An amperometric sensor for lactate quantification is presented. The developed biosensor requires only 0.2 U of lactate oxidase, which is immobilized in a mucin/albumin hydrogel matrix. By protecting the platinum surface with a Nafion membrane, typical interference related to negatively charged species such as ascorbic acid has been minimized to practically undetectable levels. Electrochemical properties associated with the Nafion membrane are assessed as a function of Nafion concentration. In a phosphate buffer solution of pH 7.0, linear dependence of the catalytic current upon lactate bulk concentration was obtained between 2 and approximately 1000 microM. A detection limit of 0.8 microM can be calculated considering 3 times the standard deviation of the blank signal divided by the sensitivity of the sensor. The lactate biosensor presents remarkable operational stability and sensitivity (0.537 +/- 0.007) mA.M(-1), where the error is the standard deviation of the slope calculated from the linear regression of the calibration curve of a fresh biosensor. In this regard, the sensor keeps practically the same sensitivity for 5 months, while the linear range decreases until an upper value of 0.8 mM is reached. Assays performed with whole blood samples spiked with 100 microM lactate gave (89 +/- 6)% of recovery.

ObjectiveTo determine the effectiveness of a quality management program in reducing the incidence and severity of pressure ulcers in critical care patients.MethodsThis was a quasi-experimental, before-and-after study that was conducted in a medical-surgical intensive care unit. Consecutive patients who had received mechanical ventilation for ≥ 96 hours were included. A "Process Improvement" team designed a multifaceted interventional process that consisted of an educational session, a pressure ulcer checklist, a smartphone application for lesion monitoring and decision-making, and a "family prevention bundle".ResultsFifty-five patients were included in Pre-I group, and 69 were included in the Post-I group, and the incidence of pressure ulcers in these groups was 41 (75%) and 37 (54%), respectively. The median time for pressure ulcers to develop was 4.5 [4 - 5] days in the Pre-I group and 9 [6 - 20] days in the Post-I group after admission for each period. The incidence of advanced-grade pressure ulcers was 27 (49%) in the Pre-I group and 7 (10%) in the Post-I group, and finally, the presence of pressure ulcers at discharge was 38 (69%) and 18 (26%), respectively (p < 0.05 for all comparisons). Family participation totaled 9% in the Pre-I group and increased to 57% in the Post-I group (p < 0.05). A logistic regression model was used to analyze the predictors of advanced-grade pressure ulcers. The duration of mechanical ventilation and the presence of organ failure were positively associated with the development of pressure ulcers, while the multifaceted intervention program acted as a protective factor.ConclusionA quality program based on both a smartphone application and family participation can reduce the incidence and severity of pressure ulcers in patients on prolonged acute mechanical ventilation.

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Supramolecular materials based on noncovalent bonds have attracted considerable attention in several fields due to their special characteristics such as self-healing, shape memory, and stimuli-responsive properties among others. [1][2][3][4][5][6][7][8][9][10] Indeed, multiple hydrogen bonding are ideal reversible noncovalent interactions for preparing supramolecular networks combining high strength and excellent reversibility. [11][12][13][14][15][16][17][18][19][20][21] Supramolecular Thermoresponsive Hydrogels Supramolecular hydrogels have promising applications in a wide variety of fields including 3D bioprinting, sensors and actuators, biomedicine, and controlled drug delivery. This communication reports the facile reversible thermotriggered formation of novel pH-responsive supramolecular hydrogels based on poly(vinyl alcohol) (PVA) bonded via dynamic H-bridge with small phenolic biomolecules. PVA and phenolic compounds form a clear solution when they are physically mixed in water at high temperature, but a fast gelation is produced at room temperature through multiple strong H-bonding interactions. The structure and type of functional groups of different phenolic molecules allow preparing hydrogels with tailor-made viscoelastic properties, controlled low phase transition temperature, and pH-dependent swelling behavior. This combination makes these supramolecular networks very interesting candidates to be used in 3D bioprinting and topical drug delivery of thermolabile biomolecules.

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