A new modular approach to nanoassembly: stable and addressable DNA nanoconstructs via orthogonal click chemistries.

Thermodynamic instability is a problem when assembling and purifying complex DNA nanostructures formed by hybridization alone. To address this issue, we have used photochemical fixation and orthogonal copper-free, ring-strain-promoted, click chemistry for the synthesis of dimeric, trimeric, and oligomeric modular DNA scaffolds from cyclic, double-stranded, 80-mer DNA nanoconstructs. This particular combination of orthogonal click reactions was more effective for nanoassembly than others explored.

I-125 seed planning: an alternative method of urethra definition.

Background And Purpose: To investigate the use of aerated aqueous gel rather than a catheter to define the urethra during permanent I-125 seed implant planning.

Materials And Methods: Twenty patients were treated between September 2007 and March 2008, each having two sequential volume studies: one visualizing the urethra with a catheter and the other using aerated gel. Two individually optimised plans were produced for each patient: one from the gel and the other from the catheter image set, and the plans were analysed dosimetrically.

Radiation dose, chemotherapy and risk of soft tissue sarcoma after solid tumours during childhood.

Soft tissue sarcoma (STS) is one of the most frequent second primary cancer that occurs during the first 20 years following treatment for a solid cancer in childhood. Our aim was to quantify the risk of STS as a second malignant neoplasm and to investigate its relationship with radiotherapy and chemotherapy. A cohort study of 4,400 3-year survivors of a first solid cancer diagnosed during childhood in France or the United Kingdom, between 1942 and 1985, was followed 15 years on average.

Brachytherapy of glioblastoma recurring in previously irradiated territory: predictive value of tumor volume.

Purpose: To evaluate the impact of tumor volume on survival of patients reirradiated with (192)Ir for recurrent glioblastoma.

Methods And Materials: Between 1993 and 1997, 42 patients with recurrent glioblastomas (29 males and 13 females, age 18-69 years, median age 49) were treated with (192)Ir implantation. Previous treatments included surgery, external beam radiotherapy, and chemotherapy.