5 research outputs found
Strukturna i mehaniÄka svojstva te propusnost biorazgradivih filmova na osnovi zeina
The effect of adding a hydrocolloid on the structural, mechanical and barrier properties of zein-based blend films is evaluated. Zein-oleic acid blend film with added xanthan gum (Z-OA-XG) showed higher water solubility (13.09 %) and opacity (8.49 AU/mm) than zein-oleic acid (Z-OA) fi lm (10.80 % and 5.19 AU/mm, respectively). Furthermore, Z-OA film had greater flexibility with lower Youngâs Modulus (YM=5.02 MPa) and higher elongation at break (η=10.62 %); nonetheless, it was less resistant to tension (tensile strength
Ï=8.5 MPa) than Z-OA-XG film, which showed YM, η and Ï of 6.38 MPa, 6.66 % and 10.485 MPa, respectively. Both films had glossy and homogeneous structure with comparable water vapour and oxygen barrier properties around 4.39·10â11 and 1.82·10â13 g/(Pa·s·m), respectively. Based on that, xanthan gum structure influenced mainly mechanical and light barrier properties of zein-oleic acid blend films.U radu je ispitan utjecaj dodatka hidrokoloida na strukturna i mehaniÄka svojstva te propusnost filmova na osnovi zeina. Film dobiven mijeĆĄanjem zeina i oleinske kiseline uz dodatak ksantanske gume bolje se otapao u vodi (13,09 %), te je bio prozirniji (8,49 AU/mm) od filma bez dodatka ksantanske gume (10,80 % i 5,19 AU/mm). Iako je film dobiven mijeĆĄanjem zeina i oleinske kiseline bio elastiÄniji, te imao niĆŸu vrijednost Youngovog modula elastiÄnosti (YM=5,02 MPa) i veÄu istezljivost (η=10,62 %), imao je slabiju vlaÄnu ÄvrstoÄu (Ï=8,5 MPa) od filma s dodatkom ksantanske gume (YM=638 MPA, η=6,66 % i Ï=10,485 MPa). Oba su filma imala sjajnu povrĆĄinu i homogenu strukturu, te sliÄnu propusnost na vodenu paru od otprilike 4,39âą10-11 g/(Paâąsâąm) i kisika od otprilike 1,82âą10-13 g/(Paâąsâąm). ZakljuÄeno je da struktura ksantanske gume utjeÄe na mehaniÄka svojstva i transparentnost filmova dobivenih mijeĆĄanjem zeina i oleinske kiseline
Biodegradable Zein-Based Blend Films: Structural, Mechanical and Barrier Properties
The effect of adding a hydrocolloid on the structural, mechanical and barrier properties of zein-based blend films is evaluated. Zein-oleic acid blend film with added xanthan gum (Z-OA-XG) showed higher water solubility (13.09 %) and opacity (8.49 AU/mm) than zein-oleic acid (Z-OA) fi lm (10.80 % and 5.19 AU/mm, respectively). Furthermore, Z-OA film had greater flexibility with lower Youngâs Modulus (YM=5.02 MPa) and higher elongation at break (η=10.62 %); nonetheless, it was less resistant to tension (tensile strength
Ï=8.5 MPa) than Z-OA-XG film, which showed YM, η and Ï of 6.38 MPa, 6.66 % and 10.485 MPa, respectively. Both films had glossy and homogeneous structure with comparable water vapour and oxygen barrier properties around 4.39·10â11 and 1.82·10â13 g/(Pa·s·m), respectively. Based on that, xanthan gum structure influenced mainly mechanical and light barrier properties of zein-oleic acid blend films
Influence of ethanol and glycerol concentration over functional and structural properties of zein-oleic acid films
This study was performed in order to determine the effect of the addition of different concentrations of glycerol and ethanol over functional and structural properties of zein-oleic acid films. Films were prepared from zein and oleic acid formulations, containing: 0, 10, 20 and 30% (w/w) of glycerol as plasticizer and 75, 80, 85, 90 and 95% (v/v) of ethanol as zein solvent. Water vapor permeability (WVP) at 4 and 24 C, opacity, water solubility and structural behavior of the film were assessed. The film water barrier properties, WVP and water solubility, were increased when higher ethanol concentration and lower glycerol concentration were used. Furthermore, WVP at 4 C was lower than WVP at 24 C due to the crystalline solid state of oleic acid at lower temperatures. Likewise, opacity, homogeneity and structure of the composite film were improved as ethanol increased and glycerol lowered. © 2013 Elsevier B.V. All rights reserved
Evolution over Time of Ventilatory Management and Outcome of Patients with Neurologic Diseaseâ
OBJECTIVES: To describe the changes in ventilator management over time in patients with neurologic disease at ICU admission and to estimate factors associated with 28-day hospital mortality. DESIGN: Secondary analysis of three prospective, observational, multicenter studies. SETTING: Cohort studies conducted in 2004, 2010, and 2016. PATIENTS: Adult patients who received mechanical ventilation for more than 12 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among the 20,929 patients enrolled, we included 4,152 (20%) mechanically ventilated patients due to different neurologic diseases. Hemorrhagic stroke and brain trauma were the most common pathologies associated with the need for mechanical ventilation. Although volume-cycled ventilation remained the preferred ventilation mode, there was a significant (p < 0.001) increment in the use of pressure support ventilation. The proportion of patients receiving a protective lung ventilation strategy was increased over time: 47% in 2004, 63% in 2010, and 65% in 2016 (p < 0.001), as well as the duration of protective ventilation strategies: 406 days per 1,000 mechanical ventilation days in 2004, 523 days per 1,000 mechanical ventilation days in 2010, and 585 days per 1,000 mechanical ventilation days in 2016 (p < 0.001). There were no differences in the length of stay in the ICU, mortality in the ICU, and mortality in hospital from 2004 to 2016. Independent risk factors for 28-day mortality were age greater than 75 years, Simplified Acute Physiology Score II greater than 50, the occurrence of organ dysfunction within first 48 hours after brain injury, and specific neurologic diseases such as hemorrhagic stroke, ischemic stroke, and brain trauma. CONCLUSIONS: More lung-protective ventilatory strategies have been implemented over years in neurologic patients with no effect on pulmonary complications or on survival. We found several prognostic factors on mortality such as advanced age, the severity of the disease, organ dysfunctions, and the etiology of neurologic disease