30 research outputs found
Study on hydrophobic modification of basil seed gum-based (BSG) films by octenyl succinate anhydride (OSA)
The main objective of this study was to evaluate the changes in the characteristics of basil (Ocimum bacilicum L.) seed gum (BSG) films after modification with octenyl succinate anhydride (OSA) at different OSA:BSG weight ratios (WRs) of 0, 0.01 and 0.03. HPLC analysis revealed that the amount of added OS groups was 0%, 0.28%, and 1.01%, respectively. The introduction of OS groups along the BSG backbone was also confirmed by FT-IR and NMR analysis. XRD results revealed no significant change of physical state after modification. The contact angle (i.e., hydrophobicity) of modified BSG films was higher than that of control film. A decrease in the film solubility in water (29%) and water vapor permeability (50%), but an increase in density (14.28%) and opacity (21.37%) was observed after modification at the WR of 0.03. Also, the results showed that modification with OSA had no significant influence on the film thickness, moisture content and color properties. BSG modification with OSA at the WR of 0.03 significantly increased the flexibility and ultimate strength of respective films. The results of this study showed that OSA-modified BSG is a good candidate for developing edible films and coating with relatively high resistance to water
Comparison of hybrid regression and multivariate regression in the regional flood frequency analysis: A case study in Khorasan Razavi province
Background: Magnitude, rate and frequency of the stochastic and unexpected events are of great
significance and importance in hydrology. Nowadays, for economic planning of the projects, the use
of analytical methods of unexpected events in hydrology is unavoidable. The aim of this study was to
compare hybrid regression and multivariate regression to estimate flood peak discharge in the province
of Khorasan Razavi and in the selected water measured stations.
Methods: For this purpose, 19 hydrometric stations were selected and analyzed. In the first step, the
rate of peak discharge was estimated with different return periods and by selecting the best regional
distribution (lognormal distribution type ΠΙ). In the next step, independent and important variables
including area, mean annual rainfall, the average height of the watershed and its slope were determined
using functional analysis and using SPSS software version 22. Then, two hydrologically homogeneous
regions were determined by homogeneity test using cluster analysis, and accordingly, two models were
presented for the whole area and also for homogeneous areas. To compare and evaluate the accuracy
and efficiency of the estimated models, the rates of discharges were estimated and compared with
observational rates using three control watersheds. To compare models, it was used from the average
absolute values of the relative error index.
Results: It was revealed that the hybrid method was more accurate than the multivariate regression
method in the return period of 50 years and provides better results of flood discharges for the area.
Homogenous areas had a higher coefficient of determination (R2) and lower relative standard error
(RSE) compared to the whole area. It was also revealed that with increase of return period, the rates of
R2 decreased but the rates of relative standard error increased.
Conclusion: The accuracy of multivariate regression and hybrid methods was the same in the 25-year
return period. In the present study, the importance and necessity of homogenous areas compared with
the model of the whole area are completely evident.
Keywords: Floods, Regression analysis, Khorasan Razavi province, Statistical distributions, Hybrid
regressio
Effects of Topical 1% Sodium Hyaluronate and Hydroxypropyl Methylcellulose in Treatment of Corneal Epithelial Defects
We aimed to compare the therapeutic effects of topical 1% sodium hyaluronate (Healon) or hydroxypropyl methylcellulose (HPMC) for the treatment of alkali-induced epithelial corneal defects. An alkali burn was produced in 30 corneas of 30 New Zealand White rabbits, using a 7.5-mm-diameter trephine. The rabbits were randomly divided into three groups. Four times a day, one group was treated with 1% sodium hyaluronate, one with HPMC, and one (the control group) with physiologic saline. During the treatment period, the size of the epithelial defect was observed every day, up to day 17, using a slit-lamp biomicroscope (with fluorescein). Sodium hyaluronate significantly accelerated the wound healing process compared with saline and increased the healing rate to an even greater extent compared with HPMC. Sodium hyaluronate, but not HPMC, is an effective wound-healing adjuvant for alkali-induced corneal epithelial defects.Â
Effect of Intermediate-Dose vs Standard-Dose Prophylactic Anticoagulation on Thrombotic Events, Extracorporeal Membrane Oxygenation Treatment, or Mortality among Patients with COVID-19 Admitted to the Intensive Care Unit: The INSPIRATION Randomized Clinical Trial
Importance: Thrombotic events are commonly reported in critically ill patients with COVID-19. Limited data exist to guide the intensity of antithrombotic prophylaxis. Objective: To evaluate the effects of intermediate-dose vs standard-dose prophylactic anticoagulation among patients with COVID-19 admitted to the intensive care unit (ICU). Design, Setting, and Participants: Multicenter randomized trial with a 2 � 2 factorial design performed in 10 academic centers in Iran comparing intermediate-dose vs standard-dose prophylactic anticoagulation (first hypothesis) and statin therapy vs matching placebo (second hypothesis; not reported in this article) among adult patients admitted to the ICU with COVID-19. Patients were recruited between July 29, 2020, and November 19, 2020. The final follow-up date for the 30-day primary outcome was December 19, 2020. Interventions: Intermediate-dose (enoxaparin, 1 mg/kg daily) (n = 276) vs standard prophylactic anticoagulation (enoxaparin, 40 mg daily) (n = 286), with modification according to body weight and creatinine clearance. The assigned treatments were planned to be continued until completion of 30-day follow-up. Main Outcomes and Measures: The primary efficacy outcome was a composite of venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days, assessed in randomized patients who met the eligibility criteria and received at least 1 dose of the assigned treatment. Prespecified safety outcomes included major bleeding according to the Bleeding Academic Research Consortium (type 3 or 5 definition), powered for noninferiority (a noninferiority margin of 1.8 based on odds ratio), and severe thrombocytopenia (platelet count <20 �103/µL). All outcomes were blindly adjudicated. Results: Among 600 randomized patients, 562 (93.7) were included in the primary analysis (median interquartile range age, 62 50-71 years; 237 42.2% women). The primary efficacy outcome occurred in 126 patients (45.7%) in the intermediate-dose group and 126 patients (44.1%) in the standard-dose prophylaxis group (absolute risk difference, 1.5% 95% CI,-6.6% to 9.8%; odds ratio, 1.06 95% CI, 0.76-1.48; P =.70). Major bleeding occurred in 7 patients (2.5%) in the intermediate-dose group and 4 patients (1.4%) in the standard-dose prophylaxis group (risk difference, 1.1% 1-sided 97.5% CI,-� to 3.4%; odds ratio, 1.83 1-sided 97.5% CI, 0.00-5.93), not meeting the noninferiority criteria (P for noninferiority >.99). Severe thrombocytopenia occurred only in patients assigned to the intermediate-dose group (6 vs 0 patients; risk difference, 2.2% 95% CI, 0.4%-3.8%; P =.01). Conclusions and Relevance: Among patients admitted to the ICU with COVID-19, intermediate-dose prophylactic anticoagulation, compared with standard-dose prophylactic anticoagulation, did not result in a significant difference in the primary outcome of a composite of adjudicated venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days. These results do not support the routine empirical use of intermediate-dose prophylactic anticoagulation in unselected patients admitted to the ICU with COVID-19. Trial Registration: ClinicalTrials.gov Identifier: NCT04486508. © 2021 American Medical Association. All rights reserved
Atmospheric Pressure Cold Plasma Modification of Basil Seed Gum for Fabrication of Edible Film Incorporated with Nanophytosomes of Vitamin D<sub>3</sub> and Tannic Acid
The purpose of this work was to first investigate the impact of cold plasma (CP) treatment, performed at various times (0–30 min), on the characteristics of basil seed gum (BSG), as well as the fabrication of functional edible films with the modified BSG. FT-IR spectra of CP-treated BSG revealed change at 1596 and 1718 cm−1, indicating the formation of carbonyl groups. Both untreated and CP-modified BSG dispersions showed shear-thinning behavior with a higher apparent viscosity for the CP-modified dispersions at studied temperatures. Untreated BSG dispersion and the one treated by CP for 10 min revealed time-independent behavior, while those treated for 20 and 30 min showed a rheopectic behavior. CP-modified BSG dispersion had higher G′, G″, and complex viscosity than untreated BSG. Higher contact angle for the CP-modified BSG suggested enhanced hydrophobic nature, while the surface tension was lower compared to the untreated BSG. SEM micrographs revealed an increase in the surface roughness of treated samples. Moreover, modified BSG was successfully used for the preparation of edible film incorporating tannic acid and vitamin D3-loaded nanophytosomes with high stability during storage compared to the free form addition. The stability of encapsulated forms of vitamin D3 and tannic acid was 39.77% and 38.91%, more than that of free forms, respectively. In conclusion, CP is an appropriate technique for modifying the properties of BSG and fabrication of functional edible films
Auto‐catalytic production of eugenyl acetate and eugenyl butyrate using microwave radiation: a kinetic and mechanism‐related approach
International audienceBACKGROUND : Applications of chemical and enzymatic methods of esterification have been limited by low selectivity of chemical catalysts and low productivity and high cost of enzymes. The objective of this study was to produce eugenol esters with high productivity and selectivity using a microwave technique without adding any catalyst or solvent. Specific focus was given to reaction temperature and molar ratio to establish the kinetics and mechanism of eugenol auto‐catalytic acylation using microwave radiation.RESULTS : Reaction conversion was observed to increase in response to higher temperatures. The optimum molar ratio of eugenyl/acetic anhydride was 1:6, while the optimum molar ratio of eugenyl/butyric anhydride was 1:4.5. A high degree of selectivity (of over 97%) occurred under all conditions of the reaction. Based on modelling studies, it can be concluded that the intended reaction follows second‐order kinetics for both eugenyl acetate and eugenyl butyrate. Microwave heating at 70 °C led to an increase of rate constant by 3.71‐ and 3.83‐fold for eugenyl acetate and eugenyl butyrate, respectively, as compared to the conventional method. This was associated with a decrease in the activation energy (4.38% for eugenyl acetate and 3.11% for eugenyl butyrate) and an increase in the frequency factor (42.31% for eugenyl acetate and 49.84% for eugenyl butyrate) and entropy (4.71% for eugenyl acetate and 5.22% for eugenyl butyrate) as a result of using microwave radiation.CONCLUSIONS : The microwave technique can be considered as a green, low‐cost and quick process for auto‐catalytic production of eugenol esters. © 2020 Society of Chemical Industry (SCI
Development and characterization of medium and high internal phase novel multiple Pickering emulsions stabilized by hordein nanoparticles
Medium and high internal phase W1/O/W2 multiple Pickering emulsions (MPEs) were fabricated by physically-modified hordein nanoparticles. A triphasic system was developed at dispersed phase volume fraction (Φ) of 0.5 with an overrun value of ∼40%. No overrun was detected in high internal phase MPEs (Φ 0.8). Optical and confocal laser scanning microscopy confirmed the formation of MPEs. Monomodal droplet size distribution with a mean diameter of 32.90 and 21.48 μm was observed for MPEs at Φ 0.5 and Φ 0.8, respectively. Static multiple light scattering confirmed that creaming was the main mechanism behind the instability of MPEs. Both MPEs revealed pseudo-plastic behavior and predominant storage modulus (G′) over the applied frequency range. The encapsulation efficiency of vitamin B12 in MPEs was 98.3% and remained relatively constant during 28 d. These results suggested the excellent potential of hordein nanoparticles as appropriate candidate for designing multi-structural colloidal systems using plant proteins
Promising application of probiotic microorganisms as Pickering emulsions stabilizers
Abstract The purpose of this work was to study the ability of nineteen food-grade microorganisms as Pickering emulsion (PE) stabilizers. Medium-chain triacylglycerol (MCT) oil-in-water (50:50) PEs were fabricated by 10 wt% or 15 wt% of thermally-inactivated yeast, cocci, Bacillus spp. and lactobacilli cells. The characteristics of microorganisms related to “Pickering stabilization” including morphology, surface charge, interfacial tension, and “contact angle” were firstly studied. After that, the cells-stabilized PEs were characterized from both kinetic and thermodynamic viewpoints, microstructure and rheological properties. The interfacial tension and “contact angle” values of various microorganisms ranged from 16.33 to 38.31 mN/m, and from 15° to 106°, respectively. The mean droplet size of PEs ranged from 11.51 to 57.69 µm. Generally, the physical stability of cell-stabilized PEs followed this order: lactobacilli > Bacillus spp. > cocci > yeast. These variations were attributed to the morphology and cell wall composition. Increasing the microorganism concentration significantly increased the physical stability of PEs from a maximum of 12 days at 10 wt% to 35 days at 15 wt% as a result of better interface coverage. Shear-thinning and dominant elastic behaviors were observed in PEs. Physical stability was affected by the free energy of detachment. Therefore, food-grade microorganisms are suggested for stabilizing PEs
Alginate/whey protein isolate-based emulgel as an alternative margarine replacer in processed cheese: Impact on rheological, mechanical, nutritional, and sensory characteristics
ABSTRACT: The effects of partial or full replacement of margarine by alginate/whey protein isolate-based olive oil emulgel on nutritional, physicochemical, mechanical, and rheological properties of processed cheese (PC) were investigated in this work. All formulated samples had the same amount of total fat, DM, and pH. According to the results of the fatty acids profile, the PC sample in which the margarine was fully replaced by the emulgel (EPC100) had the highest (49.84%) oleic acid content and showed a reduction of 23.7% in SFA compared with the control sample (EPC0; formulated just with margarine). In addition, EPC0 had the highest hardness among various cheese samples, which was also confirmed by its compact microstructure. Dynamic oscillatory measurements revealed that EPC100 had the highest crossover strain (or resistance to deformation). The high rigidity of this sample was related to the 3-dimensional structure of emulgel. According to the creep test results, EPC100 showed the lowest relative recovery (flowability). A high temperature dependency of viscoelastic moduli was observed in EPC0 at 42°C. No significant differences were observed between the color attributes and sensory properties of the various cheese samples. Alginate/whey protein isolate-based olive oil emulgel can be considered as a healthy margarine replacer in PC