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Environmental Research May 2023Pyrolysis oil from oil palm biomass can be a sustainable alternative to fossil fuels and the precursor for synthesizing petrochemical products due to its carbon-neutral...
Pyrolysis oil from oil palm biomass can be a sustainable alternative to fossil fuels and the precursor for synthesizing petrochemical products due to its carbon-neutral properties and low sulfur and nitrogen content. This work investigated the effect of applying mesoporous acidic catalysts, Ni-Mo/TiO and Ni/AlO in a catalytic co-pyrolysis of oil palm trunk (OPT) and polypropylene (PP) from 500 to 700 °C. The obtained oil yields varied between 12.67 and 19.50 wt.% and 12.33-17.17 wt.% for Ni-Mo/TiO and Ni/AlO, respectively. The hydrocarbon content in oil significantly increased up to 54.07-58.18% and 37.28-68.77% after adding Ni-Mo/TiO and Ni/AlO, respectively. The phenolic compounds content was substantially reduced to 8.46-20.16% for Ni-Mo/TiO and 2.93-14.56% for Ni/AlO. Minor reduction in oxygenated compounds was noticed from catalytic co-pyrolysis, though the parametric effects of temperature and catalyst type remain unclear. The enhanced deoxygenation and cracking of phenolic and oxygenated compounds and the PP decomposition resulted in increased hydrocarbon production in oil during catalytic co-pyrolysis. Catalyst addition also promoted the isomerization and oligomerization reactions, enhancing the formation of cyclic relative to aliphatic hydrocarbon.
Topics: Polypropylenes; Pyrolysis; Titanium; Hydrocarbons; Catalysis; Biomass; Biofuels; Hot Temperature
PubMed: 36841526
DOI: 10.1016/j.envres.2023.115550 -
Microbiological Research Dec 2023The urgent need for better disposal and recycling of plastics has motivated a search for microbes with the ability to degrade synthetic polymers. While microbes capable...
The urgent need for better disposal and recycling of plastics has motivated a search for microbes with the ability to degrade synthetic polymers. While microbes capable of metabolizing polyurethane and polyethylene terephthalate have been discovered and even leveraged in enzymatic recycling approaches, microbial degradation of additive-free polypropylene (PP) remains elusive. Here we report the isolation and characterization of two fungal strains with the potential to degrade pure PP. Twenty-seven fungal strains, many isolated from hydrocarbon contaminated sites, were screened for degradation of commercially used textile plastic. Of the candidate strains, two identified as Coniochaeta hoffmannii and Pleurostoma richardsiae were found to colonize the plastic fibers using scanning electron microscopy (SEM). Further experiments probing degradation of pure PP films were performed using C. hoffmannii and P. richardsiae and analyzed using SEM, Raman spectroscopy and Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR). The results showed that the selected fungi were active against pure PP, with distinct differences in the bonds targeted and the degree to which each was altered. Whole genome and transcriptome sequencing was conducted for both strains and the abundance of carbohydrate active enzymes, GC content, and codon usage bias were analyzed in predicted proteomes for each. Enzymatic assays were conducted to assess each strain's ability to degrade naturally occurring compounds as well as synthetic polymers. These investigations revealed potential adaptations to hydrocarbon-rich environments and provide a foundation for further investigation of PP degrading activity in C. hoffmannii and P. richardsiae.
Topics: Plastics; Polypropylenes; Ascomycota; Fungi; Biodegradation, Environmental
PubMed: 37793281
DOI: 10.1016/j.micres.2023.127507 -
Scientific Reports Aug 2017Marine debris is widely recognized as a global environmental problem. One of its main components, microplastics, has been found in several sea salt samples from...
Marine debris is widely recognized as a global environmental problem. One of its main components, microplastics, has been found in several sea salt samples from different countries, indicating that sea products are irremediably contaminated by microplastics. Previous studies show very confusing results, reporting amounts of microparticles (MPs) in salt ranging from zero to 680 MPs/kg, with no mention of the possible causes of such differences. Several errors in the experimental procedures used were found and are reported in the present work. Likewise, 21 different samples of commercial table salt from Spain have been analyzed for MPs content and nature. The samples comprise sea salts and well salts, before and after packing. The microplastic content found was of 50-280 MPs/kg salt, being polyethylene-terephthalate (PET) the most frequently found polymer, followed by polypropylene (PP) and polyethylene (PE), with no significant differences among all the samples. The results indicate that even though the micro-particles might originate from multiple sources, there is a background presence of microplastics in the environment.
Topics: Environmental Monitoring; Food Contamination; Phthalic Acids; Plastics; Polyethylene; Polyethylene Terephthalates; Polypropylenes; Sodium Chloride, Dietary; Spain; Water Pollutants, Chemical
PubMed: 28819264
DOI: 10.1038/s41598-017-09128-x -
Acta Cirurgica Brasileira Jun 2015To compare the inflammatory response of three different meshes on abdominal hernia repair in an experimental model of incisional hernia. (Comparative Study)
Comparative Study
PURPOSE
To compare the inflammatory response of three different meshes on abdominal hernia repair in an experimental model of incisional hernia.
METHODS
Median fascial incision and skin synthesis was performed on 30 Wistar rats. After 21 days, abdominal hernia developed was corrected as follows: 1) No mesh; 2) Polypropylene mesh; and, 3) Ultrapro(r) mesh. After 21 days, the mesh and surrounding tissue were submitted to macroscopic (presence of adhesions, mesh retraction), microscopic analysis to identify and quantify the inflammatory and fibrotic response using a score based on a predefined scale of 0-3 degrees, evaluating infiltration of macrophages, giant cells, neutrophils and lymphocytes.
RESULTS
No significant difference was seen among groups in adherences, fibrosis, giant cells, macrophages, neutrophils or lymphocytes (p>0.05). Mesh shrinkage was observed in all groups, but also no difference was observed between polypropylene and Ultrapro mesh (7.0±9.9 vs. 7.4±10.1, respectively, p=0.967). Post-operatory complications included fistula, abscess, dehiscence, serohematic collection and reherniation, but with no difference among groups (p=0.363).
CONCLUSION
There is no difference between polypropylene (high-density) and Ultrapro(r) (low-density) meshes at 21 days after surgery in extraperitoneal use in rats, comparing inflammatory response, mesh shortening, adhesions or complications.
Topics: Animals; Dioxanes; Hernia, Ventral; Herniorrhaphy; Male; Materials Testing; Polyesters; Polypropylenes; Rats, Wistar; Reproducibility of Results; Surgical Mesh; Time Factors; Tissue Adhesions; Treatment Outcome
PubMed: 26108024
DOI: 10.1590/S0102-865020150060000001 -
Microbiological Research Feb 2023Microorganisms degrade microplastics, but their potential is still not fully exploited, e.g., due to inadequate selection of microorganisms. We developed an effective...
Microorganisms degrade microplastics, but their potential is still not fully exploited, e.g., due to inadequate selection of microorganisms. We developed an effective selection method of microorganisms capable of polyethylene (PE) and polypropylene (PP) degradation and assessed the scale of polymer degradation by microbial populations. We isolated seven bacterial strains (three Priestia megaterium strains, Klebsiella pneumoniae, Pseudomonas fluorescens, Enterobacter ludwigii, Chryseobacterium sp.) and seven fungal strains (four Fusarium spp., two Lecanicillium spp. and Trichoderma sp.) with PE degradation potential, as well as seven bacterial strains (five Serratia marcescens and two Enterobacter spp.) and six fungal strains (four Aspergillus spp., Fusarium oxysporum and Penicillium granulatum) with PP degradation ability. Scanning electron microscopy (SEM) analysis confirmed the presence of a biofilm and revealed surface changes in both PE and PP pellets, but the greatest changes (microcracks and corrugations) were observed for PP incubated with bacteria. Fourier transform infrared (FTIR) spectroscopy confirmed the structural changes on the studied polymer surfaces. In conclusion, the isolation of plastic-degrading bacteria and fungi from waste landfills represents an effective strategy for the collection of microorganisms with high potential for PE and PP degradation. The bacteria and fungi revealed better potential for PP degradation and PE degradation, respectively.
Topics: Polyethylene; Polypropylenes; Plastics; Biodegradation, Environmental; Fungi
PubMed: 36423546
DOI: 10.1016/j.micres.2022.127251 -
Acta Cirurgica Brasileira 2021To compare tissue inflammatory response, foreign body reaction, fibroplasia, and proportion of type I/III collagen between closure of abdominal wall aponeurosis using...
Analysis of tissue inflammatory response, fibroplasia, and foreign body reaction between the polyglactin suture of abdominal aponeurosis in rats and the intraperitoneal implant of polypropylene, polypropylene/polyglecaprone and polyester/porcine collagen meshes.
PURPOSE
To compare tissue inflammatory response, foreign body reaction, fibroplasia, and proportion of type I/III collagen between closure of abdominal wall aponeurosis using polyglactin suture and intraperitoneal implant of polypropylene, polypropylene/polyglecaprone, and polyester/porcine collagen meshes to repair defects in the abdominal wall of rats.
METHODS
Forty Wistar rats were placed in four groups, ten animals each, for the intraperitoneal implant of polypropylene, polypropylene/polyglecaprone, and polyester/porcine collagen meshes or suture with polyglactin (sham) after creation of defect in the abdominal wall. Twenty-one days later, histological analysis was performed after staining with hematoxylin-eosin and picrosirius red.
RESULTS
The groups with meshes had a higher inflammation score (p < 0.05) and higher number of gigantocytes (p < 0.05) than the sham group, which had a better fibroplasia with a higher proportion of type I/III collagen than the tissue separating meshes (p < 0.05). There were no statistically significant differences between the three groups with meshes.
CONCLUSIONS
The intraperitoneal implant of polypropylene/polyglecaprone and polyester/porcine collagen meshes determined a more intense tissue inflammatory response with exuberant foreign body reaction, immature fibroplasia and low tissue proportion of type I/III collagen compared to suture with polyglactin of abdominal aponeurosis. However, there were no significant differences in relation to the polypropylene mesh group.
Topics: Abdominal Wall; Animals; Aponeurosis; Collagen; Foreign-Body Reaction; Materials Testing; Polyglactin 910; Polypropylenes; Rats; Rats, Wistar; Surgical Mesh; Sutures; Swine
PubMed: 34495141
DOI: 10.1590/ACB360706 -
European Journal of Hospital Pharmacy :... Mar 2023Clonidine is an alpha-2 adrenoreceptor agonist and is frequently combined with opioids (ie, morphine hydrochloride (HCl)) for the management of chronic pain. In...
OBJECTIVES
Clonidine is an alpha-2 adrenoreceptor agonist and is frequently combined with opioids (ie, morphine hydrochloride (HCl)) for the management of chronic pain. In palliative care, the administration of clonidine and morphine HCl is recommended in case of tolerance effect. This study aimed to evaluate the physical and chemical stability of this admixture at high and low concentrations in 14 and 48 mL polypropylene syringes.
METHODS
The stability of a low concentration admixture of clonidine (Catapressan 0.15 mg/mL, Boehringer Ingelheim, Germany) and morphine (morphine HCl 40 mg/mL, Sterop, Belgium) at 0.003 and 0.417 mg/mL, respectively, was evaluated by using five polypropylene syringes of 48 mL. The high concentration admixture consisted of 0.032 mg/mL clonidine and 4.286 mg/mL morphine HCl and was evaluated by using five polypropylene syringes of 14 mL. All syringes were stored for 30 days at 5°C±3°C. Periodic samples were visually and microscopically examined to observe any particle appearance or colour change. pH and absorbance at three wavelengths (350, 410 and 550 nm) were monitored. The concentrations were measured by ultra-high performance liquid chromatography-photodiode array detection.
RESULTS
During the 30 days, there was no change in colour or appearance of opacity, turbidity or precipitation, and pH remained stable. The low and high concentration admixtures were considered chemically stable since the lower limit of the 90% CI remained superior to 90% of the initial concentration. Concentration measurements showed that the degradation rate was less than 1% over 10 days for each component in both admixtures.
CONCLUSIONS
The admixture of clonidine and morphine HCl at low and high concentrations in polypropylene syringes appeared to be physically and chemically stable throughout the study period of 30 days at 5°C±3°C. In conclusion, the admixture can be prepared in advance under aseptic conditions by a centralised intravenous additive service in the pharmacy department.
Topics: Humans; Clonidine; Polypropylenes; Syringes; Analgesics, Opioid; Morphine Derivatives; Drug Stability
PubMed: 34758972
DOI: 10.1136/ejhpharm-2021-002940 -
Acta Cirurgica Brasileira Apr 2012To evaluate the healing process of a defect in the ventral abdominal wall of rats, comparing the polypropylene and polypropylene/poliglecaprone meshes on the 30(th) and... (Comparative Study)
Comparative Study
PURPOSE
To evaluate the healing process of a defect in the ventral abdominal wall of rats, comparing the polypropylene and polypropylene/poliglecaprone meshes on the 30(th) and 60(th) postoperative day.
METHODS
Thirty two Wistar rats were submitted to a ventral abdominal wall defect, with integrity of the parietal peritoneum. In the repair, were used polypropylene (group A) and polypropylene/poliglecaprone (group B) meshes. The groups were subdivided into four subgroups of eight animals euthanized on the 30(th) (A30 and B30) and 60(th) postoperative day (A60 and B60). Fragments of the abdominal wall of the animals were submitted to macroscopic, tensiometric and histological evaluations.
RESULTS
The tensiometry on subgroup A30 showed a mean average break point of 0.78 MPa and in A60, 0.66 Mpa. In subgroup B30 it was 0.84 MPa and in B60, 1.27 Mpa. The score of the inflammatory process showed subacute phase on A30 and B30 sub-groups and chronic inflammatory process in subgroups A30 and 60B.
CONCLUSIONS
The tensile strength was higher on the wall repaired by polypropylene/poliglecaprone mesh in the 60(th) post-operative day. Histology showed higher concentration of fibrosis on the surface of the polypropylene mesh with a tendency to encapsulation. In polypropylene/poliglecaprone subgroups the histology showed higher concentration of fibrosis on the surface of mesh filaments.
Topics: Abdominal Wall; Animals; Biocompatible Materials; Dioxanes; Male; Microscopy, Electron, Scanning; Polyesters; Polypropylenes; Rats; Rats, Wistar; Surgical Mesh; Time Factors
PubMed: 22534804
DOI: 10.1590/s0102-86502012000400004 -
Biomaterials Advances May 2024Currently, in vitro testing examines the cytotoxicity of biomaterials but fails to consider how materials respond to mechanical forces and the immune response to them;...
Currently, in vitro testing examines the cytotoxicity of biomaterials but fails to consider how materials respond to mechanical forces and the immune response to them; both are crucial for successful long-term implantation. A notable example of this failure is polypropylene mid-urethral mesh used in the treatment of stress urinary incontinence (SUI). The mesh was largely successful in abdominal hernia repair but produced significant complications when repurposed to treat SUI. Developing more physiologically relevant in vitro test models would allow more physiologically relevant data to be collected about how biomaterials will interact with the body. This study investigates the effects of mechanochemical distress (a combination of oxidation and mechanical distention) on polypropylene mesh surfaces and the effect this has on macrophage gene expression. Surface topology of the mesh was characterised using SEM and AFM; ATR-FTIR, EDX and Raman spectroscopy was applied to detect surface oxidation and structural molecular alterations. Uniaxial mechanical testing was performed to reveal any bulk mechanical changes. RT-qPCR of selected pro-fibrotic and pro-inflammatory genes was carried out on macrophages cultured on control and mechanochemically distressed PP mesh. Following exposure to mechanochemical distress the mesh surface was observed to crack and craze and helical defects were detected in the polymer backbone. Surface oxidation of the mesh was seen after macrophage attachment for 7 days. These changes in mesh surface triggered modified gene expression in macrophages. Pro-fibrotic and pro-inflammatory genes were upregulated after macrophages were cultured on mechanochemically distressed mesh, whereas the same genes were down-regulated in macrophages exposed to control mesh. This study highlights the relationship between macrophages and polypropylene surgical mesh, thus offering more insight into the fate of an implanted material than existing in vitro testing.
Topics: Humans; Materials Testing; Surgical Mesh; Polypropylenes; Biocompatible Materials; Macrophages; Urinary Incontinence, Stress
PubMed: 38377947
DOI: 10.1016/j.bioadv.2024.213800 -
Hernia : the Journal of Hernias and... Aug 2014Despite the vast selection of brands available, nearly all synthetic meshes for hernia surgery continue to use one or other of three basic materials: polypropylene,... (Review)
Review
PURPOSE
Despite the vast selection of brands available, nearly all synthetic meshes for hernia surgery continue to use one or other of three basic materials: polypropylene, polyester and ePTFE. These are used in combination with each other or with a range of additional materials such as titanium, omega 3, monocryl, PVDF and hyaluronate. This systematic review of all experimental and clinical studies is aimed at investigating whether titanized meshes confer advantages over other synthetic meshes in hernia surgery.
MATERIALS AND METHODS
A search of the medical literature from 2002 to 2012, as indexed by Medline, was performed, using the PubMed search engine (http://www.pubmed.gov). The search terms were: hernia mesh, titanium coating, lightweight mesh, TiMesh, mesh complications. All papers were graded according to the Oxford hierarchy of evidence.
RESULTS
Patients operated on with the Lichtenstein technique performed using the lightweight titanium-coated mesh have a shorter convalescence than those with the heavy-weight mesh Prolene. For inguinal hernias operated on with the TAPP technique and using a lightweight titanium-coated mesh in comparison to a heavy-weight Prolene mesh, the early postoperative convalescence seems to improve. Titanized meshes do exhibit a negative effect on sperm motility 1 year after a TEP operation, but not after 3 years. The laparoscopic IPOM technique with a titanium-coated polypropylene mesh was associated with less postoperative pain in the short term, lower analgesic consumption and a quicker return to everyday activities compared with the Parietex composite mesh.
CONCLUSION
In clinical studies, the titanium-coated polypropylene mesh shows in inguinal hernia repair certain benefits compared with the use of older heavy-weight meshes.
Topics: Biocompatible Materials; Hernia, Inguinal; Herniorrhaphy; Humans; Polypropylenes; Surgical Mesh; Titanium
PubMed: 24253381
DOI: 10.1007/s10029-013-1187-3