Preparation of selective and segmentally labeled single-stranded DNA for NMR by self-primed PCR and asymmetrical endonuclease double digestion

We demonstrate a new, efficient and easy-to-use method for enzymatic synthesis of (stereo-)specific and segmental 13C/15N/2H isotope-labeled single-stranded DNA in amounts sufficient for NMR, based on the highly efficient self-primed PCR. To achieve this, new approaches are introduced and combined. (i) Asymmetric endonuclease double digestion of tandem-repeated PCR product. (ii) T4 DNA ligase mediated ligation of two ssDNA segments. (iii) In vitro dNTP synthesis, consisting of in vitro rNTP synthesis followed by enzymatic stereo-selective reduction of the C2′ of the rNTP, and a one-pot add-up synthesis of dTTP from dUTP. The method is demonstrated on two ssDNAs: (i) a 36-nt three-way junction, selectively 13C9/15N3/2H(1′,2″,3′,4′,5′,5″)-dC labeled and (ii) a 39-nt triple-repeat three-way junction, selectively 13C9/15N3/2H(1′,2″,3′,4′,5′,5″)-dC and 13C9/15N2/2H(1′,2″,3′,4′,5′,5″)-dT labeled in segment C20-C39. Their NMR spectra show the spectral simplification, while the stereo-selective 2H-labeling in the deoxyribose of the dC-residues, straightforwardly provided assignment of their C1′–H2′ and C2′–H2′ resonances. The labeling protocols can be extended to larger ssDNA molecules and to more than two segments

Raman terahertz Si:P and Si:Sb lasers

In the past few years significant progress has been made towards silicon-based lasers mainly due to new approaches in the infrared wavelength range, such as silicon nanocrystals, A-centre mediated direct recombination, Si/SiO2 and Si/SiGe superlattices, porous silicon, erbium-doped silicon, silicon light-emitting diodes, as well as 1.67 µm Raman silicon laser. Recently achieved optically pumped silicon terahertz lasers involve light scattering at donor centre states coupled by resonant interaction with an intervalley transverse acoustic g-TA phonon in silicon. Raman-type Stokes stimulated emission has been obtained from silicon crystals doped by antimony and phosphorus donors at low temperatures when optically excited by radiation from a tunable infrared free electron laser. The photon energy of the terahertz laser emission is equal to the pump photon energy reduced by the energy spacing between a singlet and a doublet donor states in silicon. The lasers emit a few tenths of mWs in a few ps pulse in the frequency ranges of 4.6 - 5.8 THz (Si:Sb) and 6.0 - 6.4 THz (Si:P) and have a gain of ~10^-3 1/cm at a pump intensity of ~100 kW/cm2. Raman-type silicon lasers based on a light scattering on donor centres can be potentially expanded onto mid-infrared lasing, where they could have higher gain and operation temperatures

Treatment adherence in schizophrenia : A patient-level meta-analysis of combined CATIE and EUFEST studies

The Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) obtained a sample of 1493 chronic schizophrenia patients. The European First Episode Schizophrenia Trial (EUFEST) studied a sample of 498 patients. We have combined these two samples to study the predictors and correlates of adherence to treatment. Here we report on adherence to pharmacological treatment at the six and twelve month assessments of these trials with a combined subsample of 1154 schizophrenia patients. Individual patients[U+05F3] data were used for analyses. We used logistic regression to examine the effects of substance use, akathisia, parkinsonism, dyskinesia, hostility, and insight on pharmacological adherence. The results showed that reduced adherence to pharmacological treatment was associated with substance use (p = 0.0003), higher levels of hostility (p = 0.0002), and impaired insight (p < 0.0001). Furthermore, poor adherence to study medication was associated with earlier discontinuation in the combined data. The clinical implications of the results point to the importance of routine assessments and interventions to address patients[U+05F3] insight and comorbid substance use and the establishment of therapeutic alliance