Tunable, coherent optical comb source via on-chip bidirectional coupling.

A tunable comb source is demonstrated through gain switching on a three-sectioned photonic integrated circuit (PIC). The PIC consists of two mutually coupled lasers connected by a passive waveguide. One of these is a tunable, two-section, single mode laser. The second laser is a simple Fabry-Perot cavity laser which can be phase-locked with the single mode laser via bidirectional coupling. Frequency combs are produced by gain switching the Fabry-Perot laser by applying a high-power radio frequency signal. Combs are generated with line spacings ranging from 3.5 to 8 GHz. The on-chip bidirectional coupling causes the comb to also be generated in the two-section device. Despite the lack of on-chip optical isolation between the lasers, the resulting combs are stable. Numerical simulations using a delay-differential model reproduce the results and reveal the important role played by the short delay times inherent to on-chip integration in this stability.

Effects of Viola odorata as an Add-On Therapy on Insomnia in Patients with Obsession or Depression: A Pilot Randomized Double-Blind Placebo-Controlled Trial.

Objective: The present study was conducted to investigate the effect of Viola odorata extracted syrup on the quality and patterns of sleep in patients with depression or obsessive-compulsive disorder (OCD) as add-on therapy. Design: A pilot double-blind randomized placebo-controlled trial. Settings/Location: Psychiatric Clinic of Imam Hossein Hospital, Tehran, Iran. Subjects: Participants were 16-15 years of age with mild and moderate depression or OCD having insomnia. Interventions: This pilot study was conducted on patients with insomnia divided into two groups with depression (40 patients) or OCD (43 patients). Each group randomly assigned into two arms with the same conditions at baseline. The intervention arm daily received 5 mL V. odorata syrup every 12 h for 4 weeks, and the control arm received 5 mL placebo syrup every 12 h for 4 weeks. None of the participants was deprived of their routine treatment for depression or OCD. Outcome measures: The scores of insomnia symptoms were evaluated using total score of the Pittsburgh Sleep Quality Index (PSQI) and the scores of its components, the depression score using the final Beck depression inventory-II (BDI-II) score, and OCD score using the Yale-Brown Obsessive-Compulsive Scale (YBOCS). Results: The total PSQI score was found to be improved significantly in the intervention arms with depression or OCD (p < 0.001) compared with the corresponding control arms. Significant improvements were also observed in the final mean difference of BDI-II (p = 0.009) and YBOCS (p = 0.001) scores in the intervention arms. Conclusions: V. odorata syrup significantly improved insomnia symptoms and the scores of depression and OCD.

Organo-arsenic molecular layers on silicon for high-density doping.

This article describes for the first time the controlled monolayer doping (MLD) of bulk and nanostructured crystalline silicon with As at concentrations approaching 2 × 10(20) atoms cm(-3). Characterization of doped structures after the MLD process confirmed that they remained defect- and damage-free, with no indication of increased roughness or a change in morphology. Electrical characterization of the doped substrates and nanowire test structures allowed determination of resistivity, sheet resistance, and active doping levels. Extremely high As-doped Si substrates and nanowire devices could be obtained and controlled using specific capping and annealing steps. Significantly, the As-doped nanowires exhibited resistances several orders of magnitude lower than the predoped materials.

Synthesis and characterization of a series of transition metal complexes with a new symmetrical polyoxaaza macroacyclic Schiff base ligand: X-ray crystal structure of cobalt(II) and nickel(II) complexes and their antibacterial properties.

A new symmetrical [N4O2] hexadentate Schiff base ligand, (E)-N-(pyridin-2-ylmethylene)-2-(3-(2-((E)-pyridin-2-lmethyleneamino)phenoxy)naphthalen-2-yloxy)benzenamine, abbreviated to L, and its complexes of Ni(II), Cu(II), Zn(II), Co(II), Cd(II) and Mn(II) have been synthesized in the presence of metal ions. The complexes were structurally characterized by elemental analyses, IR, UV-Vis, NMR and molar conductivity. The crystal structures of two complexes, [NiL(ONO2)2]·2H2O and [CoLCl2]CH3OH·0.5H2O, have been determined by a single crystal X-ray diffraction study. In these complexes, the ligand is coordinated in a neutral form via pyridine and azomethine nitrogen atoms. The metal ions complete their six coordination with two coordinated nitrate or chloride ions, forming a distorted octahedral geometry. The synthesized compounds have antibacterial activity against the three Gram-positive bacteria: Enterococcus faecalis, Bacillus cereus and Staphylococcus epid and also against the three Gram-negative bacteria: Citrobacter freundii, Enterobacter aerogenes and Salmonella typhi. The activity data show that the complexes are more potent antibacterials than the parent Schiff base.