Assessing the impact of simulated ocean acidification on the photodegradation of selected microplastics.

This study investigated the impact of ocean acidification on the photodegradation of three microplastics (MPs): polypropylene (PP), expanded polystyrene (EPS), and ethylene-vinyl acetate (EVA), under accelerated UV radiation at three pH levels (i.e., 8.1, 7.8, and 7.5), simulating marine conditions. The acidification system simulated current and projected future environmental conditions. As expected, an increase in partial pressure of CO2, total inorganic carbon, bicarbonate ion, and CO2 resulted in more acidic pH levels, with the reverse being true for the carbonate ion. Structural changes of MPs were evaluated, revealing that all weathered samples underwent higher degradation rate compared to the virgin samples. The oxidation state and crystallinity of PP and EVA MPs were higher in samples exposed to the lowest pH, whereas no significant increase in the degradation rate of EPS samples was observed. Saltwater acidification in this study contributed to enhance the photo-oxidation of MPs depending on their polymeric composition.

Comprehensive clinical and histological evaluation of bovine hydroxyapatite bone graft with polypropylene membrane versus leukocyte- and platelet-rich fibrin for alveolar preservation after tooth extraction.

BACKGROUND: Osseointegrated implant placement in the ideal prosthetic position necessitates a sufficient residual alveolar ridge. Tooth extraction and the subsequent healing process often lead to bony deformities, characterized by a reduction in alveolar ridge height and width, resulting in unfavorable ridge architecture for dental implant placement. Several materials, including allografts, alloplastics, xenografts, and autogenous bone, are commonly used to address these concerns. In this context, leucocyte- and platelet-rich fibrin (L-PRF) emerges as a promising solution. METHODS: This case report aims to compare the clinical and histological efficacy of bovine hydroxyapatite bone graft covered with polypropylene membrane (BHAG-PM) and leucocyte- and platelet-rich fibrin (L-PRF) in preserving dental alveoli following tooth extraction. Extraction, graft placement in the alveoli, and the anterior border between extracted elements were performed for both treatment groups. RESULTS: Up to 24 months of follow-up revealed satisfactory and comparable clinical and histological outcomes. These results suggest that both BHAG-PM and L-PRF effectively promote alveolar preservation, paving the way for ideal implant placement. CONCLUSIONS: In general, bone-substitute materials are effective in reducing alveolar changes after tooth extraction. Xenograft materials should be considered as among the best of the available grafting materials for alveolar preservation after tooth extraction. Both techniques effectively preserve the alveolar bone and facilitate the placement of osseointegrated implants in ideal positions, paving the way for successful oral rehabilitation.

Tumor de células gigantes esternal: esternectomía total y reconstrucción con barras de titanio más malla de polipropileno / Sternal Giant Cell Tumor: Total Sternectomy and Reconstruction with Titanium Rods Plus Polypropylene Mesh

El tumor de células gigantes (TCG) constituye un tumor óseo benigno relativamente frecuente. Se caracteriza por ser localmente agresivo y el lugar de presentación más frecuente es a nivel del esqueleto axial (fémur distal o tibia proximal). Hasta la actualidad, existen escasos informes de presentaciones atípicas, como a nivel del esternón. En este informe, se presenta el caso de una paciente mujer de 24 años que presenta tumoración indurada a nivel de la región esternal de crecimiento progresivo asociado a dolor. Los hallazgos radiológicos revelan tumoración osteolítica que tiene como origen el cuerpo del esternón y lo compromete casi en su totalidad. Este se proyecta hacia las partes blandas y llega al plano superficial. Debido a la extensión de la enfermedad y al compromiso extenso en el cuerpo del esternón, se realiza la resección del cuerpo y manubrio esternal. El defecto es reconstruido con malla de polipropileno, barras de titanio, parche de epiplón y autoinjerto de piel; se obtiene una adecuada estabilidad de la caja torácica y resultados estéticos favorables. El caso tiene un adecuado manejo oncológico puesto que la resección es completa con márgenes microscópicos libres (resección R0).

Giant cell tumor (GCT) constitutes a relatively common benign bone tumor, characteri-zed by its local aggressiveness. The most frequent site of occurrence is in the axial ske-leton (distal femur or proximal tibia). To date, there have been few reports of atypical presentations, such as at the level of the sternum. In this report, we present the case of a 24-year-old female patient who presented with an indurated mass in the sternal region, progressively growing and associated with pain. Radiological findings revealed an osteolytic mass originating from the body of the sternum, involving almost its entire extent and projecting into the soft tissues, reaching the superficial plane. Due to the extent of the disease and the extensive involvement of the sternal body, resection of the body and manubrium of the sternum was performed. The surgical defect was reconstructed with polypropylene mesh, titanium bars, an omental patch and a skin graft, achieving adequate stability of the thoracic cage and favorable cosmetic results.

[Design and application of a device for radiographic projection of the tibio-astragalangeal mortise]. / Diseño y aplicación de dispositivo para proyección radiográfica de la mortaja tibio-astragalina.

INTRODUCTION: ligamentous injuries of the distal tibiofibular syndesmosis resulting in its opening are common occurrences in traumatology; however, their diagnosis poses a challenge for orthopedic surgeons. The tibioastragaloid mortise radiograph view is the most commonly used method for diagnosing this type of injury, but its reliability is compromised due to variations in ankle positioning during the study, which often depend on the operator. OBJECTIVE: to demonstrate that the designed device achieves a correct and consistent radiographic image of the distal tibiofibular syndesmosis in the mortise view. MATERIAL AND METHODS: we present a prospective, longitudinal, observational study. We designed a polypropylene device that maintains the ankle at 90 degrees of dorsiflexion and 15 degrees of internal rotation. The device was used to take mortise view radiographs of healthy ankles, and corresponding measurements were taken to assess the syndesmosis. RESULTS: we evaluated a total of 46 radiographs of healthy ankles, with a predominance of left ankles. The obtained measurements were as follows: anterior tibiofibular distance (ATFD) ranged from 3 to 6 mm, posterior tibiofibular distance (PTFD) ranged from 1 to 3 mm, tibiofibular clear space (TFCS) ranged from 2 to 3 mm, and a Merle D'Aubigne ratio of 2:1 was observed in all ankles. When comparing the measurements obtained with those established by Harper and Keller, no statistically significant difference was found (2 < 5). CONCLUSION: with the use of the designed device, we achieved a correct and consistent radiographic image of the mortise and the distal tibiofibular syndesmosis.

INTRODUCCIÓN: las lesiones ligamentarias de la sindesmosis tibioperonea distal que ocasionan apertura de la misma son muy frecuentes en traumatología; sin embargo, su diagnóstico es un reto para el cirujano ortopedista. La radiografía de la mortaja tibioastragalina es el método más utilizado para el diagnóstico de este tipo de lesiones, pero es poco confiable ya que la posición del tobillo durante el estudio suele variar dependiendo del operador. OBJETIVO: demostrar que con el uso del dispositivo diseñado se logra una imagen radiográfica correcta y constante de la sindesmosis tibioperonea distal en la proyección de la mortaja. MATERIAL Y MÉTODOS: estudio prospectivo, longitudinal y observacional. Diseñamos un dispositivo de polipropileno que mantiene el tobillo a 90 grados de dorsiflexión y rotación interna de 15 grados. Aplicamos el dispositivo para tomar radiografías de la mortaja en tobillos sanos y les realizamos las mediciones correspondientes para valorar la sindesmosis. RESULTADOS: valoramos un total de 46 radiografías de tobillos sanos, con un predominio de tobillos izquierdos. Las mediciones conseguidas fueron las siguientes: espacio tibioperoneo (ETP) de 3 a 6 mm, la superposición tibioperonea (STP) de 1 a 3 mm, espacio astrágalo-tibial medial (EATM) de 2 a 3 mm y una relación de Merle D'Aubigne de 2:1 en todos los tobillos. Al comparar las mediciones obtenidas con las establecidas por Harper y Keller, no se encontró una diferencia estadísticamente significativa (2 < 5). CONCLUSIÓN: con el uso del dispositivo diseñado, obtuvimos una correcta y constante imagen radiográfica de la mortaja y la sindesmosis tibioperonea distal.

How to Measure Polymer Degradation? An Analysis of Authors' Choices When Calculating the Carbonyl Index.

The carbonyl index aims to measure the degradation level and is used in plastic degradation research as a proxy for the general degradation level of collected plastic pieces. According to the choices for carbonyl index calculation, comparison using this index is prevented and must be unveiled by the authors, which does not always happen. In order to study the proper usage of the carbonyl index, regarding the choice of the reference band and the usage of the band intensity or the absorption area, we systematically reviewed the methodologies used for polypropylene as a case study. Based on 95 studies gathered from 2000 to 2024, two main methods were used to determine the carbonyl index: the ratio between the carbonyl band area and the reference band area (33.68%) and the ratio between the highest intensity of the carbonyl band and the reference band (66.31%). The reference band of choice and the type of calculation method produce different carbonyl index values for the same spectra and mean different information, preventing comparison among works with different calculations.

Experiencia de la histeropexia vaginal, usando prótesis de polipropileno / Experience of vaginal hysteropexy, using polypropylene prosthesis

Introducción: El prolapso de órganos pélvicos (POP) o distopia genital, es el descenso o desplazamiento de los órganos del suelo pélvico a través del canal vaginal o fuera de este. Objetivo: Evaluar los resultados de la histeropexia vaginal en la corrección quirúrgica del prolapso genital apical grado III o IV, usando prótesis de polipropileno; además describir la tasa de éxito, recurrencias y complicaciones. Método: Estudio de cohorte, en 42 mujeres sometidas a histeropexia vaginal (histero-cistopexia ortotópica) mediante prótesis de polipropileno (Splentis®), entre 2016 y 2021. Se realizaron tres evaluaciones postoperatorias (tres, seis y 12 meses). Se hizo muestreo no probabilístico. Se utilizó estadística descriptiva. Resultados: La edad media fue de 56,19 ± 9,27 años. El tiempo quirúrgico de 58,95 ± 13,74 minutos, el sangrado quirúrgico de 119,85 ± 68,73 ml. La tasa de éxito a los 12 meses fue del 90,47%. La recurrencia del prolapso apical fue del 4,76% a los seis meses y del 9,52% a los 12 meses; el de compartimento anterior a los seis meses arrojó un 7,14%, frente al 11,9% a los 12 meses. El 14,28% de las pacientes presentaron complicaciones menores. La incidencia de incontinencia urinaria de esfuerzo a los 12 meses fue del 16,66%. Conclusiones: la histeropexia vaginal es un procedimiento efectivo y seguro, con bajas tasas de recurrencias o complicaciones. Es importante que se sigan haciendo estudios con mejores diseños estadísticos.

Introduction: Pelvic organ prolapse (POP), or genital dystopia, is the descent or displacement of pelvic floor organs through the vaginal canal or outside of it. Objective: To evaluate the results of vaginal hysteropexy in the surgical correction of grade III or IV apical genital prolapse, using polypropylene prosthesis; also describe the success rate, recurrences and complications. Method: Cohort study in 42 women undergoing vaginal hysteropexy (orthotopic hystero-cystopexy) using a polypropylene prosthesis (Splentis®); between 2016 and 2021. Three postoperative evaluations were carried out (three, six and twelve months). Non-probabilistic sampling was done. Descriptive statistics were used. Results: The mean age was 56.19 ± 9.27 years. Surgical time of 58.95 ± 13.74 minutes, surgical bleeding of 119.85 ± 68.73 ml. The success rate after twelve months was 90.47%. Apical prolapse recurrence was 4.76% at six months and 9.52% at twelve months; that of the previous compartment, after six months it showed 7.14%, compared to 11.9% after twelve months; 14.28% of the patients presented minor complications. The incidence of stress urinary incontinence, at twelve months, was 16.66%. Conclusions: Vaginal hysteropexy is an effective and safe procedure, with low rates of recurrence or complications. It is important that studies continue to be carried out with better statistical designs.

Outcomes of ECMO support with polypropylene membrane during pandemic times: a retrospective cohort study.

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. CONCLUSION: 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.

Quiste meniscal posterior a la sutura meniscal con monofilamento de polipropileno / Meniscal cyst after polypropylene monofilament suture

Introducción: la función del tejido meniscal es fundamental en la transmisión y distribución de cargas de la rodilla. En casos de lesión meniscal, la sutura es el tratamiento quirúrgico de elección, y pueden utilizarse diferentes materiales para realizarla. El objetivo del trabajo es analizar la aparición de quistes meniscales sintomáticos con el uso de sutura no reabsorbible del tipo monofilamento de polipropileno en un grupo de pacientes con lesiones en asa de balde y evaluar el material de sutura como causal de quiste.Materiales y métodos: se realizó un estudio retrospectivo de un grupo de pacientes con lesiones en asa de balde suturadas con material no reabsorbible del tipo monofilamento de polipropileno (MP) y sutura de alta resistencia de polietileno de ultra alto peso molecular UHMWPE (SAR) y se analizó la presencia de quiste meniscal sintomático como complicación. Los criterios de inclusión para este estudio fueron pacientes con lesiones en asa de balde a los cuales se les realizó sutura meniscal con técnicas combinadas con material de tipo no reabsorbible. Se excluyeron pacientes con lesiones que no fueran con patrón en asa de balde o a los cuales se les hizo sutura meniscal todo-adentro únicamente.Resultados: un total de veinticinco pacientes, quince de sexo masculino y diez de sexo femenino. La edad media del grupo evaluado fue de 27.8 años. El 72% fue suturado con sutura de alta resistencia (SAR) mientras que a un 28% se les realizó sutura con monofilamento de polipropileno (MP). El 92% de las lesiones se presentaron en el menisco interno. Se observaron tres pacientes con quistes meniscales sintomáticos asociados a la sutura MP, los cuales fueron tratados quirúrgicamente con buena evolución. Conclusión: identificamos en nuestra serie que la aparición de quistes sintomáticos se relaciona estrechamente con el uso de monofilamento de polipropileno (MP). Consideramos la utilización de hilos no reabsorbibles de alta resistencia (polietileno de ultra alto peso molecular UHMWPE) como la primera opción para realizar las suturas meniscales por la baja tasa de complicación y los buenos resultados. Nivel de Evidencia: IV

Introduction: The function of the meniscal tissue is fundamental in the transmission and distribution of knee loads. In cases of meniscal injury, suturing is the surgical treatment of choice, and different materials can be used to perform it. The aim of the work is to analyze the appearance of symptomatic meniscal cysts with the use of non-absorbable polypropylene monofilament suture in a group of patients with bucket handle injuries and to evaluate the suture material as a cause of the cyst. Materials and methods: a retrospective study was carried out on a group of patients with bucket-handle injuries sutured with non-absorbable polypropylene monofilament (MP) material and high-strength ultra-high molecular weight UHMWPE polyethylene (SAR) suture and the presence of a symptomatic meniscal cyst as a complication was analyzed. The inclusion criteria for this study were patients with bucket-handle injuries in whom meniscal suture was performed with combined techniques with non-resorbable material. Patients with injuries other than a bucket-handle pattern or who underwent all-in meniscal suturing only were excluded.Results: a total of twenty-five patients, fifteen males and ten females. The average age of the evaluated group was 27.8 years. 72% were sutured with high resistance suture (SAR) while 28% were sutured with polypropylene monofilament (MP). 92% of the injuries occurred in the medial meniscus. Three patients were observed with symptomatic meniscal cysts associated with the MP suture, which were treated surgically with good outcomes. Conclusion: we identified in our series that the appearance of symptomatic cysts is closely related to the use of polypropylene monofilament (MP). We consider the use of high-strength non-absorbable threads (ultra-high molecular weight polyethylene UHMWPE) as the first option to perform meniscal sutures due to the low complication rate and good results. Level of Evidence: IV

Antibacterial and Cytotoxic Study of Hybrid Films Based on Polypropylene and NiO or NiFe2O4 Nanoparticles.

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.

Assessing Endoscopic Suture Performance of Gynecology and Obstetrics Residents Following Methodic Training.

OBJECTIVE: To evaluate the performance of residents in gynecology and obstetrics before and after practicing laparoscopic sutures, to establish when the training shows the best results, in addition to comparing whether being in different years of residency influences this progression. METHODS: A prospective cohort study involving 32 medical residents evaluated with a pretest to establish their previous knowledge in laparoscopic suture. This test consisted of knotting two wires, one made of polypropylene and the other of polyglactin, with a blocking sequence of five semi-knots. We set a 30-minute limit to complete the task. Then, the residents held four training meetings, focusing on suture, Gladiator rule, knot, and symmetries, in addition to executing blocking sequences. A second test to establish progress was performed. RESULTS: Regarding the time spent to make the stiches using polyglactin wire, a statistically significant time improvement (p < 0.01) was observed, with a 10.67-minute pretraining median (mean 12.24 minutes) and a 2.53-minute posttraining median (mean 3.25 minutes). Regarding the stitches with polypropylene wire, a statistically significant time improvement (p < 0.05) was also observed, with a 9.38-minute pretraining median (mean 15.43 minutes) and a 3.65-minute posttraining median (mean 4.54 minutes). A total of 64.2% of the residents had been able to make the knot with polypropylene previously. One hundred percent were able to complete the task in the posttest. CONCLUSION: Model training using the Gladiator rule for laparoscopic suture improves the knotting time with statistically similar performance, regardless of the year of residency, after systematic training.

OBJETIVO: Avaliar a performance de residentes em ginecologia e obstetrícia antes e depois de praticarem suturas laparoscópicas, com o intuito de estabelecer quando o treinamento mostra os melhores resultados, comparando se estar em diferentes da residência influencia essa progressão. MéTODOS: Um estudo coorte prospectivo envolvendo 32 médicos residentes avaliados com um teste pré-treinamento para avaliar seus conhecimentos prévios em sutura laparoscópica. Esse teste consistia em atar nós em dois fios, um de polipropileno e o outro de poliglactina, com uma sequencia de bloqueio de cinco seminós. Definiu-se um limite de 30 minutos para se completar a tarefa. Depois, os residentes tiveram quatro reuniões de treinamento, focadas em sutura, técnica da Regra do Gladiador, nós e simetria, executando, ainda, uma sequência de pontos. Um segundo teste foi feito para avaliar o progresso. RESULTADOS: Com relação ao tempo para realizarem os pontos com fio de poliglactina, uma melhora de tempo estatisticamente significativa (p < 0.01) foi observada, com uma mediana de 10.67 minutos no pré-treinamento (média de 12.24 minutos) e uma mediana de 2.53 minutos no pós-treinamento (média de 3.25 minutos). Com relação ao fio de polipropileno, uma melhora de tempo estatisticamente significativa (p < 0.05) também foi observada, com uma mediana de pré-treinamento de 9.38 minutos (média de 15.43 minutos) e uma mediana de pós-treinamento de 3.65 minutos (média de 4.54 minutos). Um total de 64.2% dos residentes foram capazes de realizar os nós com polipropileno inicialmente. Cem por cento do residentes foram capazes de completar a tarefa no pós-teste. CONCLUSãO: O modelo de treino usando a técnica da Regra do Gladiador para sutura laparoscópica melhora o tempo de atar nós com uma performance estatisticamente similar, não havendo diferenças quanto ao ano da residência, após treinamento sistematizado.

Microbiological characterization of biofilm from different immobilization structures used in submersed aerobic biofilters in domestic effluent treatment at the city of Joinville, Brazil.

The objective of this work was to develop a polymeric structure for a biofiltration unit of domestic effluents through microbiological immobilization, capable of promoting the efficient removal of pollutants, meeting local/national Brazilian standards and/or legislation while providing low environmental impact on their production. Four different structures were tested, namely, polypropylene casings without filling material (TF1); polypropylene casings filled with expanded polystyrene grains (TF2); polypropylene casings, filled with polyurethane foam (TF3); and polypropylene casings, filled with polyvinyl chloride pellets (TF4). A flow of 0.216 m3 d-1 was applied to the system, and the biofilters operated in sequential batches with a hydraulic retention time of 6 h. The efficiency potential of the four immobilization structures was verified regarding biochemical and chemical oxygen demand, total ammoniacal nitrogen and total phosphorus. Microbiological analysis of the formed biofilm, performed with the 16S library sequencing method, with amplification of the 16S rRNA V3 and V3-V4 genomic regions, showed a high diversity of microbiological colonization in the four immobilization structures, with better results and consequently greater community stability in TF2. It is recommended using the filter bed made up of unfilled casings, followed by the one filled with expanded polystyrene grains.

Influence of UV exposure time and simulated marine environment on different microplastic degradation.

This study investigated the influence of environmental factors (UV radiation and salinity) in the degradative process of microplastics (MPs). MPs derived from polypropylene (PP), polystyrene (PS), and ethylene-vinyl acetate (EVA) were subjected to accelerated photodegradation while being submerged in distilled water or artificial seawater. Depending on the polymer, changes in surface properties, new functional chemical group formation and oxidative index, and thermal characteristics of samples were observed. After photodegradation experiments, EVA-MPs samples showed an increase in their thermal resistance, besides the changes in their surface. PP-MPs crystallinity index increased upon exposure to UV radiation. PS samples showed a higher carbonyl and hydroxyl index after 30 h of UV exposure. The methodology exploited applies to any location in the world and can be comparable once considering the total ultraviolet index (UVI). The saline medium increases the crystallinity index of PP and EVA-MPs samples and intensifies the formation of new carbonyl and hydroxyl bonds in EVA-MPs samples. The results showed that several environmental factors should be considered in interpreting MPs photodegradation.

Neo-osteogenesis using an intentionally exposed polypropylene membrane after tooth extraction versus guided bone regeneration technique: a single-blind randomized controlled trial / Neo-osteogénesis utilizando una membrana de polipropileno expuesta intencionalmente después de la extracción del diente versus técnica de regeneración ósea guiada: ensayo clínico aleatorizado ciego / Neo-osteogênese utilizando uma membrana de polipropileno exposta intencionalmente após extração dentária versus técnica de regeneração óssea guiada: ensaio clínico randomizado e cego

Introduction: The intentionally exposed polypropylene (PP) membrane has been proposed for guided bone regeneration (GBR) of the alveo lar bone after extraction; however, there are biological limitations to this proposal. This study aimed to describe the effects of the PP membrane on neo-osteogenesis after tooth extraction, comparing to intentionally ex posed and primary soft tissue coverage techniques. Methodology: This clinical trial followed the TIDieR checklist and guide. Clinical and histo logical parameters of alveolar repair were compared between groups: 1 (control group), without regenerative procedure; 2, GBR; and 3, inten tionally exposed membrane. Results: Group 3 showed slight effect on the quality of new bone, compared to the control group. Although the GBR was underestimated by the early exposure of the membrane, alveo lar repair and newly formed bone were superior to the other groups. Poly propylene membrane intentionally exposed compromised the volume density of the immature and mineralized bone matrix, the osteoblast and osteocyte count, and stimulated the granulation tissue formation and local inflammatory infiltrate. Conclusions: Despite the exposure of the PP membrane in GBR, this technique improved the quality of new bone and alveolar repair compared to the surgical technique of intentional exposure and alveolus only sutured.

RESUMEN Introducción: La membrana de polipropileno (PP) intencionalmente expuesta ha sido propuesta para la regeneración ósea guiada (GBR) del hueso alveolar después de la extracción; sin embargo, existen limitaciones biológicas a esta propuesta. Este estudio tuvo como objetivo describir los efectos de la membrana de PP en la neo-osteogénesis después de la extracción del diente, en comparación con las técnicas de cobertura de tejido blando primarias y expuestas intencionalmente. Metodología: Este ensayo clínico siguió la lista de verificación y la guía TIDieR. Se compararon los parámetros clínicos e histológicos de la reparación alveolar entre los grupos: 1 (grupo control), sin procedimiento regenerativo; 2, GBR; y 3, membrana expuesta intencionalmente. Resultados: el grupo 3 mostró un ligero efecto sobre la calidad del hueso nuevo, en comparación con el grupo de control. Aunque la GBR fue subestimada por la exposición temprana de la membrana, la reparación alveolar y el hueso neoformado fueron superiores a los otros grupos. La membrana de polipropileno expuesta intencionalmente comprometió la densidad de volumen de la matriz ósea inmadura y mineralizada, el recuento de osteoblastos y osteocitos, y estimuló la formación de tejido de granulación y el infiltrado inflamatorio local. Conclusiones: A pesar de la exposición de la membrana de PP en GBR, esta técnica mejoró la calidad del hueso nuevo y la reparación alveolar en comparación con la técnica quirúrgica de exposición intencional y alvéolo solo suturado.

Introdução: A membrana de polipropileno (PP) intencionalmente exposta tem sido proposta para regeneração óssea guiada (ROG) do osso alveolar após exodontia; no entanto, existem limitações biológicas a esta proposta. Este estudo teve como objetivo descrever os efeitos da membrana de PP na neo-osteogênese após a extração dentária, comparando com as técnicas de exposição intencional e cobertura primária de tecidos moles. Metodologia: Este ensaio clínico seguiu a lista de verificação e o guia TIDieR. Parâmetros clínicos e histológicos do reparo alveolar foram comparados entre os grupos: 1 (grupo controle), sem procedimento regenerativo; 2, GBR; e 3, membrana intencionalmente exposta. Resultados: O Grupo 3 apresentou leve efeito na qualidade do novo osso, em comparação com o grupo controle. Embora o GBR tenha sido subestimado pela exposição precoce da membrana, o reparo alveolar e o osso neoformado foram superiores aos outros grupos. A exposição intencional da membrana de polipropileno comprometeu a densidade volumétrica da matriz óssea imatura e mineralizada, a contagem de osteoblastos e osteócitos e estimulou a formação de tecido de granulação e infiltrado inflamatório local. Conclusões: Apesar da exposição da membrana PP na ROG, esta técnica melhorou a qualidade do novo osso e da reparação alveolar em comparação com a técnica cirúrgica de exposição intencional e alvéolo apenas suturado.

ONLAY VERSUS RIVES-STOPPA TECHNIQUES IN THE TREATMENT OF INCISIONAL HERNIAS.

BACKGROUND: In the surgical correction of large incisional hernias, the use of a prosthesis is essential in most cases regardless of the technique chosen. The preference is for the polypropylene prosthesis. AIMS: To compare the onlay and Rives-Stoppa techniques in the correction of incisional hernias, their immediate results, complications, advantages, and disadvantages. METHODS: Two groups of patients with incisional hernias were analyzed, submitted to the onlay (19 patients) and Rives-Stoppa (17 patients) techniques, and that used polypropylene prostheses. General epidemiological variables, perioperative data variables, and postoperative complications were assessed. RESULTS: The patients' epidemiologic profile was similar between both groups. The majority were women (58.4%), with a mean age of 65.5 years and a previous mean body mass index of 41.5 kg/m². The Rives-Stoppa technique was employed in most patients (52.7%). Those submitted to the onlay technique had longer abdominal drainage time and longer hospital stay, as well as a higher incidence of seromas and surgical wound infection. CONCLUSIONS: The incisional herniorrhaphy technique with the placement of a pre-peritoneal polypropylene mesh by the Rives-Stoppa technique was superior to the onlay due to lower rates of drain use, hospital stay, and postoperative complications.

Bilateral inguinal hernia repair and male fertility: a randomized clinical trial comparing Lichtenstein versus laparoscopic transabdominal preperitoneal (TAPP) technique.

BACKGROUND: The effects of hernia repair on testicular function remain uncertain, regardless of the technique used. Studies that analyze testicular volume and flow after hernia repair or hormonal measurements are scarce and show contradictory results. This study aimed to evaluate the impact of bilateral inguinal hernia repair on male fertility in surgical patients in whom the Lichtenstein and laparoscopic transabdominal preperitoneal (TAPP) techniques were used. METHODS: A randomized clinical trial comparing open (Lichtenstein) versus laparoscopic (TAPP) hernia repair using polypropylene mesh was performed in 48 adult patients (20 to 60 years old) with primary bilateral inguinal hernia. Patients were evaluated preoperatively and 90 and 180 postoperative (PO) days. Sex hormones (Testosterone, FSH, LH and SHGB) analysis, testicular ultrasonography, semen quality sexual activity changes and quality of life (QoL) were performed. Postoperative pain was evaluated using the visual analog scale (VAS). RESULTS: Thirty-seven patients with aged of 44 ± 11 years were included, 19 operated on Lichtenstein and 18 operated on TAPP. The surgical time was similar between techniques. The pain was greater in the Lichtenstein group on the 7th PO day. The biochemical and hormonal analyses, testicular ultrasonography (Doppler, testicular volume, and morphological findings) and sperm quality were similar between groups. However, the sperm morphology was better in the Lichtenstein group after 180 days (p < 0.05 vs. preoperative) and two patients who underwent Lichtenstein hernia repair had oligospermia after 180 days. The QoL evaluation showed a significant improvement after surgery in the following domains: physical function, role emotional, bodily pain and general health (p < 0.05). On comparison of Lichtenstein vs. TAPP none of the domains showed statistically significant differences. No patient reported sexual changes. CONCLUSION: Bilateral inguinal hernia repair with polypropylene mesh, whether using Lichtenstein or TAPP, does not impair male fertility in terms of long-term outcomes. TRIAL REGISTRATION: Approved by the Ethics Committee for the Analysis of Research Projects (CAPPesq) of the HC/FMUSP, Number 2.974.457, in June 2015, Registered on Plataforma Brasil in October 2015 under Protocol 45535015.4.0000.0068. Registered on Clinicaltrials.gov, NCT05799742. Enrollment of the first subject in January 2016.

Evaluation and modeling of acrylonitrile migration from polypropylene for food packaging.

This study validated an analytical technique using headspace gas chromatography with flame ionization detection to quantify acrylonitrile monomer with a quantification limit of 0.10 ± 0.04 µg kg-1 . Subsequently, the acrylonitrile migration from polypropylene granules was evaluated in food simulants water and ethanol (50% v/v) and at two temperatures (20 ± 1°C and 44 ± 2°C) for up to 6 weeks, representing the service time of a bottle. From the experimental data obtained, pseudo-second-order kinetics were adjusted to represent the acrylonitrile migration into the simulants. For water, equilibrium concentrations of 13.58 and 16.58 µg kg-1 at 20 and 44°C, respectively, were obtained, while for 50% ethanol, 15.07 and 16.40 µg kg-1 were obtained for the same temperatures. The experimental results and the values estimated from the migration kinetics indicate that the maximum acrylonitrile concentration will not exceed the tolerable specific limit established in regulations. PRACTICAL APPLICATION: The migration of compounds such as acrylonitrile can be a drawback resulting in an undesirable reduction in the shelf life of liquid foods packaged in bottles made of materials such as polypropylene. In this paper, acrylonitrile migration kinetics and a methodology are proposed to determine whether the tolerable migration limits are ever reached, which can serve as a tool for producers of this type of packaging of food to predict shelf life.

Deleterious Effects of Polypropylene Microplastic Ingestion in Nile Tilapia (Oreochromis niloticus).

The effect of daily ingestion of polypropylene microplastic on the health of tilapia, Oreochromis niloticus, was evaluated. 60 fish (± 200 g) were placed in 6 aquariums (n = 10, 100 L each), constituting the following treatments: Control (without the addition of polymer), fed with 100 and 500 µg of polypropylene/kg of body weight (b.w.), respectively. After 30 days of feeding, the animals were submitted to blood collection for hemogram and biochemical study and later euthanized for gut microbiological analysis, somatic index of liver, spleen, heart, kidney, stomach, and intestine. In the serum biochemical study, an increase in cholesterol and serum Aspartate Aminotransferase (AST) activity levels was observed in animals treated with 500 µg of polypropylene. Tilapia-fed polypropylene in the diet showed an increase in thrombocyte and total leukocyte counts, marked by a significant increase in the number of circulating lymphocytes. The results of the somatic study revealed a significant increase in the stomach, liver, and heart of tilapia fed with the polymer. Increase in the number of Gram-negative microorganisms and decrease in mesophilic aerobic microorganisms were observed in the gut of fish exposed to the polymer, including a dose-response effect was observed for these analyses. Therefore, tilapias fed daily with diets containing polypropylene for 30 consecutive days showed deleterious effects, resulting in systemic inflammatory disturbs by altering liver functions, leukocyte profile, and organ morphometry, as well as changes in the intestinal microbiota. Such results demonstrate the impairment of fish health, highlighting the need for further studies that evaluate the impact of microplastics on aquatic organisms.

Identifying, Quantifying, and Recovering a Sorbitol-Type Petrochemical Additive in Industrial Wastewater and Its Subsequent Application in a Polymeric Matrix as a Nucleating Agent.

Currently, polypropylene (PP) is highlighted using sorbitol-based clarifying agents since these agents are high quality, low cost, and work as a barrier against moisture, which makes PP ideal for packaging food, beverages, and medical products, among others. The use of analytical methods capable of recovering these additives in wastewater streams and then reusing them in the PP clarification stage represents an innovative methodology that makes a substantial contribution to the circular economy of the PP production industry. In this study, a method of extraction and recovery of the Millad NX 8000 was developed. The additive was recovered using GC-MS and extracted with an activated carbon column plus glass fiber, using an injection molded sample, obtaining a recovery rate greater than 96%. TGA, DSC, and FTIR were used to evaluate the recovered additive's glass transitions and purity. The thermal degradation of the recovered additive was found to be between 340 and 420 °C, with a melting temperature of 246 °C, adopting the same behavior as the pure additive. In FTIR, the characteristic absorption peak of Millad NX 8000 was observed at 1073 cm-1, which indicates the purity of the extracted compound. Therefore, this work develops a new additive recovery methodology with high purity to regulate the crystallization behavior and of PP.

Framework for data-driven polymer characterization from infrared spectra.

Automating infrared spectra interpretation in microplastic identification is of interest since most current methodologies are conducted manually or semi-automatically, which requires substantial processing time and presents a higher accuracy limited to single-polymer materials. Furthermore, when it comes to multicomponent or weathered polymeric materials commonly found in aquatic environments, identification usually becomes considerably depreciated as peaks shift and new signals are frequently observed, representing a significant deviation from reference spectral signatures. Therefore, this study aimed to develop a reference modeling framework for polymer identification through infrared spectra processing, addressing the limitations above. The case study selected for model development was polypropylene (PP) identification, as it is the second most abundant material in microplastics. Therefore, the database comprises 579 spectra with 52.3% containing PP to some degree. Different pretreatment and model parameters were evaluated for a more robust investigation, totaling 308 models, including multilayer perceptron and long-short-term memory architectures. The best model presented a test accuracy of 94.8% within the cross-validation standard deviation interval. Overall, the results achieved in this study indicate an opportunity to investigate the identification of other polymers following the same framework.