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1.
Cell Mol Biol (Noisy-le-grand) ; 67(4): 18-23, 2022 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-35809306

RESUMEN

Ischemia-reperfusion injury (IRI) is associated with ischemic heart disease (IHD) which leads to patients a poor progression. According to Pubmed Datasets, we analyzed different gene and mRNA expressions in IHD patients with IRI. The relevant mRNA expression detected in H9C2 cells undergo hypoxia and reoxygenation, we selected and structured miR-525-5p gene mutation H9C2 cells, the results performed miR-525-5p mutated restored H9C2 metabolism of mitochondria which detected by relevant genes and proteins. At the same time, miR-525-5p silence resisted hypoxia and reoxygenation induced H9C2 cells apoptosis. All the results indicated miR-525-5p maybe protect H9C2 cells without hypoxia and reoxygenation induced injury through regulating the mitochondria metabolism.


Asunto(s)
MicroARNs , Isquemia Miocárdica , Daño por Reperfusión Miocárdica , Apoptosis/genética , Hipoxia de la Célula/genética , Humanos , Hipoxia/genética , MicroARNs/genética , MicroARNs/metabolismo , Daño por Reperfusión Miocárdica/genética , Daño por Reperfusión Miocárdica/metabolismo , Miocitos Cardíacos/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de Señal
2.
Environ Sci Technol ; 55(8): 4190-4193, 2021 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-33733742

RESUMEN

No one can have missed the growing global environmental problems with plastics ending up as microplastics in food, water, and soil, and the associated effects on nature, wildlife, and humans. A hitherto not specifically investigated source of microplastics is polymer blends. A 1 g polymer blend can contain millions to billions of micrometer-sized species of the dispersed phase and therefore aging-induced fragmentation of the polymer blends can lead to the release of an enormous amount of microplastics. Especially if the stability of the dispersed material is higher than that of the surrounding matrix, the risk of microplastic migration is notable, for instance, if the matrix material is biodegradable and the dispersed material is not. The release can also be much faster if the matrix polymer is biodegradable. The purpose of writing this feature article is to arise public and academic attention to the large microplastic risk from polymer blends during their development, production, use, and waste handling.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Humanos , Plásticos , Polímeros , Contaminantes Químicos del Agua/análisis
3.
Adv Exp Med Biol ; 1130: 59-71, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30915701

RESUMEN

Presbycusis is a sensorineural hearing loss caused by hearing system aging and degeneration. The clinical manifestations are progressive bilateral symmetrical hearing loss, and the hearing curve is mostly slope-shaped with high-frequency reduction, sometimes flat. The results of the second national sample survey of disabled persons (2006) showed that the total number of hearing and speech disability in China was 27.8 million, accounting for 34% of the total number of disabled people in China. Among them are people over 60 years old. There are 20.4541 million people with hearing disabilities. There are 9.49 million senile deaf patients, accounting for 34.1% of the total number of hearing disabilities. As society gradually becomes aging, the incidence of presbycusis is getting higher and higher. The study of its pathogenesis is of great significance for the diagnosis, treatment, and prevention of presbycusis. The rapid progress of molecular biology experimental technology has provided us with a new opportunity to fully understand and reveal the presbycusis. In the near future, early diagnosis of presbycusis-related genes and early prevention or delay of the occurrence and development of presbycusis will become a reality.


Asunto(s)
Pérdida Auditiva Sensorineural/prevención & control , Presbiacusia/prevención & control , China , Humanos
4.
Immun Inflamm Dis ; 12(3): e1214, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38533913

RESUMEN

OBJECTIVE: Systemic lupus erythematosus (SLE) is a multisystem-involved, highly heterogeneous autoimmune disease with diverse clinical manifestations. We report an extremely rare case of SLE with severe diffuse myocardial hypertrophy. METHODS: The patient's echocardiography and cardiac magnetic resonance imaging (CMR) results indicated diffuse myocardial hypertrophy. After excluding coronary atherosclerosis, hypertensive cardiomyopathy, drug toxicity, and other causes, the patient was diagnosed with SLE-specific cardiomyopathy. Medications such as hormones, antimalarials, immunosuppressants, and biologics were administered. RESULTS: Ancillary test results were as follows: hs-cTnI: 0.054 ng/mL (0-0.016); NTproBNP: 1594.0 pg/mL (<150); A contrast-enhanced CMR revealed the diffuse thickening of the left ventricular wall with multiple abnormal enhancements, reduced left ventricular systolic and diastolic function, and moderate amount of pericardial effusion. Endomyocardial myocardial biopsy was performed, showing cardiomyocyte hypertrophy and degeneration, and no changes in myocarditis or amyloidosis. The pathology viewed by electron microscopy showed increased intracellular glycogen in the myocardium, and no hydroxychloroquine-associated damage in the myocardium. The 24-h ambulatory blood pressure and contrast-enhanced computed tomography of coronary arteries were normal. The diagnosis of SLE-specific cardiomyopathy was clear. The myocardial hypertrophy showed reversible alleviation following treatment with high-dose corticosteroids. CMR results before and after treatment were as follows: interventricular septum, pretreatment (28) versus post-treatment (22) mm; left ventricular inferior wall, pretreatment (18-21) versus post-treatment (12-14) mm; left ventricular lateral wall, pretreatment (17-18) versus post-treatment (10-12) mm; pericardial effusion (left ventricular lateral wall), pretreatment (25) versus post-treatment (12) mm; left ventricular ejection fraction, pretreatment (38.9%) versus post-treatment (66%). CONCLUSION: Myocardial hypertrophy may be an important sign of active and prognostic assessment in SLE diagnosis and management. Similarly, when encountering cases of myocardial hypertrophy, the possibility of autoimmune disease should be considered in addition to common causes.


Asunto(s)
Cardiomiopatías , Lupus Eritematoso Sistémico , Derrame Pericárdico , Humanos , Monitoreo Ambulatorio de la Presión Arterial , Cardiomiopatías/etiología , Cardiomiopatías/patología , Hipertrofia/complicaciones , Derrame Pericárdico/complicaciones , Volumen Sistólico , Función Ventricular Izquierda
5.
Heliyon ; 10(8): e29439, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38665550

RESUMEN

The uniformity of hot air flow inside the airflow dryer not only affects the moisture distribution at the outlet, but also affects the quality of the product. Based on the guide plate structure of the SH23A airflow tobacco dryer, a gradient curved guide plate dryer is designed, and the flow field distribution of the dryer is numerically investigated under different flow distribution conditions at the hot air inlet and flue gas inlet. The results show that the airflow uniformity is affected by the flow distribution at the inlet of the heated air and the inlet of the cigarette smoke, the structure of the guide plate, etc., the non-uniformity coefficient decreases with the increase of hot air inlet flow rate. The non-uniformity coefficient of tapered arc deflector decreases by 9-12 %.

6.
ACS Omega ; 9(1): 1341-1351, 2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38222641

RESUMEN

Biocomposites based on wheat gluten and reinforced with carbon fibers were produced in line with the strive to replace fossil-based plastics with microplastic-free alternatives with competing mechanical properties. The materials were first extruded/compounded and then successfully injection molded, making the setup adequate for the current industrial processing of composite plastics. Furthermore, the materials were manufactured at very low extrusion and injection temperatures (70 and 140 °C, respectively), saving energy compared to the compounding of commodity plastics. The sole addition of 10 vol % fibers increased yield strength and stiffness by a factor of 2-4 with good adhesion to the protein. The biocomposites were also shown to be biodegradable, lixiviating into innocuous molecules for nature, which is the next step in the development of sustainable bioplastics. The results show that an industrial protein coproduct reinforced with strong fibers can be processed using common plastic processing techniques. The enhanced mechanical performance of the reinforced protein-based matrix herein also contributes to research addressing the production of safe materials with properties matching those of traditional fossil-based plastics.

7.
Dose Response ; 22(2): 15593258241245804, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38617388

RESUMEN

Radiation therapy has been a critical and effective treatment for cancer. However, not all cells are destroyed by radiation due to the presence of tumor cell radioresistance. In the current study, we investigated the effect of low-dose radiation (LDR) on the tumor suppressive effect of high-dose radiation (HDR) and its mechanism from the perspective of tumor cell death mode and DNA damage repair, aiming to provide a foundation for improving the efficacy of clinical tumor radiotherapy. We found that LDR pre-irradiation strengthened the HDR-inhibited A549 cell proliferation, HDR-induced apoptosis, and G2 phase cell cycle arrest under co-culture conditions. RNA-sequencing showed that differentially expressed genes after irradiation contained pyroptosis-related genes and DNA damage repair related genes. By detecting pyroptosis-related proteins, we found that LDR could enhance HDR-induced pyroptosis. Furthermore, under co-culture conditions, LDR pre-irradiation enhances the HDR-induced DNA damage and further suppresses the DNA damage-repairing process, which eventually leads to cell death. Lastly, we established a tumor-bearing mouse model and further demonstrated that LDR local pre-irradiation could enhance the cancer suppressive effect of HDR. To summarize, our study proved that LDR pre-irradiation enhances the tumor-killing function of HDR when cancer cells and immune cells were coexisting.

8.
Int J Biol Macromol ; 262(Pt 2): 130052, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38342257

RESUMEN

Radiation-Induced Pulmonary Fibrosis (RIPF) frequently arises as a delayed complication following radiation therapy for thoracic cancers, encompassing lung, breast, and esophageal malignancies. Characterized by a relentless and irreversible accumulation of extracellular matrix (ECM) proteins within the lung parenchyma, RIPF presents a significant clinical challenge. While the modulation of gene expression by transcription factors is a recognized aspect in various pathologies, their specific role in the context of RIPF has been less clear. This study elucidates that ionizing radiation prompts the translocation of the transcription factor GATA3 into the nucleus. This translocation facilitates GATA3's binding to the NRP1 promoter, thereby enhancing the transcription and subsequent translation of NRP1. Further investigations demonstrate that the TGF-ß pathway agonist, SRI-011381, can mitigate the effects of NRP1 knockdown on epithelial-mesenchymal transition (EMT) and ECM deposition, suggesting a pivotal role of the GATA3/NRP1/TGF-ß axis in the pathogenesis of RIPF. In conclusion, our findings not only underscore the critical involvement of GATA3 in RIPF but also highlight the GATA3/NRP1/TGF-ß signaling pathway as a promising target for therapeutic intervention in RIPF management.


Asunto(s)
Fibrosis Pulmonar , Humanos , Fibrosis Pulmonar/inducido químicamente , Factor de Transcripción GATA3/genética , Factor de Transcripción GATA3/metabolismo , Factor de Transcripción GATA3/uso terapéutico , Transducción de Señal/fisiología , Pulmón/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Proteínas de la Matriz Extracelular/metabolismo , Transición Epitelial-Mesenquimal/genética
9.
Cell Death Dis ; 15(8): 619, 2024 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-39187525

RESUMEN

Despite the importance of radiation therapy as a non-surgical treatment for non-small cell lung cancer (NSCLC), radiation resistance has always been a concern, due to poor patient response and prognosis. Therefore, it is crucial to uncover novel targets to enhance radiotherapy and investigate the mechanisms underlying radiation resistance. Previously, we demonstrated that NRP1 was connected to radiation resistance in NSCLC cells. In the present study, bioinformatics analysis of constructed radiation-resistant A549 and H1299 cell models revealed that transcription coactivator YAP is a significant factor in cell proliferation and metastasis. However, there has been no evidence linking YAP and NRP1 to date. In this research, we have observed that YAP contributes to radiation resistance in NSCLC cells by stimulating cell proliferation, migration, and invasion. Mechanistically, YAP dephosphorylation after NSCLC cell radiation. YAP acts as a transcription co-activator by binding to the transcription factor TEAD4, facilitating TEAD4 to bind to the NRP1 promoter region and thereby increasing NRP1 expression. NRP1 has been identified as a new target gene for YAP/TEAD4. Notably, when inhibiting YAP binds to TEAD4, it inhibits NRP1 expression, and Rescue experiments show that YAP/TEAD4 influences NRP1 to regulate cell proliferation, metastasis and leading to radiation resistance generation. According to these results, YAP/TEAD4/NRP1 is a significant mechanism for radioresistance and can be utilized as a target for enhancing radiotherapy efficacy.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Carcinoma de Pulmón de Células no Pequeñas , Proliferación Celular , Proteínas de Unión al ADN , Neoplasias Pulmonares , Neuropilina-1 , Tolerancia a Radiación , Factores de Transcripción de Dominio TEA , Factores de Transcripción , Proteínas Señalizadoras YAP , Humanos , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Carcinoma de Pulmón de Células no Pequeñas/patología , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/genética , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/genética , Proteínas Señalizadoras YAP/metabolismo , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Neuropilina-1/metabolismo , Neuropilina-1/genética , Proteínas Musculares/metabolismo , Proteínas Musculares/genética , Regulación Neoplásica de la Expresión Génica , Línea Celular Tumoral , Movimiento Celular , Animales , Células A549 , Ratones Desnudos , Unión Proteica , Transcripción Genética/efectos de la radiación , Ratones
10.
J Hazard Mater ; 459: 132206, 2023 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-37543018

RESUMEN

Despite the significant attention given to microplastics in urban areas, our understanding of microplastics in rural drinking water systems is still limited. To address this knowledge gap, we investigated the presence and pathways of microplastics in rural drinking water system, including reservoir, water treatment plant (WTP), and tap water of end-users. The results showed that the treatment processes in the WTP, including coagulation-sedimentation, sand-granular active carbon filtration, and ultrafiltration, completely removed microplastics from the influent. However, the microplastic abundance increased during pipe transport from WTP to residents' homes, resulting in the presence of 1.4 particles/L of microplastics in tap water. This microplastic increase was also observed during the transportation from the reservoir to the WTP, suggesting that the plastic pipe network is a key source of microplastics in the drinking water system. The main types of polymers were PET, PP, and PE, and plastic breakdown, atmospheric deposition, and surface runoff were considered as their potential sources. Furthermore, this study estimated that rural residents could ingest up to 1034 microplastics annually by drinking 2 L of tap water every day. Overall, these findings provide essential data and preliminary insights into the fate of microplastics in rural drinking water systems.


Asunto(s)
Agua Potable , Contaminantes Químicos del Agua , Microplásticos , Plásticos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , China
11.
ACS Appl Mater Interfaces ; 15(2): 3455-3466, 2023 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-36538002

RESUMEN

Ionic conductive elastomers (ICEs) are emerging stretchable and ionic conductive materials that are solvent-free and thus demonstrate excellent thermal stability. Three-dimensional (3D) printing that creates complex 3D structures in free forms is considered as an ideal approach to manufacture sophisticated ICE-based devices. However, the current technologies constrain 3D printed ICE structures in a single material, which greatly limits functionality and performance of ICE-based devices and machines. Here, we report a digital light processing (DLP)-based multimaterial 3D printing capability to seemly integrate ultraviolet-curable ICE (UV-ICE) with nonconductive materials to create ionic flexible electronic devices in 3D forms with enhanced performance. This unique capability allows us to readily manufacture various 3D flexible electronic devices. To demonstrate this, we printed UV-ICE circuits into polymer substrates with different mechanical properties to create resistive strain and force sensors; we printed flexible capacitive sensors with high sensitivity (2 kPa-1) and a wide range of measured pressures (from 5 Pa to 550 kPa) by creating a complex microstructure in the dielectric layer; we even realized ionic conductor-activated four-dimensional (4D) printing by printing a UV-ICE circuit into a shape memory polymer substrate. The proposed approach paves a new efficient way to realize multifunctional flexible devices and machines by bonding ICEs with other polymers in 3D forms.

12.
Environ Manage ; 50(5): 888-99, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22961612

RESUMEN

Intensive agricultural development can change land use, which can further affect regional ecosystem services and functions. With the rapid growth of the population and the national demand for food, the northeast of China, which is located in the high latitudes, has experienced four agricultural developments since the 1950s. The original wetlands of this area were developed for farmland. The evaluation of ecosystem services is conducted to reveal the ecosystem status and variable trends caused by land reclamation. The aim of this study is to provide scientific basis for environmental management and for the sustainable development of agriculture in Northeast China. With GIS-RS technology, a typical farm was chosen to analyze variations in the ecosystem service value in response to land use changes during the study period. The total ecosystem service value of the farm decreased from 7523.10 million Yuan in 1979 to 4023.59 million Yuan in 2009 with an annual rate of -1.6 % due to the decreasing areas of woodland and wetland. The increased areas of cropland, water area and grassland partly offset the loss of the total value, but the loss was still greater than the compensation. Waste treatment and climate regulation were the top two service functions with high service values, contributing to approximately 50 % of the total service value. The spatial difference of the ecosystem service value also was analyzed. The wetlands located in the central and northeastern sections of the farm changed significantly. From the aspect of ecosystem service value, the wetland and water area should be conserved, as they have the highest value coefficients. The accuracy of the value coefficient, however, needs to be studied further in future research.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Ecosistema , Agricultura , China , Monitoreo del Ambiente , Sistemas de Información Geográfica , Humedales
13.
Water Res ; 211: 118068, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-35066257

RESUMEN

In this article, we show that enzymatic hydrolysis of a biodegradable polyester (poly(ε-caprolactone)) by Amano Lipase PS in an aqueous (buffer) environment yielded rapidly an excessive number of microplastic particles; merely 0.1 g of poly(ε-caprolactone) film was demonstrated to yield millions of particles. There were also indications of non-enzymatic hydrolysis at the same conditions, but this did not yield any particles within the time frame of the experiment (up to 6 days). Microplastic particles formed had irregular shapes with an average size of around 10 µm, with only a few reaching 60 µm. The formation of microplastic particles resulted from the uneven hydrolysis/erosion rate across the polymer film surface, which led to a rough and undulating surface with ridge, branch, and rod-shaped micro-protruding structures. The consequent detachment and fragmentation of these micro-sized protruding structures resulted in the release of microplastics to the surroundings. Together with microplastics, hydrolysis products such as acidic monomers and oligomers were also released during the enzymatic hydrolysis process, causing a pH decrease in the surrounding liquid. The results suggest that the risk of microplastic pollution from biodegradable plastics is notable despite their biodegradation. Special attention needs to be paid when using and disposing of biodegradable plastics, considering the enormous impact of the paradigm shift towards more biodegradable products on the environment.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Biodegradación Ambiental , Hidrólisis , Plásticos , Polímeros , Contaminantes Químicos del Agua/análisis
14.
Nat Commun ; 13(1): 7931, 2022 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-36566233

RESUMEN

There are growing demands for multimaterial three-dimensional (3D) printing to manufacture 3D object where voxels with different properties and functions are precisely arranged. Digital light processing (DLP) is a high-resolution fast-speed 3D printing technology suitable for various materials. However, multimaterial 3D printing is challenging for DLP as the current multimaterial switching methods require direct contact onto the printed part to remove residual resin. Here we report a DLP-based centrifugal multimaterial (CM) 3D printing method to generate large-volume heterogeneous 3D objects where composition, property and function are programmable at voxel scale. Centrifugal force enables non-contact, high-efficiency multimaterial switching, so that the CM 3D printer can print heterogenous 3D structures in large area (up to 180 mm × 130 mm) made of materials ranging from hydrogels to functional polymers, and even ceramics. Our CM 3D printing method exhibits excellent capability of fabricating digital materials, soft robots, and ceramic devices.

15.
Oxid Med Cell Longev ; 2022: 9174111, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35993027

RESUMEN

Background: Radiation resistance of lung cancer cells is a vital factor affecting the curative effect of lung cancer. Transcription factor GATA3 is involved in cell proliferation, invasion, and migration and is significantly expressed in a variety of malignancies. However, the molecular mechanism governing GATA3 regulation in lung cancer cells' radiation resistance is unknown. Methods: Radiation-resistant cell models (A549-RR and H1299-RR) were made using fractionated high-dose irradiation. Use clone formation, CCK-8, F-actin staining, cell cycle detection, and other experiments to verify whether the model is successfully constructed. Cells were transiently transfected with knockdown or overexpression plasmid. To explore the relationship between GATA3/H3K4me3 and target genes, we used ChIP-qPCR, ChIP-seq, and dual luciferase reporter gene experiments. Xenograft tumor models were used to evaluate the effect of GATA3 depletion on the tumorigenic behavior of lung cancer cells. Results: We report that transcription factors GATA3 and H3K4me3 coactivate NRP1 gene transcription when A549 cells develop radiation resistance. However, the mechanism of radiation resistance in H1299 cells is that GATA3 acts as a transcription inhibitor. The decrease of GATA3 will promote the increase of NRP1 transcription, in which H3K4me3 does not play a leading role. Conclusions: GATA3, an upstream transcriptional regulator of NRP1 gene, regulates the radioresistance of A549 and H1299 cells by opposite mechanisms, which provides a new target for radiotherapy of lung cancer.


Asunto(s)
Factor de Transcripción GATA3 , Neoplasias Pulmonares , Tolerancia a Radiación , Células A549 , Línea Celular Tumoral , Proliferación Celular/genética , Factor de Transcripción GATA3/genética , Factor de Transcripción GATA3/metabolismo , Factor de Transcripción GATA3/uso terapéutico , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/radioterapia , Tolerancia a Radiación/genética
16.
ACS Nano ; 16(8): 12471-12479, 2022 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-35904348

RESUMEN

Natural, high-performance fibers generally have hierarchically organized nanosized building blocks. Inspired by this, whey protein nanofibrils (PNFs) are assembled into microfibers, using flow-focusing. By adding genipin as a nontoxic cross-linker to the PNF suspension before spinning, significantly improved mechanical properties of the final fiber are obtained. For curved PNFs, with a low content of cross-linker (2%) the fiber is almost 3 times stronger and 4 times stiffer than the fiber without a cross-linker. At higher content of genipin (10%), the elongation at break increases by a factor of 2 and the energy at break increases by a factor of 5. The cross-linking also enables the spinning of microfibers from long straight PNFs, which has not been achieved before. These microfibers have higher stiffness and strength but lower ductility and toughness than those made from curved PNFs. The fibers spun from the two classes of nanofibrils show clear morphological differences. The study demonstrates the production of protein-based microfibers with mechanical properties similar to natural protein-based fibers and provides insights about the role of the nanostructure in the assembly process.


Asunto(s)
Iridoides , Nanoestructuras , Resistencia a la Tracción , Proteínas
17.
Nanoscale ; 14(6): 2502-2510, 2022 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-35103743

RESUMEN

Natural high-performance materials have inspired the exploration of novel materials from protein building blocks. The ability of proteins to self-organize into amyloid-like nanofibrils has opened an avenue to new materials by hierarchical assembly processes. As the mechanisms by which proteins form nanofibrils are becoming clear, the challenge now is to understand how the nanofibrils can be designed to form larger structures with defined order. We here report the spontaneous and reproducible formation of ordered microstructure in solution cast films from whey protein nanofibrils. The structural features are directly connected to the nanostructure of the protein fibrils, which is itself determined by the molecular structure of the building blocks. Hence, a hierarchical assembly process ranging over more than six orders of magnitude in size is described. The fibril length distribution is found to be the main determinant of the microstructure and the assembly process originates in restricted capillary flow induced by the solvent evaporation. We demonstrate that the structural features can be switched on and off by controlling the length distribution or the evaporation rate without losing the functional properties of the protein nanofibrils.


Asunto(s)
Nanoestructuras , Amiloide , Proteínas Amiloidogénicas , Solventes
18.
Water Res ; 198: 117123, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33865028

RESUMEN

Biodegradable polymers have been regarded as a promising solution to tackle the pollutions caused by the wide use of conventional polymers. However, during the biodegradation process, the material fragmentation leads to microplastics. In this work, the formation of microplastics from biodegradable poly (butylene adipate-co-terephthalate) (PBAT) in different aquatic environments was investigated and compared with the common non-biodegradable low-density polyethylene (LDPE). The results showed that a much larger quantity of plastic fragments/particles were formed in all aquatic environments from PBAT than from LDPE. In addition, UV-A pretreatment, simulating the exposure to sunlight, increased the rate of PBAT microplastic formation significantly. The size distribution and shapes of the formed microplastics were systematically studied, along with changes in the polymer physicochemical properties such as molecular weight, thermal stability, crystallinity, and mechanical properties, to reveal the formation process of microplastics. This study shows that the microplastic risk from biodegradable polymers is high and needs to be further evaluated with regards to longer timeframes, the biological fate of intermediate products, and final products in freshwater, estuarine and seawater natural habitats. Especially, considering that these microplastics may have good biodegradability in warmer 20 - 25° water but will most likely be highly persistent in the world's cold deep seas.


Asunto(s)
Plásticos Biodegradables , Agua Dulce , Microplásticos , Poliésteres , Agua de Mar
19.
20.
Nat Commun ; 15(1): 2052, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38448423
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