连续波锁模P_r~（3＋）：YLF激光器

本文报导了采用氩离子激光器来泵浦Ｒｒ￣（３＋）：ＹＬＦ晶体，应用声光调制器实现了主动锁模；同时应用振动─高反射平面镜也实现了被动锁模，两种锁模均得到了ｐｓ光脉冲。据作者了解这是这种晶体材料的第一次锁模运转。     

Plant delta(15)N associated with arbuscular mycorrhization, drought and nitrogen deficiency

It has long been evident that plant (15)N chiefly reflects the processes which fractionate (15)N/(14)N rather than the (15)N of plant N source(s). It has emerged recently that one of the most important fractionating processes contributing to the whole plant (15)N is the presence/absence, type or species of mycorrhiza, especially when interacting with nutrient deficiency. Ecto- and ericoid mycorrhizas are frequently associated with (15)N-depleted foliar (15)N, commonly as low as -12 per thousand. As shown by the present study, plants having no mycorrhiza, or those infected with various species of arbuscular mycorrhiza (AM)-forming fungi, interact with varying concentrations of soil nitrogen [N] and moisture to enrich plant (15)N by as much as 3.5 per thousand. Hence the lack of a mycorrhiza, or variation in the species of AM-forming fungal associations, can account for about 25% of the usually reported variations of foliar (15)N found in field situations and do so by (15)N enrichment rather than depletion. Copyright 1999 John Wiley & Sons, Ltd.     

Entropic stochastic resonance

We present a novel scheme for the appearance of stochastic resonance when the dynamics of a Brownian particle takes place in a confined medium. The presence of uneven boundaries, giving rise to an entropic contribution to the potential, may upon application of a periodic driving force result in an increase of the spectral amplification at an optimum value of the ambient noise level. The entropic stochastic resonance, characteristic of small-scale systems, may constitute a useful mechanism for the manipulation and control of single molecules and nanodevices.     

New insight into the DNA binding studies,In-Vitro anti-cancer activity and molecular modelling of dioxo complexes of Molybdenum(VI) and Tungsten(VI) hydroxamic acids

The present study embodies the detail of interaction of Complex 1, Bis(N-phenyl-o-methoxybenzohydroxamato)Molybdenum(VI): [N-PMBHA-Mo(VI)] and Complex 2, Bis(N-phenylbenzohydroxamato)Tungsten(VI): [N-PBHA-W(VI)] with ct-DNA (Calf thymus-DNA) and its consequences by UV–Visible absorption spectroscopy, fluorescence spectroscopy, three-dimensional fluorescence spectroscopy, viscosity measurements and molecular docking. The intrinsic binding constant, K_b of complexes were determined which follows the order as complex 1 > complex 2 along with variation in shift and intensity for the complexes. Fluorescence spectroscopy applied for the determination of Stern–Volmer quenching constant, binding constant and the number of binding sites which reveals groove mode of binding. Non-radiative energy transfer between donor and acceptor molecule exposed by Förster energy transference theory (FRET) studies. The increase in the relative viscosity of ct-DNA with increasing the concentration of the complex 1 and complex 2 is also revealed. FTIR analysis also revealed that both the complexes interacted positively with bases and phosphates of ct-DNA. The docking studies complemented the experimental results revealing minor groove mode of binding for both the complexes. Finally, the in-vitro cytotoxicity studies indicate that the complexes have excellent anticancer activity against the breast cancer cell line, MCF-7, which could be a constructive guideline to produce new generations of anticancer agents.