Voluntary perioperative colorectal cancer registry from Kerala-An initial overview.

BACKGROUND: Although colorectal cancer (CRC) may not be uncommon in India, accurate data regarding its demographics and surgical outcomes is sparse. METHODS: With an aim to assess demographics and perioperative outcomes of CRC in Kerala, all members of Association of Surgical Gastroenterologists of Kerala (ASGK) were invited to participate in a registry. Data of operated cases of CRC were entered on a web-based questionnaire by participating members from January 2016. Analysis of accrued data until March 2018 was performed. RESULTS: From 25 gastrointestinal surgical centers in Kerala, 15 ASGK member hospitals contributed 1018 CRC cases to the database (M:F 621:397; median age-63.5 years [15-95 years]). Rectum (39.88%) and rectosigmoid (20.33%) cancers comprised the majority of the patients. Among them, preoperative bowel preparation was given to 37.68%, minimally invasive surgery (MIS) was performed in 73%, covering stoma in 47% and had an overall leak rate of 3.58%. In colonic malignancies, MIS was performed in 56.74%, covering stoma created in 13% and had a leak rate of 2.71%. Of 406 patients with rectal cancers, neo-adjuvant radiotherapy/chemoradiotherapy was given to 51.23%. The mean hospital stay for MIS in both rectal and colonic cancer patients was significantly shorter than open approach (10.46 ± 5.08 vs. 12.26 ± 6.03 days; p = 0.001and 10.29 ± 4.58 vs. 12.46 ± 6.014 days; p = <0.001). Mortality occurred in 2.2% patients. CONCLUSION: A voluntary non-funded registry for CRC surgery was successfully created. Initial data suggest that MIS was performed in majority, which was associated with shorter hospital stay than open approach. Overall mortality and leak rate appeared to be low.

A reusable surface-enhanced Raman scattering (SERS) substrate prepared by atomic layer deposition of alumina on a multi-layer gold and silver film.

A thermally stable, reusable surface-enhanced Raman scattering (SERS) substrate consisting of a gold/silver bi-layer film with a protective alumina coating is reported. The film is synthesized by thermally evaporating sequential layers of gold and silver followed by coating an ultra-thin alumina layer using atomic layer deposition. The use of gold as the foundational layer improves the thermal stability of the metal bi-layer film while providing the additional ability to tune the SERS response. Deposition of the thin alumina overlayer on the bi-layer film creates a SERS substrate capable of enduring multiple high-temperature exposures to 400 °C with minimal loss of enhancement capabilities. We demonstrate the multi-use capability of the substrate by measuring the SERS spectrum of rhodamine 6G followed by a thermal treatment at 400 °C to remove the analyte. A representative substrate was used to acquire SERS spectra of rhodamine 6G up to five repeat measurements, thus establishing the reusability of this relatively simple, inexpensive, and stable substrate.

Multiplexed microfluidic surface-enhanced Raman spectroscopy.

Over the past few decades, surface-enhanced Raman spectroscopy (SERS) has garnered respect as an analytical technique with significant chemical and biological applications. SERS is important for the life sciences because it can provide trace level detection, a high level of structural information, and enhanced chemical detection. However, creating and successfully implementing a sensitive, reproducible, and robust SERS active substrate continues to be a challenging task. Herein, we report a novel method for SERS that is based upon using multiplexed microfluidics (MMFs) in a polydimethylsiloxane platform to perform parallel, high throughput, and sensitive detection/identification of single or various analytes under easily manipulated conditions. A facile passive pumping method is used to deliver Ag colloids and analytes into the channels where SERS measurements are done under nondestructive flowing conditions. With this approach, SERS signal reproducibility is found to be better than 7%. Utilizing a very high numerical aperture microscope objective with a confocal-based Raman spectrometer, high sensitivity is achieved. Moreover, the long working distance of this objective coupled with an appreciable channel depth obviates normal alignment issues expected with translational multiplexing. Rapid evaluation of the effects of anion activators and the type of colloid employed on SERS performance are used to demonstrate the efficiency and applicability of the MMF approach. SERS spectra of various pesticides were also obtained. Calibration curves of crystal violet (non-resonant enhanced) and Mitoxantrone (resonant enhanced) were generated, and the major SERS bands of these analytes were observable down to concentrations in the low nM and sub-pM ranges, respectively. While conventional random morphology colloids were used in most of these studies, unique cubic nanoparticles of silver were synthesized with different sizes and studied using visible wavelength optical extinction spectrometry, scanning electron microscopy, and the MMF-SERS approach.