Anomalous staged hot-electron acceleration by two-plasmon decay instability in magnetized plasmas.

We present a staged hot-electron acceleration mechanism of the two-plasmon decay (TPD) instability in the transverse magnetic field under the parameters relevant to inertial confinement fusion experiments. After being accelerated by the forward electron plasma wave (FEPW) of TPD, the hot-electrons can be anomalously accelerated again by the backward electron plasma wave (BEPW) of TPD and then obtain higher energy. Moreover, the surfatron acceleration mechanism of TPD in the magnetic field is also confirmed, the electrons trapped by the TPD daughter EPWs are accelerated in the direction along the wave front. Interestingly, the velocity of electrons accelerated by surfing from the FEPW is quite easily close to the BEPW phase velocity, which markedly enhances the efficiency of the staged acceleration. The coexistence of these two acceleration mechanisms leads to a significant increase of energetic electrons generated by TPD in the magnetic field. Meanwhile the EPWs are dissipated, TPD instability is effectively suppressed, and the laser transmission increases.

Kinetic model and Vlasov simulation verification of two-ion decay instability.

A kinetic theory is developed to describe the longitudinal decay of two-ion decay (TID): The pump ion-acoustic wave (IAW) decays into two daughter IAWs with a longer wavelength. The instability growth rate and threshold are given by the theory. Both the simulations of full kinetic Vlasov and hybrid Vlasov (kinetic ions and Boltzmann electrons) are employed to verify the theory and have a high quantitative agreement with the theory for 8≤ZT_{e}/T_{i}≤15, where Z is the ion charge number and T_{i}(T_{e}) is the ion (electron) temperature. The kinetic model developed here solves a long-standing problem that the simple fluid theory underestimates growth rate by a factor of 2∼3. Also, a reasonable explanation is given to the typical characteristics of TID that the dependence curves of subharmonic growth rate γ and wave number k.

Effect of desvenlafaxine on mood and climacteric symptoms in menopausal women with moderate to severe vasomotor symptoms.

OBJECTIVE: To assess effects of desvenlafaxine (administered as desvenlafaxine succinate) on secondary outcomes of mood, climacteric symptoms, and treatment satisfaction in postmenopausal women with moderate to severe menopausal vasomotor symptoms (VMS). METHODS: A 12-week, multicenter, double-blind, placebo-controlled trial was conducted in postmenopausal women with ≥ 50 moderate to severe hot flushes per week. Participants were randomly assigned to desvenlafaxine 100 mg/day, desvenlafaxine 150 mg/day, or placebo. Secondary outcome efficacy variables included Profile of Mood States (POMS), Greene Climacteric Scale (GCS), and Menopausal Symptoms Treatment Satisfaction Questionnaire (MS-TSQ) scores. Change from baseline in POMS total mood disturbance (TMD) score and subdomain scores were evaluated using analysis of covariance, adjusting for treatment and study site as factors and baseline score. GCS total and subdomain scores were analyzed similarly. Treatment satisfaction was analyzed using the row mean score test. RESULTS: A total of 458 women were enrolled. At week 12, desvenlafaxine 100 mg/day significantly improved POMS TMD scores (p <0.001) and four of six POMS subdomains compared with placebo (all p ≤ 0.005). Women taking desvenlafaxine 100 mg/day experienced significantly greater improvement in GCS total scores (p <0.001) and five of six subdomains (all p ≤ 0.029) compared with placebo. Treatment with desvenlafaxine 100 mg/day resulted in significantly greater treatment satisfaction overall and in six of seven additional MS-TSQ items (all p ≤0.042). Desvenlafaxine 150-mg/day results were similar. CONCLUSIONS: Desvenlafaxine treatment improved mood and climacteric symptoms in postmenopausal women with moderate to severe VMS compared with placebo, and more women were satisfied with desvenlafaxine treatment than with placebo.

Randomized placebo- and active-controlled study of desvenlafaxine for menopausal vasomotor symptoms.

OBJECTIVE: To evaluate the efficacy and safety of desvenlafaxine (administered as desvenlafaxine succinate) vs. tibolone and placebo for menopausal vasomotor symptoms and the incidence of uterine bleeding. METHODS: This 12-week, double-blind, randomized, controlled trial was conducted at 35 sites in Europe, two sites in South Africa, and one site in Mexico. Postmenopausal women with ≥50 moderate or severe hot flushes per week (n = 485) were randomized to desvenlafaxine 100 mg/day, tibolone 2.5 mg/day, or placebo. Reduction in the average daily number of moderate and severe hot flushes at weeks 4 and 12 (primary endpoint) was evaluated using analysis of covariance. Safety assessments included incidence of uterine bleeding, adverse events, laboratory values, and vital signs. RESULTS: At week 12, no statistically significant difference was observed in reduction of the average daily number of moderate and severe hot flushes for desvenlafaxine (-5.78) vs. placebo (-5.82; p = 0.921), although time to 50% reduction was significantly less than placebo (13 vs. 26 days, p = 0.006). Hot flush reduction with tibolone (-8.21) was significantly greater than placebo (p < 0.001). Nausea was the most common adverse event with desvenlafaxine, was generally mild to moderate, and resolved within the first 2 weeks. Significantly more subjects experienced bleeding with tibolone (23%) vs. desvenlafaxine (12%; p < 0.024) or placebo (9%; p < 0.001). CONCLUSIONS: Desvenlafaxine did not separate from placebo in reducing the number of moderate to severe hot flushes at week 12, although it did allow women to achieve 50% reduction sooner than placebo. Tibolone did separate from placebo, but with smaller than expected effect. The placebo effect was high (57%). Adverse drug reactions were consistent with the known safety profile of desvenlafaxine, and significantly more women who received tibolone experienced episodes of bleeding compared with women who received desvenlafaxine or placebo.

Water drop freezing: ejection of microdroplets.

The ejection of microdroplets from the surface of a freezing supercooled water drop has been observed and photographed. The fragmentation of a freezing drop in the forms of splintering, shattering, or bursting has been known for some time. This newly observed phenomenon of the ejection of numerous microdroplets, the duration of their ejection, and the electrical properties of these droplets suggest a possible mechanism of charge generation in thunderstorms.