Contaminación ambiental por plásticos durante la pandemia y sus efectos en la salud humana / Environmental pollution by plastics during the pandemic and its effectson human health

La historia del plástico se remonta a mediados del siglo XIX, y se considera que se origina por el interés de cambiar la materia prima en la fabricación de las bolas de billar, hechas originalmente en marfil. Desde entonces y a lo largo de muchos años, el polietileno, cloruro de polivinilo, poliestireno, polimetilmetacrilato, polietilentereftalato (PET), las poliamidas y otras sustancias similares han formado parte del día a día de la humanidad, a tal punto que algunos expertos en el tema consideran que estamos viviendo "La era del plástico". Todos los insumos y elementos plásticos han facilitado la vida, pero también han causado una gran contaminación ambiental que afecta la fauna, la flora y por supuesto al ser humano. La gran mayoría de los países han comprendido esta situación y han promulgado leyes o diseñado estrategias con el fin de contener el uso inadecuado y la generación de la contaminación causada por el plástico. Muchas de estas medidas han sido frenadas e incluso revertidas debido a la pandemia por COVID-19, que además de todas las afectaciones conocidas, ha causado un desmesurado incremento en el uso de materiales plásticos, como los elementos de protección personal, con el consecuente aumento de la contaminación y los riesgos que esta genera en la salud humana. Estos temas son tratados en este artículo, con el fin de concientizar al personal médico y a la población en general

The history of plastic dates back to the mid-nineteenth century, and it is considered that it originates from the interest in changing the raw material in the manufacture of billiard balls, originally made of ivory. Since then and for many years, polyethylene, polyvinyl chloride, polystyrene, polymethyl methacrylate, polyethylene terephthalate (PET), polyamides and other similar substances have been part of humanity's daily life, to the point that some consider that we are living 'The era of plastic'.All the inputs and plastic elements have made life easier, but they have also caused great environmental pollution that affects fauna and flora, and of course the human being. The vast majority of countries have understood this situation, have enacted laws and designed strategies in order to contain the inappropriate use and generation of pollution caused by plastic.Many of these measures have been stopped and even reversed due to the COVID-19 pandemic, which in addition to all the known effects, has caused a disproportionate increase in the use of plastic materials, such as personal protection elements with the consequent increase in pollution and the risks it generates for human health. These issues are addressed in this article, in order to raise awareness among medical personnel and the general population

Clinical observation on plastic splint treatment of middle clavicle fracture based on a new classification / 中国骨伤

OBJECTIVE@#According to 73 patients with middle clavicle fracture treated conservatively, a new classification of middle clavicle fracture was proposed, and the clinical effect of plastic splint in the treatment of middle clavicle fracture was observed.@*METHODS@#Total 73 patients with middle clavicle fracture treated with plastic splint from September 2018 to August 2020 were analyzed retrospectively. All the patients were divided into 4 types according to the degree of fracture displacement. There were 16 cases of typeⅠ, including 7 males and 9 females, ranging in age from 18 to 37 years old, with a mean of (28.6±7.8) years old;12 cases of mild disease, 3 cases of moderate disease and 1 case of severe disease. There were 16 cases of type Ⅱ, including 6 males and 10 females, ranging in age from 25 to 49 years old, with a mean of (37.3±9.4) years old;5 cases of mild disease, 8 cases of moderate disease and 3 cases of severe disease. There were 7 cases of type Ⅲ, including 4 males and 3 females, ranging in age from 33 to 57 years old;2 cases of mild disease, 3 cases of moderate disease and 2 cases of severe disease. There were 34 cases of type Ⅳ, including 16 males and 18 females, ranging in age from 48 to 82 years old, with a mean of(66.4±14.9) years old;7 cases of mild disease, 17 cases of moderate disease and 10 cases of severe disease. All patients received plastic splint external fixation for 4 weeks. Visual analgue scale (VAS) and Constant-Murley shoulder scores before treatment and 1, 3 and 9 months after treatment were observed and recorded to evaluate the change of pain degree and shoulder function recovery before and after treatment. The patients' satisfaction with the appearance after treatment was recorded at the latest follow-up. The X-ray findings at the latest follow-up were used to judge whether the patient had fracture nonunion. And according to the fracture healing time and imaging findings, the excellent and good rate of clinical curative effect in patients with different types was obtained.@*RESULTS@#All patients were followed up, and the duration ranged from 9 to 11 months, with a mean of (9.8±0.7) months. The VAS scores of typeⅠ, typeⅡand type Ⅳ before treatment were 2.88±0.83, 3.67±0.80 and 6.92±1.71 respectively, which were decreased to 0.54±0.19, 0.77±0.25 and 1.18±0.17 respectively after 9 months of treatment. The Constant-Murley shoulder scores of typeⅠ, typeⅡand type Ⅳ were 65.81±2.09, 63.50±2.22 and 47.93±2.91 respectively before treatment, and increased to 88.56±2.11, 85.12±2.23 and 71.25±2.16 respectively after 9 months of treatment. Five patients were not satisfied with the appearance after treatment;6 patients had no obvious continuous callus passing through after 9 months of treatment, which was fracture nonunion.@*CONCLUSION@#The classification of middle clavicle fracture is more appropriate to the clinic, which has a certain clinical guiding significance for the selection of treatment methods and prognosis of middle clavicle fracture. Plastic splint is effective in the treatment of middle clavicle fracture without obvious displacement and overlapping displacement, and the incidence of complications is low. It can be popularized in clinic.

Overlap esophagojejunostomy with multi-mode modifications in totally laparoscopic total gastrectomy: safety and feasibility of 152 cases from a single center / 中华胃肠外科杂志

Objective: Currently, the Overlap anastomosis is one of the most favored reconstruction methods of intracorporeal esophagojejunostomy (EJS). Despite many advantages of the method, it remains some shortcomings to be improved when it comes to the retraction of the esophagus stump, the insertion of the anvil fork of the linear stapler into a "pseudo" lumen, and the closure of the common entry hole. This study aims to investigate the safety and feasibility of a multi-mode modified Overlap anastomosis. Methods: A descriptive case series study was conducted. Medical records of 152 consecutive patients who underwent totally laparoscopic total gastrectomy (TLTG) with our multi-mode modified Overlap EJS method by the same surgical team at our department from February 2017 to June 2020 were retrospectively analyzed. The multi-mode modified Overlap method mainly included (1) After ensuring the safety of tumor resection margin (proximal margin was at least 3 cm from the tumor), the esophagus was partially transected from left to right (with 5-8 mm width esophagus continuation). The specimen was then placed in a plastic bag which was tied up at the mouth using strings with a part of the esophageal wall poking through. Then the plastic bag containing the specimen was transferred to the right lumbar region, while the patient's body position was adjusted so that the abdominal esophagus could be pulled by the gravity of the specimen. (2) Using the "three-direction traction" method. The esophageal lumen was properly exposed, then guided by the gastric tube, the anvil fork was accurately placed into the esophageal lumen for completing the side-to-side EJS. (3) The 3-0 barbed suture was used in the closure of the common entry hole of the stapler from dorsally to ventrally with simple one-layer continuous suture (the stitch going from inside to inside) followed by continuous Lembert's suture (the stitch going from outside to outside). Combined with clinicopathological characteristics, the perioperative outcomes and postoperative complications of the whole group were analyzed and evaluated. Results: The study cohort included 129 men and 23 women, with a mean age of (60.2±9.1) years and a mean body mass index (BMI) of (23.2±3.1) kg/m(2). Of the 152 patients, 23 patients (15.1%) had a history of previous abdominal surgery; dentate line was invaded by tumor in 21 patients (13.8%). The mean length of the proximal resection margin was (3.3±0.3) cm and the postoperative pathological examination indicated negative resection margin tumor. The mean operative time and anastomotic time were (302.1±39.9) minutes and (29.8±5.4) minutes, respectively. The mean estimated blood loss was (87.9±46.4) ml. The mean length of postoperative hospital stay was (12.3±7.3) days. The overall severe postoperative complications (Clavien-Dindo ≥ II) occurred in 22 patients (14.5%). Six cases of pancreatic leakage were successfully recovered by adequate drainage, inhibition of pancreatic exocrine secretion and nutritional support. Ten cases of pneumonia and three cases of abdominal infection were cured with anti-infection and physical therapy. Two patients developed anastomotic leakage postoperatively. One case was caused by excessive tension of the Roux loop of the jejunum and excessive opening on the side of the jejunum after side-to-side anastomosis, and the other case was caused by an accidental intraoperative occurrence of "nasogastric tube stapled to the side-to-side anastomosis". Both of them recovered after conservative treatment including adequate drainage, anti-infection, and adequate nutritional support. One patient underwent immediate open surgery because of Peterson's hernia 7 days after TLTG, and the patient died due to extensive small bowel necrosis. Conclusions: Multi-mode modified overlap method simplifies the operation and reduces the difficulty of EJS. It is a safe and feasible method for EJS.

Saneamiento industrial: Biodisponibilidad de patógenos en superficies / Industrial sanitation: Bioavailability of pathogens on surfaces

En condiciones adecuadas como humedad, alcalinidad, o temperatura, determinados patógenos logran adherirse a las superficies y sobrevivir ciertos períodos fuera de un anfitrión, persistiendo en algunos casos a procesos deficientes de limpieza y desinfección, configurándose como un posible foco de transmisión. Por ello, el correcto saneamiento cumple un propósito vital en la protección de los trabajadores de la industria y otros sectores frente al riesgo de contaminación por contacto directo con las superficies contaminadas. La literatura científica muestra amplia evidencia de la supervivencia de patógenos sobre superficies que son habituales dentro de instalaciones industriales, como acero, aluminio, madera, plástico y vidrio. La supervivencia de microorganismos en las superficies puede configurarse como candidato a marcador de biodisponibilidad, que puede ser usado en la industria para establecer y auditar los planes de higienización y saneamiento industrial, permitiendo estudiar la eficacia de los compuestos usados en la desinfección, y variables como su concentración, temperatura, e intervalos de aplicación y remoción(AU)

Under suitable conditions such as humidity, alkalinity, or temperature, certain pathogens manage to adhere to surfaces and survive certain periods outside of a host, persisting in some cases to poor cleaning and disinfection processes, becoming a possible source of transmission. Therefore, proper sanitation serves a vital purpose in protecting workers in industry and other sectors from the risk of contamination by direct contact with contaminated surfaces. The scientific literature shows ample evidence of the survival of pathogens on surfaces that are common within industrial facilities, such as steel, aluminum, wood, plastic and glass. The survival of microorganisms on surfaces can be configured as a candidate for bioavailability marker, which can be used in the industry to establish and audit industrial sanitation and sanitation plans, allowing to study the efficacy of the compounds used in disinfection, and variables such as its concentration, temperature, and application and removal intervals(AU(

Higienización y eliminación fúngica en instalaciones industriales para la disminución de riesgos ocupacionales / Sanitization and fungal elimination in industrial facilities to reduce occupational risks

Se ha comprobado que la exposición a bioaerosoles se asocia con varios efectos sobre la salud, como enfermedades pulmonares y alergias. El presente estudio transversal tuvo como objetivo investigar la contaminación por hongos en varias superficies pertenecientes a dos industrias de alimentos. La toma de muestra se realizó en tres semanas, inmediatamente después de realizada la limpieza y desinfección y antes de iniciar la producción. Se recolectaron 400 muestras de superficie (vidrio, acero inoxidable, aluminio, goma y plástico), también se evaluó la eficacia del programa de higienización en el control de la población de hongos. Todas las muestras presentaron recuentos fúngicos <10 ufc/cm2, sin haber diferencias significativas entre los tipos de superficie, sin embargo, las superficies plásticas exhibieron mayor crecimiento logarítmico de los hongos. Se determinó que 49,60% de las especies identificadas correspondieron al género Penicillium. Aunque los niveles de hongos en las industrias estudiadas fueron inferiores a los niveles recomendados por la Organización Mundial de la Salud, algunas medidas de salud ambiental como lavar y desinfectar las superficies después de cada turno de trabajo, y se recomiendan inspecciones periódicas para garantizar la seguridad de los trabajadores y de los productos que allí se manufacturan(AU)

It has been proven that exposure to bioaerosols is associated with several health effects, such as pulmonary diseases and allergies. The present crosssectional study aimed to investigate fungal contamination on various surfaces belonging to two food industries. The sampling was carried out in three weeks, immediately after cleaning and disinfection and before starting production. 400 surface samples were collected (glass, stainless steel, aluminum, rubber and plastic), the effectiveness of the sanitation program in controlling the fungal population was also evaluated. All the samples presented fungal counts <10 cfu / cm2, with no significant differences between the types of surfaces, however, the plastic surfaces exhibited higher logarithmic growth of the fungi. It was determined that 49.60% of the identified species corresponded to the Penicillium genus.Although the levels of fungi in the studied baths were lower than the levels recommended by the World Health Organization, some environmental health measure ssuch as washing and disinfecting surfaces after each working shift and periodic inspections are recommended ensuring the safety of the workers and the products that are manufactured there(AU)

Levels of BPA in makdous, a traditional Syrian food, using solid-phase extraction followed by HPLC

Bisphenol A (BPA), an endocrine disrupter, can migrate from packaging material into food stuff. This research was designed to measure BPA levels in makdous, a traditional Syrian food. Forty three samples of makdous stored in different plastic containers (polyethylene (PE), polypropylene (PP), and unspecified plastic containers) were analyzed every 3 months for one year beginning July 2017. Quantification of BPA was carried out by an RP-HPLC system equipped with fluorescence detector after solid phase extraction. Migration was found in PE and PP plastic containers with slight differences. Statistically significant differences in BPA levels were observed between samples assayed after two weeks of preparation and samples assayed after 12 months (mean 16.32 vs. 38.26 µg/kg, p value=0.003). According to these amounts, BPA levels were all under the specific migration limit of 0.05 mg/kg as newly referred in Regulation (EU) No 2018/213. These levels of exposure would only contribute to 2.15% and 2.75% of the EFSA t-TDI in both men and women respectively based on mean dietary exposure estimates derived from a 24-h dietary information study from 875 participants. Hence there are no concerns about potential health risks from makdous consumption

Efficacy and safety of endoscopic ultrasound-guided drainage of pancreatic pseudocysts using double-pigtail plastic stents: A single tertiary center experience

OBJECTIVES: Pancreatic pseudocysts (PPC) are fluid collections with a well-defined wall that persist for more than 4 weeks inside or around the pancreas as a result of pancreatic inflammation and/or a ductal lesion. PPC have been successfully treated with endoscopic ultrasound (EUS)-guided drainage using different stents. This study aimed to evaluate the safety and efficacy of EUS-guided drainage of PPC using double-pigtail plastic stents in a tertiary hospital. METHODS: Patients with PPC referred for EUS-guided drainage between May 2015 and December 2019 were included in this case series. The primary endpoint was to evaluate the efficacy (clinical success) and safety (adverse events and mortality) of EUS-guided drainage of PPC. Secondary endpoints included technical success and pseudocyst recurrence. RESULTS: Eleven patients (mean age, 44.5±18.98 years) were included in this study. The etiologies for PPC were acute biliary pancreatitis, chronic alcoholic pancreatitis, and blunt abdominal trauma. The mean pseudocyst size was 9.4±2.69 cm. The clinical success rate was 91% (10/11). Adverse events occurred in three of 11 patients (27%). There were no cases of mortality. The technical success rate was 100%. Pseudocyst recurrence was identified in one of 11 patients (9%) at 12 weeks after successful clinical drainage and complete pseudocyst resolution. CONCLUSION: EUS-guided transmural drainage of PPC using double-pigtail plastic stents is safe and effective with high technical and clinical success rates.

BPA toxicity during development of zebrafish embryo / Toxicidade do BPA durante o desenvolvimento de embriões de Zebrafish

Bisphenol A (BPA) is a monomer used in the production of polycarbonate, a polymer commonly found in plastics, epoxy resins and thermal papers. The presence of BPA in food, water, air and dust has been of great concern in recent years not only due to environmental and ecological issues but also because of its supposed risk to public health related to its mutagenic and carcinogenic potential. In this study we evaluated the toxicity of bisphenol A in zebrafish embryos (Danio rerio) and determined the 50% lethal concentration (LC50) of this chemical. BPA was used at concentrations ranging from 1 µM to 100 µM in E3 medium/0.5% dimethylsulfoxide (DMSO) from previously prepared stock solutions in 100% DMSO. Controls included embryos exposed only to E3 medium or supplemented with 0.5% DMSO. Camptothecin (CPT), a known inhibitor of cell proliferation was used as positive control at a concentration of 0.001 µM in E3 medium/0.5% DMSO. Adults zebrafish were placed for breeding a day before the experimental set up, then, viable embryos were collected and selected for use. Experiments were carried out in triplicates, according to specifications from Organization for Economic Cooperation and Development (OECD). One embryo/well (25 embryos per concentration) was distributed in 96 well microplates in presence or absence of the chemicals. The plates were kept in BOD incubators with a controlled temperature of 28.5 ºC and with photoperiod of 14 h light:10 h dark. After 24h, 48h, 72h and 96h exposure, the exposed embryos were evaluated according to the following parameters: mortality, coagulation, rate of heartbeat, hatching and presence of morphological abnormalities. Photography was obtained by photomicroscopy. Apoptosis was evaluated by DNA ladder assay. DNA was extracted by phenol:chloroform method and analyzed by 2% agarose gel electrophoresis. DNA fragments were visualized after ethidium bromide staining in ultraviolet transilluminator. The LC50 determined for BPA was 70 µM after 24 hours, 72 µM after 48 hours, 47 µM after 72 hours and 31 µM after 96 hours exposure. BPA induced morphological and physiological alterations such as yolk sac and pericardial edema, hatching delay or inhibition, spine deformation, decreasing in heartbeat rate and mortality. In conclusion, this study demonstrated that BPA induced marked malformations in zebrafish embryos at concentrations above 25 µM corroborating the current concerns related to the widespread presence of BPA in the air, food and water used by humans as well as in the bodily fluids and tissues.

Bisfenol A (BPA) é um monômero utilizado na produção de policarbonato, um polímero comumente encontrado em plásticos, resinas epóxi e papéis térmicos. A presença de BPA em alimentos, água, ar e poeira tem sido motivo de grande preocupação nos últimos anos, não só devido a questões ambientais e ecológicas, mas também ao suposto risco para a saúde pública relacionado ao seu potencial mutagênico e carcinogênico. Neste estudo avaliamos a toxicidade do bisfenol A em embriões de peixe-zebra (Danio rerio) e determinamos a concentração letal 50% (LC50) deste composto químico. O BPA foi usado na faixa de concentração entre 1 µM e 100µM em meio E3/0,5% de dimetilsulfóxido (DMSO), preparado a partir de soluções estoques em 100% DMSO. Os controles negativos incluíram embriões expostos apenas ao meio E3 ou suplementado com 0,5% DMSO. Camptotecina (CPT), um conhecido inibidor da proliferação celular, foi usado como controle positivo a uma concentração de 0,001 µM em meio E3/0,5% DMSO. Peixes-zebra adultos foram colocados para reprodução um dia antes da montagem experimental, em seguida, embriões viáveis foram coletados e selecionados para uso. Os experimentos foram realizados em triplicata, de acordo com as especificações da Organização para Cooperação e Desenvolvimento Econômico (OCDE). Um embrião/ poço (25 embriões por concentração) foi distribuído em microplacas de 96 poços na presença ou ausência dos compostos químicos. As placas foram mantidas em incubadoras BOD com temperatura controlada de 28,5 ºC e com fotoperíodo de 14h claro:10h escuro. Após 24h, 48h, 72h e 96h, os embriões expostos foram avaliados de acordo com os seguintes parâmetros: mortalidade, presença de coagulação, taxa do batimento cardíaco, eclosão e presença de anormalidades morfológicas. Fotografias foram obtidas por fotomicroscopia. A apoptose foi avaliada pelo ensaio de DNA ladder. O DNA foi extraído pelo método fenol:clorofórmio e analisado por eletroforese em gel de agarose a 2%. Fragmentos de DNA foram visualizadas após coloração com brometo de etídio em um transiluminador ultravioleta. A LC50 determinada para o BPA foi 70 µM após 24 horas, 72 µM após 48 horas, 47 µM após 72 horas e 31 µM após exposição por 96 horas. O BPA induziu alterações morfológicas e fisiológicas como edema de saco vitelino e edema pericárdico, atraso no tempo ou inibição da eclosão, deformação da coluna vertebral, diminuição da taxa de batimentos cardíacos e mortalidade. Em conclusão, este estudo demonstrou que o BPA induziu grande número de malformações em embriões de peixe-zebra em concentrações acima de 25 µM, corroborando as preocupações atuais relacionadas a presença generalizada do BPA no ar, alimento e água usados pelos seres humanos bem como nos fluidos e tecidos corporais.

Degradation of petroleum-based plastics by microbes and microbial consortia / 生物工程学报

Along with the increasingly serious environmental pollution, dealing with the "white pollution" issue, which is caused by the worldwide use of not readily-degradable or non-degradable synthetic plastics, has become a great challenge. It is an environmentally friendly strategy to degrade synthetic plastics using microorganisms that exist in nature or evolved under selection pressure. Based on the NSFC-EU International Cooperation and Exchanges Project "Bio Innovation of a Circular Economy for Plastics", this review summarized the screening of bacteria, fungi and microbial consortia capable of degrading synthetic plastics such as polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyurethane (PUR), and polyethylene terephthalate (PET). We also analyzed the role of various microorganisms played in the degradation of petroleum-based plastics. Moreover, we discussed the pros and cons of using microorganisms and enzymes for degradation of synthetic plastics.

MIXed plastics biodegradation and UPcycling using microbial communities: the NSFC-EU 2019 project MIX-UP to help achieve "carbon neutrality" / 生物工程学报

With the transformation and revolution of the global plastics recycling system, recycling and upcycling of mixed plastics waste not only reduces the carbon emissions of plastics during its life cycle, but also addresses its potential ecological and environmental hazards. This article summarizes an international cooperation project, "MIXed plastics biodegradation and UPcycling using microbial communities" (MIX-UP) which was funded by the National Natural Science Foundation of China and the European Union (NSFC-EU) in 2019. The consortium of MIX-UP consists of 14 partners from European Union and China. Focusing on the global issue of "plastics pollution", this Sino-European MIX-UP project took the mixed waste of petroleum-based plastics (PP, PE, PUR, PET and PS) and bio-based plastics (PLA and PHA) as starting materials for biotechnological conversion into value-added, sustainable biomaterials. MIX-UP has three subprojects: 1) identification of plastics biodegradation pathway and design & engineering of key degrading elements, 2) construction and functional regulation of microbial consortia/enzyme cocktails with high-efficiency for degradation of plastics mixtures, 3) strategy of design and utilization of plastics degradation products for production of high value materials. Through NSFC-EU complementary and cross-disciplinary cooperation, MIX-UP proposes the engineering of a new-to-nature biological route for upcycling, a low carbon and sustainable bio-treatment that is different from the traditional physico-chemical treatment, which will empower the recycling industry to a new dimension. The implementation of the project will not only help to promote innovation and development in the field of biotechnology in China, but also contribute to the achievement of China's carbon neutral goal.

Plastics biodegradation and recycling - the introduction of China-Europe cooperation project "Synthetic microorganism communities for plastic degradation and transformation" / 生物工程学报

The China-European environmental biotechnology cooperation research project on the biodegradation of waste plastics is jointly funded by the National Natural Science Foundation of China (NSFC) and the European Commission (EC), and aims to encourage Chinese and European scientists to carry out substantive research in the field of "Microorganism communities for plastics biodegradation". The goal of the project is to use the metabolic capacity of microbial communities to degrade petrochemical plastics that are easy to cause environmental pollution into monomers and small molecules, thereby realizing the biosynthesis of high-value biochemicals by microorganisms. This can not only solve the problem of plastic pollution, but also "turn waste into treasure" and create higher economic benefits. The China-European cooperative research project will promote in-depth cooperation between scientists from both sides in the field of synthetic biology, and help the two sides establish long-term and stable international exchanges and cooperation. Both China and the EU will work to solve the global plastic pollution problem, form a strategic force of science and technology, and jointly open a new chapter in the field of resource utilization of non-degradable plastics.

Environmental scientists & microbiologists from China & EU: take the responsibility to cherish the Earth homeland / 生物工程学报

Humanity shares the common interest to protect the environment and to maintain a healthy global ecosystem. International collaboration is key in this context, to advance the necessary science and technology. The National Science Foundation of China (NSFC) and European Commission (EC) have agreed to collaborate in innovative knowledge and technology in the field of bioremediation of polluted environments and biodegradation of plastics. In this context, projects on bioremediation of soils, wastewater and sediment matrices and on microbial degradation of plastics were supported. This special issue aimed to introduce these projects and their progresses in the related fields. In total, 23 papers have been collected in this issue, covering both fundamental and applied researches.

Advances in microbial degradation of plastics / 生物工程学报

Plastics are widely used in daily life. Due to poor management and disposal, about 80% of plastic wastes were buried in landfills and eventually became land and ocean waste, causing serious environmental pollution. Recycling plastics is a desirable approach, but not applicable for most of the plastic waste. Microbial degradation offers an environmentally friendly way to degrade the plastic wastes, and this review summarizes the potential microbes, enzymes, and the underpinning mechanisms for degrading six most commonly used plastics including polyethylene terephthalate, polyethylene, polyvinyl chloride, polypropylene, polystyrene and polyurethane. The challenges and future perspectives on microbial degradation of plastics were proposed.

Engineering progress in microbial production of polyhydroxyalkanoates / 生物工程学报

Polyhydroxyalkanoates (PHAs) are polymers obtained by esterification of hydroxy fatty acid monomers. Due to similar mechanical characteristics of traditional petroleum-based plastics, 100% biodegradability and biocompatibility, PHAs are considered to be one of the most potential green materials. However, the application and promotion of PHAs as a green and environmentally friendly material are difficult because of the high production costs. This article focuses on the current methods to reduce production cost of PHAs effectively, such as cell morphology regulation, metabolic pathway construction, economic carbon source utilization and open fermentation technology development. Despite most research results are still limited in laboratory, the research methods and directions provide theoretical guidance for the industrial production of economic PHAs.

Suicidio por confinamiento con bolsa plástica y gas helio: presentación de dos casos / Suicide with plastic bag and helium gas: two case report

Resumen El confinamiento al igual que el sepultamiento son parte de las sofocaciones por carencia de aire respirable. Su etiología principal es la accidental, como ocurre con los mineros o los niños que juegan con bolsas de plástico o quedan atrapados dentro de lugares sin ventilación. En la actualidad se ha visto el aumento a nivel mundial sobre todo en países desarrollados, del uso de una bolsa plástica en conjunto con algún gas noble (principalmente helio) como método suicida "per se" o como proceso final de eutanasia. En el presente artículo se hará revisión de dos casos en Costa Rica, con sus hallazgos en la necropsia, la carencia de hallazgos toxicológicos y la importancia del escenario de muerte para poder emitir un criterio desde el punto de vista médico legal.

Abstract The confinement as well as the burial are part of the suffocations due to lack of breathable air. Its main etiology is accidental, as it happens with miners or the children who play with plastic bags or get trapped inside unventilated places. At present, the increase in the world has been seen especially in developed countries of the use of a plastic bag in conjunction with some noble gas (mainly helium) as a suicidal method or as a final process of euthanasia.

Diseño innovador para la obtención y caracterización de un bioplástico utilizando como materia base la fibra de la cáscara de coco y papaya / Innovative design for obtaining and characterizing a bioplastic using as a base material the fiber of the coconut shell and papaya fiber

Los plásticos se producen a partir del petróleo. Estos polímeros perduran en la naturaleza por largos períodos de tiempo y, por tanto, se acumulan, generando así grandes cantidades de residuos sólidos. El objetivo principal de esta investigación es producir, a escala de laboratorio, un bioplástico a partir de la fibra contenida en la cáscara de coco, que pueda servir de materia prima para la elaboración de productos biodegradables.

Plastics are produced from oil. These polymers persist in nature for long periods of time and, therefore, they are accumulated in large amounts of solid waste. The main objective of this research is to produce, on a laboratory scale, a bioplastic from the fiber contained in the coconut shell, which can serve as raw material for the production of biodegradable products.

Papel de distintas técnicas de imagen para identificar y localizar cuerpos extraños intraoculares relacionados con trauma ocular abierto: reporte de tres casos y revisión de la literatura / The role of various imaging techniques in identifying and locating intraocular foreign bodies related to open-globe injury: three case reports and literature review

ANTECEDENTES La ubicación precisa de un cuerpo extraño intraocular es crucial para el manejo de pacientes con trauma ocular abierto. La tomografía computarizada se usa habitualmente para detectar su ubicación en el segmento posterior. Reportamos tres casos con diferentes cuerpos extraños intraoculares en el segmento posterior, que fueron localizados con precisión mediante la tomografía computarizada y ecografía modo B. PRESENTACIÖN DEL CASO Presentamos tres casos con diferentes mecanismos de trauma, tipos de cuerpo extraño intraocular, síntomas clínicos y pronóstico visual. La tomografía computarizada determinó la ubicación exacta de todos los cuerpos extraños intraoculares en el segmento posterior. El ultrasonido modo B se realizó en un paciente con un cuerpo extraño intraocular no metálico. El primer caso tuvo una lesión ocular perforante con un cuerpo extraño intraorbitario; el caso dos y el caso tres presentaron diferentes tipos de cuerpos extraños intraoculares con pronóstico diferente. El manejo y el pronóstico fue distinto en todos los casos; todos se manejaron con éxito. La ubicación exacta de los cuerpos extraños intraoculares utilizando las diferentes modalidades de diagnóstico es importante en estos pacientes. Estos casos sirven como recordatorio de que el uso adecuado de las pruebas de imagen es indispensable en el contexto de un cuerpo extraño intraocular relacionado con trauma ocular abierto. CONCLUSIÓN Las diferentes técnicas de imágenes son muy importantes para la detección de un cuerpo extraño intraocular. La tomografía computarizada es una de las modalidades de imagen más simple y efectiva para la localización de cuerpos extraños intraoculares relacionadas con trauma ocular abierto.

BACKGROUND: Determining the precise location of intraocular foreign bodies is crucial for the management of patients with open-globe injury. Computed tomography is the most common method for detecting intraocular foreign bodies in the posterior segment. In this article, we describe three cases of open-globe injury with different types of intraocular foreign bodies in the posterior segment that were accurately located using computed tomography scans and B-scan ultrasonography. CASE PRESENTATION: Each of the three cases of open-globe injury described in this report had different types of ocular trauma, clinical symptoms, and intraocular foreign bodies. Computed tomography scans showed the exact location of the intraocular foreign bodies in the posterior segment in two of the three cases. A B-scan ultrasound was used to determine the location of a non-metallic intraocular foreign body in the third case. All three patients had intraocular foreign bodies, and one of them had an additional orbital foreign body. Case 1 had a perforating eye injury with the additional intraorbital foreign body; Cases 2 and Case 3 had different types of intraocular foreign bodies and prognoses. Various treatment approaches were used, ranging from observation to surgery, depending on the location of the intraocular foreign bodies, and all cases were successfully managed. These three cases show that proper use of various types of imaging tests is indispensable in the context of an intraocular foreign body related to open-globe injury. CONCLUSION: Imaging techniques are crucial for the detection of an intraocular foreign body, and computed tomography is one of the simplest and most useful, especially in cases of open-globe injury.

Effectiveness of Two Types of Photostimulable Phosphor Plate Plastic Barrier Envelopes for Prevention of Microbiological Contamination

Abstract Objective: To compare the effectiveness of two types of commercially available photostimulable phosphor plate (PSP) protective barrier envelopes to prevent microbiological contamination. Material and Methods: In this cross-sectional study, 80 barrier envelopes were tested in 40 volunteers. The PSP plates were placed individually in Asia Teb and Soredex protective barrier envelopes and were placed in the mouth for two minutes, similar to periapical films. The protective barrier envelopes were then removed under sterile conditions, and the sensors were placed on different culture media. The number of colonies on each plate was counted. Data were analyzed using SPSS via McNemar and Wilcoxon tests. Results: Bacterial growth was noted in 17.5% of PSPs with Soredex, and 32.5% of PSPs with Asia Teb barrier envelopes. Gram-positive bacilli were the most commonly isolated bacteria. The difference between the Asia Teb and Soredex barrier envelopes for the protection of microbiological contamination was not significant (p>0.05). Conclusion: The use of different types of protective barrier envelopes was not sufficient for prevention of microbiological contamination of PSP plates, and some adjunct modalities were required to decrease microbiological contamination of PSP plates.

Heterogeneity of Human γδ T Cells and Their Role in Cancer Immunity

The γδ T cells are unconventional lymphocytes that function in both innate and adaptive immune responses against various intracellular and infectious stresses. The γδ T cells can be exploited as cancer-killing effector cells since γδ TCRs recognize MHC-like molecules and growth factor receptors that are upregulated in cancer cells, and γδ T cells can differentiate into cytotoxic effector cells. However, γδ T cells may also promote tumor progression by secreting IL-17 or other cytokines. Therefore, it is essential to understand how the differentiation and homeostasis of γδ T cells are regulated and whether distinct γδ T cell subsets have different functions. Human γδ T cells are classified into Vδ2 and non-Vδ2 γδ T cells. The majority of Vδ2 γδ T cells are Vγ9δ2 T cells that recognize pyrophosphorylated isoprenoids generated by the dysregulated mevalonate pathway. In contrast, Vδ1 T cells expand from initially diverse TCR repertoire in patients with infectious diseases and cancers. The ligands of Vδ1 T cells are diverse and include the growth factor receptors such as endothelial protein C receptor. Both Vδ1 and Vδ2 γδ T cells are implicated to have immunotherapeutic potentials for cancers, but the detailed elucidation of the distinct characteristics of 2 populations will be required to enhance the immunotherapeutic potential of γδ T cells. Here, we summarize recent progress regarding cancer immunology of human γδ T cells, including their development, heterogeneity, and plasticity, the putative mechanisms underlying ligand recognition and activation, and their dual effects on tumor progression in the tumor microenvironment.

Innate Lymphoid Cells in the Airways: Their Functions and Regulators

Since the airways are constantly exposed to various pathogens and foreign antigens, various kinds of cells in the airways—including structural cells and immune cells—interact to form a precise defense system against pathogens and antigens that involve both innate immunity and acquired immunity. Accumulating evidence suggests that innate lymphoid cells (ILCs) play critical roles in the maintenance of tissue homeostasis, defense against pathogens and the pathogenesis of inflammatory diseases, especially at body surface mucosal sites such as the airways. ILCs are activated mainly by cytokines, lipid mediators and neuropeptides that are produced by surrounding cells, and they produce large amounts of cytokines that result in inflammation. In addition, ILCs can change their phenotype in response to stimuli from surrounding cells, which enables them to respond promptly to microenvironmental changes. ILCs exhibit substantial heterogeneity, with different phenotypes and functions depending on the organ and type of inflammation, presumably because of differences in microenvironments. Thus, ILCs may be a sensitive detector of microenvironmental changes, and analysis of their phenotype and function at local sites may enable us to better understand the microenvironment in airway diseases. In this review, we aimed to identify molecules that either positively or negatively influence the function and/or plasticity of ILCs and the sources of the molecules in the airways in order to examine the pathophysiology of airway inflammatory diseases and facilitate the issues to be solved.