Polypropylene fiber was equally mixed into alkali-activated slag fly ash geopolymer in order to ensure the filling effect of mine goaf and improve the stability of cemented gangue paste filling material with ecological matrix. Triaxial compression tests were then conducted under various conditions. The mechanical properties and damage characteristics of composite paste filling materials are studied, and the damage evolution model of paste filling materials under triaxial compression is established, based on the deviatoric stress-strain curve generated by the progressive failure behavior of samples. Internal physical and chemical mechanisms of the evolution of structure and characteristics are elucidated and comprehended via the use of SEM-EDS and XRD micro-techniques. The results show that the fiber can effectively improve the ultimate strength and the corresponding effective stress strength index of the sample within the scope of the experimental study. The best strengthening effect is achieved when the amount of NaOH is 3% of the mass of the solid material, the amount of fiber is 5‰ of the mass of the solid material, and the length of the fiber is about 12 mm. The action mode of the fiber in the sample is mainly divided into single-grip anchoring and three-dimensional mesh traction. As the crack initiates and develops, connection occurs in the matrix, where the fiber has an obvious interference and retardation effect on the crack propagation, thereby transforming the brittle failure into a ductile failure and consequently improving the fracture properties of the ecological cementitious coal gangue matrix. The theoretical damage evolution model of a segmented filling body is constructed by taking the initial compaction stage end point as the critical point, and the curve of the damage evolution model of the specimen under different conditions is obtained. The theoretical model is verified by the results from the triaxial compression test. We concluded that the experimental curve is in good agreement with the theoretical curve. Therefore, the established theoretical model has a certain reference value for the analysis and evaluation of the mechanical properties of paste filling materials. The research results can improve the utilization rate of solid waste resources.

Poor waste management and unsustainable institutional and individual behaviors, have led to the accumulation of plastic litter in many habitats worldwide. Assessment of plastic pollution in Kenyan marine environment was conducted focusing on the impact of banning the single-use plastic carrier bags in Kenya. The quantification, composition, and distribution of plastics were determined at nine (9) beaches along Kenyan coastline using standing stock method. A total of 750 plastic items were collected and categorized with only 47 pieces being single-use plastic carrier bags. A great number of plastics (n = 383), were identified by their original use, with packaging plastics being the most common (n = 155). Macroplastics were the overall dominant plastics at 76%, mesoplastics, 21% and microplastics, 3%, which were altogether dominated by low-density polyethylene (LDPE) at (46%), followed by polypropylene (PP), 30%; polyethylene tetraphthalate (PET), 9%; polyvinyl chloride (PVC), 8%; and polystyrene (PS), 7%. The absence of identifiable single-use plastic carrier bags in 6 out of 9 beaches signified the effectiveness of the ban in Kenya. Monitoring of trends and sources of plastic debris is encouraged to help enhance the science-policy linkage aimed at reducing marine plastic pollution.

BACKGROUND: Neovascular glaucoma (NVG) is a secondary glaucoma with a poor visual prognosis. Trabeculectomy with antifibrotic agents, glaucoma drainage devices (GDDs), and cyclo-destructive procedures are recommended in patients who are refractory to medical management. However, due to the poor success rate of conventional trabeculectomy and the higher cost of GDDs, alternative procedures need to be looked at.
OBJECTIVE: To compare the surgical outcomes and economic aspects of a newly developed polypropylene suture bed-based modified trabeculectomy to Ahmed glaucoma valve (AGV) implantation for NVG.
METHODS: It was a prospective interventional study conducted at a tertiary care center between 2018 and 2020. Consecutive patients with NVG with a minimum follow-up of 18 months were included. Surgical outcomes are mainly based on intraocular pressure (IOP) control and the cost of surgery.
RESULTS: Sixty eyes were included out of which 40 (60.6%) underwent modified trabeculectomy and 20 (33.7%) underwent AGV. At the final follow-up, no significant difference (P < 0.05) was found between the surgical outcomes of both groups. The complete success rate (IOP < 21 mm Hg without antiglaucoma medications) was 60 and 65% while the qualified success rate (IOP < 21 mm Hg with antiglaucoma medications) was 30 and 25% in modified trabeculectomy and AGV groups, respectively, at final follow-up. The cost of surgery was significantly higher in the AGV group (P < 0.0001).
CONCLUSIONS: Modified trabeculectomy as described might be a better alternative for NVG eyes.

The adsorption/desorption of Rhodamine B (RhB) on Polystyrene (PS), polypropylene (PP), and polyvinyl chloride (PVC) microplastics (MPs) was investigated in this study. The results showed that RhB adsorption on the selected MPs was fast. The adsorption coefficients (Kd) of RhB were 2036 ± 129, 1557 ± 91, and 63 ± 8.5 L kg- 1 for PS, PP, and PVC, respectively. RhB adsorption on PS and PP increased with increasing temperature and decreasing ionic strength, whereas RhB adsorption on PVC showed a completely opposite trend. The binding strength of RhB on the three types of MPs was weak as demonstrated by the high total desorption percentage, which ranged from 79.59 ~ 89.39%. This study shows that PP and PS MPs can accumulate RhB in the aquatic environment and their potential combined toxic risks should be taken seriously.

BACKGROUND: Duramesh (Mesh Suture Inc., Chicago, IL) is a new suturing concept, combining the principles of mesh with the precision, flexibility, and versatility of a suture, suitable also for abdominal rectus diastasis (ARD) correction.
OBJECTIVE: This prospective research aimed to compare mesh with the standard polypropylene suture plication for rectus diastasis repair with regard to safety (infection, seroma, hematoma, surgical wound dehiscence, and fistula rates and hospital stay); effectiveness (ARD recurrence by ultrasound sonography, palpability of the muscular suture, surgical time, and postoperative pain evaluation); and satisfaction of the patients based on the BODY-Q, a patient-reported outcome measure.
METHODS: Sixty-five of the initial 70 patients who underwent rectus diastasis repair with a 6-month follow-up were randomly divided into 2 groups, comprising 33 patients treated with Duramesh and 32 patients treated with standard 0 polypropylene suture plication. Data regarding infection, seroma, hematoma, surgical wound dehiscence, and fistula rates; hospital stay; ARD recurrence; palpability of the muscular suture; surgical time; postoperative pain evaluation (measured by visual analog scale, or VAS); and the BODY-Q were analyzed by Prism 9 (GraphPad Software Inc., San Diego, CA).
RESULTS: No significant differences were reported between the 2 groups with regard to infection, seroma, hematoma, surgical wound dehiscence, and fistula rates and hospital stay. The mesh decreased the time required to perform plication compared with standard polypropylene detached sutures. No statistically significant differences were found with respect to the VAS and BODY-Q data.
CONCLUSIONS: Duramesh 0 application for rectus diastasis repair is safe and effective without compromising aesthetic improvement when compared with standard 0 polypropylene plication.
METHODS:

BACKGROUND: The SARS-CoV-2 pandemic resulted in shortages of supplies, which limited the use of extracorporeal membrane oxygenation (ECMO) support. As a contingency strategy, polypropylene (PP) oxygenation membranes were used. This study describes the clinical outcomes in patients on ECMO with PP compared to poly-methylpentene (PMP) oxygenation membranes.
METHODS: Retrospective cohort of patients in ECMO support admitted between 2020 and 2021.
RESULTS: A total of 152 patients with ECMO support were included, 71.05% were men with an average age of 42 (SD 9.91) years. Veno-venous configuration was performed in 75.6% of cases. The PP oxygenation membranes required more changes 22 (63.1%), than the PMP Sorin® 24 (32,8%) and Euroset® 15 (31,9%) (p.0.022). The main indication for membrane change was low oxygen transfer for PP at 56.2%, Sorin® at 50%, and Euroset® at 14.8%. Renal replacement therapy was the most frequent complication with PP membrane in 22 patients (68.7%) Sorin® 25 patients (34.2%), and Euroset® 15 patients (31.9%) (p 0.001) without statistically significant differences in mortality.
CONCLUSIONS: PP oxygenation membranes was a useful and feasible strategy. It allowed a greater disponibility of ECMO support for critically ill in a situation of great adversity during the SARS-CoV-2 pandemic.

OBJECTIVE: Polypropylene meshes (PM) used in pelvic organ prolapse surgery are being withdrawn from the market. Although concerns about the usage of PMs in stress incontinence surgery have been raised, it is still one of the best methods of curing stress urinary incontinence. With advancements in stem cell-based therapies, especially mesenchymal stem cells (MSCs), it is believed that coating the synthetic meshes with MSCs may minimize excessive tissue reactions ultimately leading to clinical problems such as pain, erosion or extrusion of the implanted material. In our study we tried to show the possibility of coating the PM with placenta-derived MSCs.
METHODS: Mesenchymal stem cells obtained from six placentas were isolated, cultured, and identified. MSCs were then soaked in either fibronectin or collagen prior to co-culturing with strips of PMs. One group is used as a control, and hence was not pretreated before co-culturing. Specimens were fixed and stained with both Gram and hematoxylin and eosin and marked with Vybran Dil and DAPI. All preparations were examined under a light microscope. The IMAGEJ program was utilized to determine the surface area of meshes coated with MSCs.
RESULTS: We clearly showed that PMs can be coated successfully with placenta-derived MSCs. The percentage of the coated area is significantly increased when meshes were pretreated with fibronectin or collagen (p<0.0001).
CONCLUSIONS: Placenta-derived MSCs can successfully coat PMs. The immunomodulatory properties of MSCs, which may be of great advantage in preventing the side effects of meshes, should be tested by in vivo and hopefully human studies before clinical applications.

This study presents an in vitro analysis of the bactericidal and cytotoxic properties of hybrid films containing nickel oxide (NiO) and nickel ferrite (NiFe2O4) nanoparticles embedded in polypropylene (PP). The solvent casting method was used to synthesize films of PP, PP@NiO, and PP@NiFe2O4, which were characterized by different spectroscopic and microscopic techniques. The X-ray diffraction (XRD) patterns confirmed that the small crystallite sizes of NiO and NiFe2O4 NPs were maintained even after they were incorporated into the PP matrix. From the Raman scattering spectroscopy data, it was evident that there was a significant interaction between the NPs and the PP matrix. Additionally, the Scanning Electron Microscopy (SEM) analysis revealed a homogeneous dispersion of NiO and NiFe2O4 NPs throughout the PP matrix. The incorporation of the NPs was observed to alter the surface roughness of the films; this behavior was studied by atomic force microscopy (AFM). The antibacterial properties of all films were evaluated against Pseudomonas aeruginosa (ATCC®: 43636™) and Staphylococcus aureus (ATCC®: 23235™), two opportunistic and nosocomial pathogens. The PP@NiO and PP@ NiFe2O4 films showed over 90% bacterial growth inhibition for both strains. Additionally, the effects of the films on human skin cells, such as epidermal keratinocytes and dermal fibroblasts, were evaluated for cytotoxicity. The PP, PP@NiO, and PP@NiFe2O4 films were nontoxic to human keratinocytes. Furthermore, compared to the PP film, improved biocompatibility of the PP@NiFe2O4 film with human fibroblasts was observed. The methodology utilized in this study allows for the production of hybrid films that can inhibit the growth of Gram-positive bacteria, such as S. aureus, and Gram-negative bacteria, such as P. aeruginosa. These films have potential as coating materials to prevent bacterial proliferation on surfaces.

BACKGROUND: Hernia repair using prosthetic mesh materials has become the preferred method of repair, as the recurrence rates are much lower than with conventional repair techniques. The aim of this retrospective study was to compare open small- and medium-sized abdominal wall hernia repair with flat patch mesh versus three-dimensional mesh (plug) in terms of recurrence and complication rates.
METHODS: The medical records of 300 patients who underwent abdominal wall hernia repair using flat patch mesh versus three-dimensional mesh between January 2010 to December 2015 were reviewed. All patients were followed up after 1 month, 3 month and 1 year. The rate of recurrence, and short-term postoperative complications such as incidence of Surgical Site Infections (SSIs), hematoma and seroma were evaluated.
RESULTS: Short-term follow-up data were available for all patients. The first group was composed of 150 patients that were treated with a flat polypropylene mesh (68% presened umbilical hernia and 32% presented epigastric hernia). The second group was composed of 150 patients that were treated with a three-dimensional polypropylene mesh (60% presented umbilical hernia and 40% presented epigastric hernia). The majority of postoperative (1-month) complications were wound related, representing superficial SSI or seroma. Our results showed a statistically significant reduction of SSIs [3 (2%) vs 13 (8.6%); p = 0.038] and seroma [2 (1.3%) vs 12 (8%); p = 0.030] in the group of patients treated with plugs compared to flat-mesh group. There was no statistically significant difference in hernia recurrences.
CONCLUSIONS: Usage three-dimensional mesh for open small- and medium-sized umbilical or epigastric hernia repair represents a feasible and safe technique that significantly lowers the incidence of complications such as SSIs and seroma. Furthermore, compared to flat patch mesh, plugs displayed non-inferiority in terms recurrence. Further, well-designed clinical trials could be realized to investigate possible applications of plugs in treatment of small- and medium-sized umbilical and epigastric hernias.
BACKGROUND: Mesh, Umbilical Hernia.
La riparazione dell’ernia utilizzando materiali a rete protesica è diventata il metodo di riparazione preferito, poiché i tassi di recidiva sono molto inferiori rispetto alle tecniche di riparazione convenzionali. Lo scopo di questo studio retrospettivo era di confrontare la riparazione dell’ernia della parete addominale di piccole e medie dimensioni con patch di rete a piatto rispetto a rete tridimensionale (plug) in termini di tassi di recidiva e complicanze. Sono state esaminate le cartelle cliniche di 300 pazienti sottoposti a riparazione di ernia della parete addominale utilizzando un patch di rete a piatto rispetto a un plug di rete tra gennaio 2010 e dicembre 2015. Tutti i pazienti sono stati seguiti dopo 1 mese, 3 mesi e 1 anno. Sono stati valutati il tasso di recidiva e le complicanze postoperatorie a breve termine come l’incidenza di infezioni del sito chirurgico (SSI), ematoma e sieroma. RISULTATI: I dati di follow-up a breve termine sono stati disponibili per tutti i pazienti. Il primo gruppo era composto da 150 pazienti trattati con una rete a piatto in polipropilene (il 68% per ernia ombelicale e il 32% per ernia epigastrica). Il secondo gruppo era composto da 150 pazienti trattati con plug di rete in polipropilene (il 60% per ernia ombelicale e il 40% per ernia epigastrica). La maggior parte delle complicanze postoperatorie (ad 1 mese) erano correlate alla ferita, rappresentando SSI superficiali o sieroma. I nostri risultati hanno mostrato una riduzione statisticamente significativa delle SSI [3 (2%) vs 13 (8,6%); p = 0,038] e sieroma [2 (1,3%) vs 12 (8%); p = 0,030] nel gruppo di pazienti trattati con plug rispetto al gruppo con rete a piatto. Non c’è stata alcuna differenza statisticamente significativa nelle recidive di ernia. DISCUSSIONE: L’utilizzo di un plug di rete per la riparazione di ernia ombelicale o epigastrica di piccole e medie dimensioni rappresenta una tecnica fattibile e sicura che riduce significativamente l’incidenza di complicanze come SSI e sieroma. Inoltre, rispetto al patch di rete a piatto, i plug hanno mostrato una analogie in termini di recidiva. Ulteriori studi clinici ben progettati potrebbero essere realizzati per studiare le possibili applicazioni dei plugs nel trattamento delle ernie ombelicali ed epigastriche di piccole e medie dimensioni.

BACKGROUND: Medical syringes are widely used in hospitals to store and administer drugs, and the contact time between the drugs and these syringes can vary from a few minutes to several weeks like for pharmaceutical preparations. The aim of this comparative study was to evaluate the potential sorption phenomena occurring between three drugs (paracetamol, diazepam and insulin aspart) and polypropylene syringes (PP) or syringes made of Cyclic Olefin Copolymer (COC).
METHODS: 50 mL 3-part syringes made of either COC with crosslinked silicone on the barrel inner surface (COC-CLS) and a bromobutyl plunger seal, or PP lubricated with silicone oil (PP-SOL) with a polyisoprene plunger seal were used.
RESULTS: COC-CLS syringes induced less sorption of diazepam and insulin than PP-SOL syringes and the plunger seal material seemed to be the main cause of these interactions. An alkalinization of the medications in contact with the PP-SOL syringes was observed. It could be caused by leachable compounds and should be investigated further.
CONCLUSIONS: This work shows once again that it is essential to consider content-container interactions to help improve the safe use of parenteral drugs.