Association between use of enhanced recovery after surgery protocols and postoperative complications after gastric surgery for cancer (POWER 4): a nationwide, prospective multicentre study.

INTRODUCTION: The effectiveness of the Enhanced Recovery After Surgery (ERAS) protocols in gastric cancer surgery remains controversial. METHODS: Multicentre prospective cohort study of adult patients undergoing surgery for gastric cancer. Adherence with 22 individual components of ERAS pathways were assessed in all patients, regardless of whether they were treated in a self-designed ERAS centre. Each centre had a three-month recruitment period between October 2019 and September 2020. The primary outcome was moderate-to-severe postoperative complications within 30 days after surgery. Secondary outcomes were overall postoperative complications, adherence to the ERAS pathway, 30 day-mortality and hospital length of stay (LOS). RESULTS: A total of 743 patients in 72 Spanish hospitals were included, 211 of them (28.4 %) from self-declared ERAS centres. A total of 245 patients (33 %) experienced postoperative complications, graded as moderate-to-severe complications in 172 patients (23.1 %). There were no differences in the incidence of moderate-to-severe complications (22.3% vs. 23.5%; OR, 0.92 (95% CI, 0.59 to 1.41); P = 0.068), or overall postoperative complications between the self-declared ERAS and non-ERAS groups (33.6% vs. 32.7%; OR, 1.05 (95 % CI, 0.70 to 1.56); P = 0.825). The overall rate of adherence to the ERAS pathway was 52% [IQR 45 to 60]. There were no differences in postoperative outcomes between higher (Q1, > 60 %) and lower (Q4, ≤ 45 %) ERAS adherence quartiles. CONCLUSIONS: Neither the partial application of perioperative ERAS measures nor treatment in self-designated ERAS centres improved postoperative outcomes in patients undergoing gastric surgery for cancer. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03865810.

Mathematical modeling of drug delivery from one-layer and two-layer torus-shaped devices with external mass transfer resistance.

A mathematical modeling of controlled release of drug from one-layer and two-layer torus-shaped devices with external mass transfer resistance is presented. Analytical solutions based on the pseudo-steady state approximation are derived. The validity of the equations is established in two stages. In the first stage, the validity of the models derived for more complex systems is determined by comparison with profiles predicted by the simplest model, in asymptotic cases. In the second stage, the reliability and usefulness of the models are ascertained by comparison of the simulation results with vaginal rings experimental release data reported in the literature. In order to measures quantitatively the fit of the theoretical models to the experimental data, the pair-wise procedure is used. A good agreement between the prediction of the models and the experimental data is observed. The models are applicable only to torus-shaped systems in where the initial load of drug is higher than its solubility in the polymer.

Mathematical modeling of drug delivery from torus-shaped single-layer devices.

A mathematical modeling of controlled release of drug from torus-shaped single-layer devices is presented. Analytical solutions based on the pseudo-steady state approximation are derived. The reliability and usefulness of the model are ascertained by comparison of the simulation results with matrix-type vaginal ring experimental release data reported in the literature. A good agreement between the model prediction and the experimental data is observed. An analysis of the effect of the variation in torus design parameters on the solute release is also presented. The model is applicable only to torus-shaped single-layer systems wherein the initial load of drug is higher than its solubility in the polymer.

Modeling of dispersed-drug delivery from planar polymeric systems: optimizing analytical solutions.

Analytical solutions for the case of controlled dispersed-drug release from planar non-erodible polymeric matrices, based on Refined Integral Method, are presented. A new adjusting equation is used for the dissolved drug concentration profile in the depletion zone. The set of equations match the available exact solution. In order to illustrate the usefulness of this model, comparisons with experimental profiles reported in the literature are presented. The obtained results show that the model can be employed in a broad range of applicability.

[Population growth rate of the rotifer Brachionus rotundiformis (Rotifera: Brachionidae) in a two-stage chemostat]. / Tasa de crecimiento poblacional del rotífero Brachionus rotundiformis (Rotifera: Brachionidae) en un quimiostato de dos cámaras.

The population growth rate of the rotifer Brachionus rotundiformis (Rotifera: Brachionidae) in two-stage chemostat. The population growth rates of Brachionus rotundiformis were estimated in two-stage chemostat cultures. Chlorella sorokiniana was supplied continuously from a steady state culture growing with constant illumination on limiting nitrate. Rotifer growth in the second stage was limited by the rate of algal supply. The algal supply rate and rotifer population growth rate were determined by the second-stage dilution rate. The maximum population growth rate in the transient state of B. rotundiformis (1.96 day(-1)) was observed at 2.5 x 10(6) cel/ml of the algae whereas in the steady state the maximum population growth rate (1.09 day(-1)) was similar to the point Hopf's bifurcation predicted by Fussmann and was observed at 1 x 10(6) cel/ml of the algae. In the transient state, the rotifer's growth rate increased and the duplication time decreased at higher algal concentrations, until reaching a peak where the population growth rate begins to decrease. In the steady state, the opposite was true. The growth rates observed in this work are among the highest recorded for this rotifer in continuous cultures.

Analisis morfométrico de la laguna Victoria, parque nacional Sierra Nevada Mérida Venezuela / Morphometric analysis of the Victoria lake Sierra Nevada national park Merida Venezuela

La morfometría de la cubeta de los cuerpos de agua continentales afecta sus características físicas, químicas y biológicas. El presente trabajo tuvo como objetivo determinar la morfometría de una laguna de alta montaña tropical, con el fin de relacionarla con los flujos de entrada y salida de agua de la laguna, así como con los tiempos de retención de agua y su estado trófico. El contorno de las isobatas describe una topografía simple. La profundidad relativa de 2,77 por ciento sugiere una tendencia a la estabilidad de la columna de agua. La relación profundidad media: profundidad máxima, refleja que la forma de la cubeta se aproxima a una parábola elíptica. La tasa media de renovación del agua en época de sequía fue de 9,3 horas, mientras que en periodo de lluvias fue de 3,9 horas. El índice S/AV revela que los aportes de fósforo por escorrentía hacia la laguna son importantes. Las curvas hipsográficas área-profundidad de la laguna Victoria sugieren una tendencia a la eutrofía, lo cual es corroborado por las concentraciones de nitrógeno, fósforo y clorofila obtenidos.

The physical, chemical and biological characteristics of lakes and ponds are influence by its morphometry. The objective of the present work was to determine the morphometric parameters of a tropical high mountain lake in order to relate them with the input and the output of water from the lake, the water time retention and the lake trophic state. The depth contours indicates a simple topography. The relative depth 2,77 percent suggests a trend to stability of the water column. The ratio mean depth to maximum depth shows that the basin form is like an elliptic sinusoid. The water mean rate of turnover in the dry season was 9,3 hours, while in the rainy season was 3,9 hours. S/AV index suggests a higher relative importance of runoff inputs of soluble phosphorous. The hypsographic curves of the Victoria Lake suggest a trend to eutrophy which is supported by obtained values of nitrogen, phosphorus and chlorophyll.