Size controlled green synthesis of gold nanoparticles using Coffea arabica seed extract and their catalytic performance in 4-nitrophenol reduction.

Well crystalline gold nanoparticles (AuNPs) of different sizes were fabricated using sundried Coffea arabica seed (CAS) extract at room temperature by controlling the pH of the green extract. The size, shape and crystallinity of the nanoparticles have been studied using electron microscopy and X-ray diffraction. The presence of phenolic groups (revealed through FT-IR studies) from the CAS extract are responsible both for the reduction of Au ions and stabilization of the formed AuNPs. The efficiency of the CAS extract mediated green synthesis technique for the production of AuNPs has been compared to the conventional chemical Turkevich technique, which not only uses a toxic reductant such as NaBH4, but also operates around the boiling point of water. It has been observed that the CAS extract mediated synthesis process produces relatively bigger AuNPs at similar pH values of the reaction mixture in comparison to the AuNPs produced in the Turkevich process. Although the AuNPs synthesized using CAS extract are relatively larger and polydisperse in nature, their catalytic efficiencies for the degradation of an aromatic nitro compound (4-nitrophenol) are found to be comparable to the chemically fabricated AuNPs. Probable mechanisms associated with the formation of AuNPs and their size control in the CAS extract mediated green synthesis process have been discussed.

[Analysis of results, quality indicators, and postsurgical complications in an outpatient dermatological surgery program]. / Análisis de resultados, índices de calidad y complicaciones extrahospitalarias de un programa de cirugía ambulatoria en Dermatología.

OBJECTIVE: To evaluate the results of an outpatient program for major dermatological surgery in patients with a range of skin conditions. METHODS: We undertook a retrospective, observational study of patients who underwent scheduled dermatological surgery as outpatients in a public hospital between 2004 and 2007. The most common procedures were excision of basal cell or squamous cell carcinoma with or without graft reconstruction. The rates of substitution (of inpatient procedures), cancellation, hospital admission, and readmission were analyzed along with service utilization and systemic complications arising within the first 72 hours of surgery. Variables were analyzed as relative frequencies. The occurrence of complications during the study period was analyzed by chi square test. RESULTS: A total of 2789 patients underwent surgery during the study period, and of those, 2757 procedures were performed on an outpatient basis (overall substitution rate, 17.99%). The service utilization was 74.36%. Fourteen patients were admitted to hospital following surgery (2.62%), and of those 12 were admitted immediately (85.71%). Nine patients had serious complications (cardiovascular, neurological, metabolic, or infectious), representing a proportional risk of 1:59. Less serious complications (hypertension, nausea, vomiting, and vasovagal syncope) requiring hospital admission occurred in 25 patients. CONCLUSIONS: Major surgery undertaken on an outpatient basis is an excellent multidisciplinary surgical care model that allows well-selected patients to be treated effectively, safely, and efficiently. A small percentage of postoperative complications of varying severity can still occur despite patients' meeting optimal criteria for success. Fortunately, however, the rate of mortality is practically zero.