The effectiveness of a standardized tobacco cessation program on psychophysiological parameters in patients with addiction undergoing long-term rehabilitation: a quasi-experimental pilot study.

BACKGROUND: Although there is a very high comorbidity between tobacco dependence and other addictive disorders, there are only few studies examining the implementation and outcomes of a tobacco cessation program in patients with addictive diseases. Therefore, the aim of this study is to investigate to what extent a standardized tobacco cessation program leads to improvements regarding psychological/physical parameters in patients with addiction undergoing therapy and whether there is a reduction in tobacco consumption. METHODS: The study took place in a therapeutic community specialized in addiction therapy. A total sample of 56 participants were non-randomly assigned to an intervention group (IG; n = 31) and a treatment as usual group (TAUG; n = 25). The IG participated in a 6-week tobacco cessation program, while the TAUG received no additional treatment. Both groups were assessed for changes in primary outcomes (tobacco dependence, smoked cigarettes per day (CPD), and general substance-related craving) and secondary outcomes (heart rate variability (HRV): root mean square of successive differences, self-efficacy, and comorbid psychiatric symptoms) at two measurement time points (pre- and post-treatment/6 weeks). RESULTS: We observed significant improvements in self-efficacy (F(1,53) = 5.86; p < .05; ηp2 = .11) and decreased CPD in the IG (ß = 1.16, ρ < .05), while no significant changes were observed in the TAUG. No significant interaction effects were observed in psychiatric symptoms, general substance-related craving, and HRV. CONCLUSIONS: The results highlight the potential benefit of an additional tobacco cessation program as part of a general addiction treatment. Although no improvements in the physiological domain were observed, there were significant improvements regarding self-efficacy and CPD in the IG compared to the TAUG. Randomized controlled trials on larger samples would be an important next step. TRIAL REGISTRATION: ISRCTN15684371.

Dynamic multimode analysis of Q-switched solid state laser cavities.

We derive a new model and simulation technique called "Dynamic Multimode Analysis (DMA)" to simulate the 3-dimensional dynamic behavior of a laser. A Gaussian mode analysis is used to obtain resonator eigenmodes taking into account thermal aberrations. These modes are coupled by a set of rate equations to describe the dynamic behavior of the individual modes for cw and Q-switched lasers. Our approach analyzes mode competition and provides a detailed description of the laser beam in terms of output power, beam quality factor M(2), and pulse shape. Comparison of experimental data with our simulation results provides new insight into the effect of mode competition and the operation of Q-switched lasers.

Cytosine methylation inhibits replication of African cassava mosaic virus by two distinct mechanisms.

Extrachromosomally replicating viral DNA is usually free of cytosine methylation and viral templates methylated in vitro are poor substrates when used in replication assays. We have investigated the mechanism of inhibition of viral replication by DNA methylation using as a model the DNA A of African cassava mosaic virus. We have constructed two component helper systems which allow for separation of the transcriptional inhibition of viral genes necessary for replication from replication inhibition due to altered interaction between the replication complex and methylated viral DNA. Our results suggest that methylation-mediated reduction of viral replication is due to both repression mechanisms and that this provides two independent selection pressures for the maintenance of methylation-free replicons in infected cells.