27 in FLC. The evaluation differences in time spent in each category were lower than 7% in CC and 6% in FLC, in comparison to the Armband® and FitmatePro® references. The TEE mean gap in absolute value between the function and the two references was 9.3% and 11.5% in CC, and 8.5% according to Armband® in FLC.     

Effect of Dapoxetine on Ejaculatory Performance and Related Brain Neuronal Activity in Rapid Ejaculator Rats

IntroductionA brain network specifically activated when ejaculation occurs has been described in rats. Increasing serotonin (5‐hydroxytryptamine [5‐HT]) tone impairs ejaculation and chronic 5‐HT selective serotonin reuptake inhibitors (SSRIs) are known to inhibit ejaculation. However, efficacy of acute treatment with SSRI varies from one compound to another. The SSRI dapoxetine has been reported to delay ejaculation when given on demand to men with premature ejaculation (PE), although the mechanism of action is unclear. Effects of acute SSRIs on activity of the brain ejaculation circuit in relation with ejaculation have never been examined.AimTo test the effects of acute administration of the short half‐life SSRI dapoxetine on ejaculatory performance and activity in brain ejaculation circuit in rapid ejaculator rats taken as PE model.MethodsStandard copulatory test was used to attribute one sexual category (sluggish, middle, or rapid) to male rats on the basis of their ejaculatory performance. Parameters of sexual, including ejaculatory, behavior, and Fos level of expression in discrete brain areas were assessed in the three sexual categories and in rapid category following acute oral treatment with dapoxetine.Main Outcome MeasuresEjaculation frequency (EF) and latency (EL) were measured as primary end points of ejaculatory behavior. Density of Fos‐immunopositive cells in specific brain areas of brain stem, hypothalamus, and thalamus was determined as marker of neuronal activity.ResultsEL and Fos level of expression in hypothalamic and thalamic structures were found related. Dapoxetine acute oral administration (300 mg/kg) to rapid ejaculator rats resulted in (i) diminution of ejaculatory performance (lengthened EL and decreased EF); and (ii) modulation of Fos level of expression in hypothalamic and thalamic nuclei of the brain ejaculatory circuit.ConclusionAcute treatment with dapoxetine, which reduced ejaculatory performance in rapid ejaculator rats, was also accompanied with changes in neuronal activity in components of the brain ejaculatory network. Clément P, Laurin M, Compagnie S, Facchinetti P, Bernabé J, Alexandre L, and Giuliano F. Effect of dapoxetine on ejaculatory performance and related brain neuronal activity in rapid ejaculator rats. J Sex Med **;**:**–**.     

Determination of vitamin D3 and 25-hydroxyvitamin D3 in foodstuffs by HPLC UV-DAD and LC–MS/MS

In order to generate new data for vitamin D content for the Canadian Nutrient File, a method for the quantification of vitamin D₃ and 25(OH)D₃ in foodstuffs has been modified and improved. Vitamin D₃ was quantified using reverse phase liquid chromatography (LC) with UV-diode array detector (UV-DAD), while 25(OH)D₃ was measured by triple quadrupole mass spectrometry (APCI MS/MS). Quantification was by internal standards (IS) using vitamin D₂ and 25(OH)D₂. A Certified Reference Material (CRM-421 containing vitamin D₃) and a control sample (internally generated reference material of ground pork containing both vitamin D₃ and 25(OH)D₃) were used as validation and quality control tools. Limit of detection for both compounds was 0.04 μg/100 g. Accuracy for vitamin D in the CRM-421 was 99% (0.142 mg/kg for a target of 0.143, n = 10). Recovery of vitamin D₃ in ground pork was 97% (88% absolute recovery). For 25(OH)D₃, a recovery of 94% (73% absolute recovery) was obtained. Using this method, data for vitamin D₃ and 25(OH)D₃ content in a variety of foods (pork, beef, eggs, poultry, fish, and dinners) have been generated.