Microstructure and 13c-nuclear magnetic relaxation of bacterial poly (b-hydroxyalkanoates)

A new method for the determination of the composition of poly($beta$-hydroxybutyrate-co-$beta$-hydroxyvalerate) (P(HB-co-HV)) copolyesters, by using optical rotation dispersion (ORD) spectra, was proposed. A linear equation based on the "optical superposition principle" has been shown to relate the specific rotation ($alpha$) of P(HB-co-HV) samples with their content of $beta$-hydroxyvalerate determined by $sp1$H NMR.The microstructure of P(HB-co-HV) copolymers, based on fast atom bombardment mass spectrometry (FAB-MS) analysis of the partial methanolysis or ammonolysis products, is described. The interpretation of the data indicated that the sequence distribution of all samples were statistically random (Bernoullian model), and permitted the detection in one sample of traces of pure poly($beta$-hydroxybutyrate), PHB.$sp{13}$C spin-lattice relaxation times and NOE were measured as a function of temperature in two magnetic fields, for poly ($beta$-hydroxybutyrate) in chloroform-d and 1,1,2,2,-tetrachloroethane-d$sb2$ (TCE). Among the various dynamic models used for the interpretation of the data, the Dejean-Laupretre-Monnerie (DLM) model offered the best description of the segmental motion along the PHB chain

Post operative stereotactic radiosurgery for positive or close margins after preoperative chemoradiation and surgery for rectal cancer

Background: The incidence of positive margins after neoadjuvant chemoradiation and adequate surgery is very low. However, when patients do present with positive or close margins, they are at a risk of local failure and local therapy options are limited. We evaluated the role of stereotactic body radiotherapy (SBRT) in patients with positive or close margins after induction chemoradiation and total mesorectal excision

Stereotactic Body Radiotherapy (SBRT) Reirradiation for Pelvic Recurrence From Colorectal Cancer

Background and ObjectivesWhen surgery is not adequate or feasible, stereotactic body radiotherapy (SBRT) reirradiation has been used for recurrent cancers. We report the outcomes of a series of patients with pelvic recurrences from colorectal cancer reirradiated with SBRT

Patterns of Care for Non–Small-Cell Lung Cancer at an Academic Institution Affiliated With a National Cancer Institute–Designated Cancer Center

These data point toward the need for improved evidence-based use of resources in the third-line setting of stage IV NSCLC