Effect of local prolonged-release incisional doxycycline on surgical site infection prophylaxis in abdominal colorectal surgery: the SHIELD 1 randomized clinical trial.

Introduction: Despite advanced infection control practices including preoperative antibiotic prophylaxis, surgical site infection (SSI) remains a challenge. This study aimed to test whether local administration of a novel prolonged-release doxycycline-polymer-lipid encapsulation matrix (D-PLEX) before wound closure, concomitantly with standard of care (SOC), reduces the incidence of incisional SSI after elective abdominal colorectal surgery.

Materials And Methods: This was a phase 3 randomized, controlled, double-blind, multinational study (SHIELD 1) between June 2020 to June 2022.

Geologic controls on phytoplankton elemental composition.

Planktonic organic matter forms the base of the marine food web, and its nutrient content (C:N:P) governs material and energy fluxes in the ocean. Over Earth history, C:N:P had a crucial role in marine metazoan evolution and global biogeochemical dynamics, but the geologic history of C:N:P is unknown, and it is often regarded constant at the "Redfield" ratio of ∼106:16:1. We calculated C:N:P through Phanerozoic time by including nutrient- and temperature-dependent C:N:P parameterizations in a model of the long-timescale biogeochemical cycles.

Geologic controls on phytoplankton elemental composition.

Planktonic organic matter forms the base of the marine food web, and its nutrient content (C:N:P) governs material and energy fluxes in the ocean. Over Earth history, C:N:P had a crucial role in marine metazoan evolution and global biogeochemical dynamics, but the geologic history of C:N:P is unknown, and it is often regarded constant at the "Redfield" ratio of ∼106:16:1. We calculated C:N:P through Phanerozoic time by including nutrient- and temperature-dependent C:N:P parameterizations in a model of the long-timescale biogeochemical cycles.

Nutrient ratios in marine particulate organic matter are predicted by the population structure of well-adapted phytoplankton.

A common assumption of a constant nitrogen-to-phosphorus ratio (N:P) of 16:1 in marine particulate organic matter (POM) appears to be invalidated by observations of major spatial variations in N:P. Two main explanations have been proposed. The first attributes the N:P variability to changes in the community composition of well-adapted phytoplankton.