scholarly journals Comparative Investigation on the Soil Burial Degradation Behaviour of Polymer Films for Agriculture before and after Photo-Oxidation

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 753 ◽  
Author(s):  
Francesco Paolo La Mantia ◽  
Laura Ascione ◽  
Maria Chiara Mistretta ◽  
Marco Rapisarda ◽  
Paola Rizzarelli

Polymer films based on biodegradable polymers, polyethylene (PE) and modified PE with oxo-degradable additive were prepared by film blowing. Carbon black (1%) was added to all the films. Commercial biodegradable Ecovio® and Mater-Bi® samples were used. Mechanical properties, soil burial degradation and surface wettability were investigated, before and after UV irradiation. Chemical modifications induced by UV and soil degradation, or a synergic effect, were highlighted by Attenuated Total Reflection-Fourier Transform Infra-Red (ATR-FTIR). Photo-oxidized film samples with an elongation at break equal to 50% and 0.5 the initial value were selected for the soil burial degradation test at 30 °C. Weight loss measurements were used to follow biodegradation in soil. Predictably, the degradation in soil was higher for biodegradable polymer-based films than for the PE-based ones. UV irradiation increased surface wettability and encouraged the disintegration in soil of all the samples. In fact, photo-oxidation produced a molar mass reduction and hydrophilic end groups, thus increasing surface erosion and weight loss. This paper not only supplies new criteria to evaluate the performance of biodegradable films in agriculture, before and after lifetime, but also provides a comparative analysis on the soil burial degradation behaviour with traditional ones.

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1489 ◽  
Author(s):  
Rapisarda ◽  
La Mantia ◽  
Ceraulo ◽  
Mistretta ◽  
Giuffrè ◽  
...  

: Irrigation tubes based on biodegradable polymers were prepared via an extrusion-drawing process by Irritec and compared to conventional pipes made of high-density polyethylene (HDPE). A commercial polylactide/poly (butyleneadipate-co-butyleneterephthalate) (PLA/PBAT) blend (Bio-Flex®) and Mater-Bi® were used. The polymers were characterized from rheological and mechanical points of view. Irrigation pipes were subjected to photoaging with continued exposure to UV radiation up to 22 days. The degradability in the soil of irrigation tube samples was studied. The influence of temperature and UV irradiation on soil burial degradation was investigated. A soil burial degradation test was carried out at 30 °C and 50 °C for up to 70 days. The degree of degradation was evaluated from the weight loss percentage. The degradation rate of irrigation tube samples based on Mater-Bi® was higher at 30 °C and was stimulated after 14 days of UV irradiation. Higher temperatures or UV aging encouraged the disintegration in soil of Bio-Flex®-based irrigation tubes. Furthermore, tube samples, before and after UV and soil burial degradation, were analyzed by Attenuated Total Reflection–Fourier Transform Infra-Red (ATR-FTIR) spectroscopy.


2017 ◽  
Vol 1 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Andrea Lončarević ◽  
Marica Ivanković ◽  
Anamarija Rogina

Up till now, chitosan has confirmed its versatile application in skin, cartilage and bone tissue engineering, as well as in drug delivery applications. This study is focused on enzymatic degradation of porous chitosan structures usually designed for mentioned purposes. In vitro degradation was monitored during four weeks of incubation at physiological temperature and in two different media, phosphate buffer saline solution and water. The scaffolds were characterised before and after enzymatic degradation using scanning electron microscopy and infrared spectroscopy with Fourier transformations (FTIR). According to the gravimetric analysis, higher weight loss of chitosan scaffolds was observed in buffered medium with respect to the water. The results implied that the total weight loss obtained in buffer involves physical dissolution of chitosan and lysozyme cleavage of glycoside bond. Importantly, FTIR identification of chitosan scaffolds after enzymatic degradation indicated the absence of lysozyme activity in water, indicating that weight loss is a result of the chitosan dissolution. This finding greatly impacts design of degradation experiments and characterisation of degradation behaviour of chitosan-based materials utilised as implants or drug delivery systems.


1990 ◽  
Vol 156 (6) ◽  
pp. 875-877 ◽  
Author(s):  
I. M. Anderson ◽  
S. E. Gartside ◽  
P. J. Cowen

Overnight plasma melatonin level was measured in ten healthy women before and after a 4300 kJ (1000 kcaI) diet in which they lost an average 3.1 kg. This weight loss did not significantly alter melatonin levels.


Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1113
Author(s):  
Takeshi Kikutani ◽  
Yoko Ichikawa ◽  
Eri Kitazume ◽  
Arato Mizukoshi ◽  
Takashi Tohara ◽  
...  

Background: In older people with psychoneurological diseases, COVID-19 infection may be associated with a risk of developing or exacerbating dysphagia. The aim of the present study was to examine the relationship between eating/swallowing function and COVID-19 infection. Methods: Subjects were 44 inpatients with confirmed COVID-19 infection being treated for schizophrenia in a psychiatric ward. Eating function was assessed using the Food Intake Level Scale (FILS) before and after infection. We also evaluated age, comorbidities, COVID-19 hospital stay, obesity index, weight loss rate, and chlorpromazine equivalent. Results: Subjects had a mean age of 68.86 years. Pre-infection, 20 subjects had a FILS score of 7–9 (presence of eating/swallowing disorder) and 24 subjects had a score of 10 (normal). Eating function after infection resolution showed decreasing FILS score compared to that before infection in 14 subjects (74.14 years). Six subjects (79.3 years) transitioned from oral feeding to parenteral feeding. A ≥ 10% weight loss during infection treatment was significantly associated with decreased eating function and a transition to parenteral feeding. Chlorpromazine equivalents, comorbidities, and number of days of hospitalization showed no associations with decreased eating function. Conclusions: Preventing malnutrition during treatment for COVID-19 infection is important for improving post-infection life prognosis and maintaining quality of life (QOL).


Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 726
Author(s):  
Ronald Biemann ◽  
Enrico Buß ◽  
Dirk Benndorf ◽  
Theresa Lehmann ◽  
Kay Schallert ◽  
...  

Gut microbiota-mediated inflammation promotes obesity-associated low-grade inflammation, which represents a hallmark of metabolic syndrome. To investigate if lifestyle-induced weight loss (WL) may modulate the gut microbiome composition and its interaction with the host on a functional level, we analyzed the fecal metaproteome of 33 individuals with metabolic syndrome in a longitudinal study before and after lifestyle-induced WL in a well-defined cohort. The 6-month WL intervention resulted in reduced BMI (−13.7%), improved insulin sensitivity (HOMA-IR, −46.1%), and reduced levels of circulating hsCRP (−39.9%), indicating metabolic syndrome reversal. The metaprotein spectra revealed a decrease of human proteins associated with gut inflammation. Taxonomic analysis revealed only minor changes in the bacterial composition with an increase of the families Desulfovibrionaceae, Leptospiraceae, Syntrophomonadaceae, Thermotogaceae and Verrucomicrobiaceae. Yet we detected an increased abundance of microbial metaprotein spectra that suggest an enhanced hydrolysis of complex carbohydrates. Hence, lifestyle-induced WL was associated with reduced gut inflammation and functional changes of human and microbial enzymes for carbohydrate hydrolysis while the taxonomic composition of the gut microbiome remained almost stable. The metaproteomics workflow has proven to be a suitable method for monitoring inflammatory changes in the fecal metaproteome.


2012 ◽  
Vol 43 (4) ◽  
pp. 271-277 ◽  
Author(s):  
A. Tvarijonaviciute ◽  
A.M. Gutiérrez ◽  
I. Miller ◽  
E. Razzazi-Fazeli ◽  
F. Tecles ◽  
...  

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Yang Niu ◽  
Xue-lin Zhao ◽  
Hui-juan Ruan ◽  
Xiao-meng Mao ◽  
Qing-ya Tang

Abstract Background Current adult studies suggest that uric acid (UA) is associated with body fat, but the relationship in obese children is unclear. Thus, we aim to evaluate the association between uric acid and body composition of obese children. Methods A total of 79 obese children were included in this study, and 52 children (34 boys and 18 girls) underwent a 6-week weight loss camp, including 34 boys and 18 girls. Six-week weight-loss interventions were performed on all participants through aerobic exercise and appropriate dietary control. Laboratory tests and body composition were collected before and after the intervention. Results Before the intervention, correlation analysis demonstrated that uric acid was positively correlated with height, weight, body mass index (BMI), waist circumference, hip circumference, fat mass (FM), and free fat mass (FFM) with adjusting for age and gender (P < 0.05). After 6 weeks of intervention, the participants gained 3.12 ± 0.85 cm in height, body fat percentage decreased by 7.23 ± 1.97%, and lost 10.30 ± 2.83 kg in weight. Univariate and multivariate analysis indicated that uric acid at baseline was associated with FM reduction during weight loss (P < 0.05). Conclusions This study is the first report that uric acid is associated with BMI and FM, and may play an important role in the reduction of FM during weight loss in obese children and adolescents. The interaction between UA and adiposity factors and its underlying mechanisms need to be further explored. Trial registration This study was registered in Clinical Trials.gov (NCT03490448) and approved by the Ethics Committee of Xinhua Hospital, Shanghai Jiao Tong University School of Medicine.


2012 ◽  
Vol 81 (3) ◽  
pp. 263-267 ◽  
Author(s):  
Metin Guldas ◽  
Canan Hecer

Effects of seven different solutions prepared from various additives (carrageenan, konjac flour, phosphate, yeast extract, xanthan gum and maltodextrin) were used to test for the first time in the marination of experimental seafood. The additives were added into the marination solutions and the samples were analyzed before and after marination. Statistically, the experimental solutions did not cause significant changes in pH, acidity and salt content of the samples (P < 0.05). The highest weight gains were obtained from the solution which contained 0.1% of konjac flour (E425 I) as 4.01, 5.21, 4.61 and 4.88 % in the mussels, big squids, diced squids and small squids, respectively. However, this solution was not preferred by the panellists because of its sticky texture. Inversely to red meat products, the solution containing phosphate caused weight loss during marination. The results indicate that the solution containing 0.2% carrageenan LM (low methoxyl) was the best solution in the marination process. Dipping into this solution caused weight gains of 4.69, 2.98, 4.04 and 2.78% in the big squids, the mussels, the small squids and the diced squids, respectively (P < 0.01). The organoleptic properties (mouth feel, flavour and softness) of mussels and squids were also improved by carrageenan LM addition.


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