Urological outcomes following pelvic exenteration for non-urological malignancies.

Background: Pelvic exenteration (PE) is a major surgical procedure used as a salvage therapy for patients with locally advanced or recurrent pelvic malignancies. Urinary reconstruction is a major part of PE and is often associated with high rates of post-operative complications. In the current study we evaluate the short and long-term urological outcomes following PE for Colo-Rectal (CR) and gyneco-oncological (GO) malignancies. Methods: Study included 22 patients who underwent PE for recurrent or locally advanced CR and GO malignancies in our institution between the years 2010-2018. The endpoint was post-operative freedom from urological complications. Results: Of 22 patients included, 13 (59 %) and 9 (41 %) underwent PE for CR and GO malignancies respectively. The mean age of the patients was 54 years. The median follow-up was 19 months. Seven (78 %) patients with GO malignancy and 11 (85 %) with CR malignancy underwent PE for local recurrence. Hydronephrosis prior to surgery existed in 8 (36.3 %) patients, of which, 5 patients required kidney drainage via nephrostomy tube. Two patients underwent posterior pelvic exenteration (PPE) with bladder preservation whereas the remaining 20 underwent cystectomy with urinary diversion by ileal conduit. Hydronephrosis post PE developed in 13 patients (59 %). eight (36 %) patients needed kidney drainage by nephrostomy tubes post PE, of these, 6 (75 %) had disease recurrence. The 2 years freedom from kidney drainage was 68 %, however the median time for kidney drainage was 0.5 months. The median overall survival was 12.5 months. Conclusion: The rate of urological complications following PE is relatively high and associated with disease recurrence.

Ultrafast intersystem-crossing in platinum containing π-conjugated polymers with tunable spin-orbit coupling.

The development of efficient organic light-emitting diodes (OLED) and organic photovoltaic cells requires control over the dynamics of spin sensitive excitations. Embedding heavy metal atoms in π-conjugated polymer chains enhances the spin-orbit coupling (SOC), and thus facilitates intersystem crossing (ISC) from the singlet to triplet manifolds. Here we use various nonlinear optical spectroscopies such as two-photon absorption and electroabsorption in conjunction with electronic structure calculations, for studying the energies, emission bands and ultrafast dynamics of spin photoexcitations in two newly synthesized π-conjugated polymers that contain intrachain platinum (Pt) atoms separated by one (Pt-1) or three (Pt-3) organic spacer units. The controllable SOC in these polymers leads to a record ISC time of <~1 ps in Pt-1 and ~6 ps in Pt-3. The tunable ultrafast ISC rate modulates the intensity ratio of the phosphorescence and fluorescence emission bands, with potential applications for white OLEDs.

Below-gap excitation of pi-conjugated polymer-Fullerene blends: implications for bulk organic heterojunction solar cells.

We used a variety of optoelectronic techniques such as broadband fs transient and cw photomodulation spectroscopies, electroabsorption, and short-circuit photocurrent in bulk heterojunctions organic solar cells for studying the photophysics in pi-conjugated polymer-fullerene blends with below-gap excitation. In contrast to the traditional view, we found that below-gap excitation, which is incapable of generating intrachain excitons, nevertheless efficiently generates polarons on the polymer chains and fullerene molecules. The polaron action spectrum extends deep inside the gap as a result of a charge-transfer complex state formed between the polymer chain and fullerene molecule. With appropriate design engineering the long-lived polarons might be harvested in solar cell devices.