The purpose of this study is to evaluate the dosimetric accuracy of MRI-based treatment planning for prostate cancer using a commercial radiotherapy treatment planning system. Three-dimensional conformal plans for 15 prostate patients were generated using the AcQPlan system. For each patient, dose distributions were calculated using patient CT data with and without heterogeneity correction, and using patient MRI data without heterogeneity correction. MR images were post-processed using the gradient distortion correction (GDC) software. The distortion corrected MR images were fused to the corresponding CT for each patient for target and structure delineation. The femoral heads were delineated based on CT. Other anatomic structures relevant to the treatment (i.e., prostate, seminal vesicles, lymph notes, rectum and bladder) were delineated based on MRI. The external contours were drawn separately on CT and MRI. The same internal contours were used in the dose calculation using CT- and MRI-based geometries by directly transferring them between MRI and CT as needed. Treatment plans were evaluated based on maximum dose, isodose distributions and dose-volume histograms. The results confirm previous investigations that there is no clinically significant dose difference between CT-based prostate plans with and without heterogeneity correction. The difference in the target dose between CT- and MRI-based plans using homogeneous geometry was within 2.5%. Our results suggest that MRI-based treatment planning is suitable for radiotherapy of prostate cancer.

No abstract

This review highlights transformation networks created with coordination cages. Such synthetic stimuli-controlled networks can help elucidate biological signal transduction, as well as enabling new functions and applications.

The compounds, TiO 2 -1 & -2 were synthesized by 0.5 M NaNO 3 : 0.5 M KNO 3 (I) and 0.88 M LiNO 3 :0.12 MLiCl (II) salts at 510 • C and 280 • C, resp.., XRD studies show single anatase phase with characteristic tetragonal lattice parameter values of a ∼3.78 Å and c ∼ 9.51 Å. The TEM images show aggregates of 10-30 nm sized nanosquares (TiO 2 -1) and spherical particles (TiO 2 -2). Surface area of the TiO 2 powders were 74 and 200 m 2 g −1 , resp. for 1 and 2. Upon heat-treatment (TiO 2 -2) from 500 • C to 850 • C, the surface area decreases from 80 to 0.7 m 2 g −1 . Cyclic voltammetry studies show cathodic and anodic peaks at ∼1.7 and ∼ 2.0 V, resp. for both bare and heat treated TiO 2 up to 750 • C. Galvanostatic cycling studies show that the first discharge-charge capacity values are 244 and 198 (±3) mAh g −1 resp. for TiO 2 -1 at a current of 33 mA g −1 in the voltage window, 1.0-2.8 V vs. Li/Li + . TiO 2 -2 nanoparticles show a less capacity fade during cycling and delivered first discharge-charge capacity values of 340 and 253 (±3) mAh g −1 , resp. at a current rate of 33 mA g −1 . The effects of heat-treatment and Li-cycling at a cutoff voltage (0.005 V) were studied and discussed reaction mechanism.

Chemical purifications are critical processes across many industries, requiring 10–15% of humanity’s global energy budget. Coordination cages are able to catch and release guest molecules based upon their size and shape, providing a new technological basis for achieving chemical separation. Here, we show that aqueous solutions of Fe II 4 L 6 and Co II 4 L 4 cages can be used as liquid membranes. Selective transport of complex hydrocarbons across these membranes enabled the separation of target compounds from mixtures under ambient conditions. The kinetics of cage-mediated cargo transport are governed by guest binding affinity. Using sequential transport across two consecutive membranes, target compounds were isolated from a mixture in a size-selective fashion. The selectivities of both cages thus enabled a two-stage separation process to isolate a single compound from a mixture of physicochemically similar molecules.