Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
J Environ Sci (China) ; 138: 439-449, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38135409

RESUMEN

The booming development of rare earth industry and the extensive utilization of its products accompanied by urban development have led to the accelerated accumulation of rare earth elements (REEs) as emerging pollutants in atmospheric environment. In this study, the variation of REEs in PM2.5 with urban (a non-mining city) transformation was investigated through five consecutive years of sample collection. The compositional variability and provenance contribution of REEs in PM2.5 were characterized, and the REEs exposure risks of children and adults via inhalation, ingestion and dermal absorption were also evaluated. The results showed an increase in the total REEs concentration from 46.46 ± 35.16 mg/kg (2017) to 81.22 ± 38.98 mg/kg (2021) over the five-year period, with Ce and La making the largest contribution. The actual increment of industrial and traffic emission source among the three pollution sources was 1.34 ng/m3. Coal combustion source displayed a downward trend. Ingestion was the main exposure pathway for REEs in PM2.5 for both children and adults. Ce contributed the most to the total intake of REEs in PM2.5 among the population, followed by La and Nd. The exposure risks of REEs in PM2.5 in the region were relatively low, but the trend of change was of great concern. It was strongly recommended to strengthen the concern about traffic-related non-exhaust emissions of particulate matter.


Asunto(s)
Contaminantes Atmosféricos , Metales de Tierras Raras , Adulto , Niño , Humanos , Contaminantes Atmosféricos/análisis , Material Particulado/análisis , Ciudades , Monitoreo del Ambiente/métodos , Metales de Tierras Raras/análisis , China
2.
Polymers (Basel) ; 16(2)2024 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-38276693

RESUMEN

Water scarcity and water pollution have become increasingly severe, and therefore, the purification of water resources has recently garnered increasing attention. Given its position as a major water resource, the efficient purification of drinking water is of crucial importance. In this study, we adopted a phase transition method to prepare ZrO2/BCM (bamboo cellulose membranes), after which we developed IP-ZrO2/BC-NFM (bamboo cellulose nanofiltration membranes) through interfacial polymerization using piperazine (PIP) and tricarbonyl chloride (TMC). Subsequently, we integrated these two membranes to create a combined "ultrafiltration + nanofiltration" membrane process for the treatment of drinking water. The membrane combination process was conducted at 25 °C, with ultrafiltration at 0.1 MPa and nanofiltration at 0.5 MPa. This membrane combination, featuring "ultrafiltration + nanofiltration," had a significant impact on reducing turbidity, consistently maintaining the post-filtration turbidity of drinking water at or below 0.1 NTU. Furthermore, the removal rates for CODMN and ammonia nitrogen reached 75% and 88.6%, respectively, aligning with the standards for high-quality drinking water. In a continuous 3 h experiment, the nanofiltration unit exhibited consistent retention rates for Na2SO4 and bovine serum protein (BSA), with variations of less than 5%, indicating exceptional separation performance. After 9 h of operation, the water flux of the nanofiltration unit began to stabilize, with a decrease rate of approximately 25%, demonstrating that the "ultrafiltration + nanofiltration" membrane combination can maintain consistent performance during extended use. In conclusion, the "ultrafiltration + nanofiltration" membrane combination exhibited remarkable performance in the treatment of drinking water, offering a viable solution to address issues related to water scarcity and water pollution.

3.
Int Immunopharmacol ; 127: 111423, 2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38141410

RESUMEN

AIM: Periodontitis is a prevalent oral immunoinflammatory condition that is distinguished by the compromised functionality of periodontal ligament stem cells (PDLSCs). Bomidin, a new recombinant antimicrobial peptide (AMP), exhibits antibacterial properties and modulates immune responses. Nevertheless, the precise anti-inflammatory impact of bomidin in periodontitis has yet to be fully elucidated. Thus, the study aimed to clarified the role of bomidin in modulating inflammation and its underlying mechanisms. METHODS: TNF-α was applied to treating PDLSCs for establishing a cell model of periodontitis. Bomidin, RSL3, ML385 and cycloheximide were also used to treat PDLSCs. Transcriptome sequencing, RT-qPCR, western blot, immunofluorescence, immunohistochemistry, Fe2+ detection probe, molecular docking, Co-IP assay, ubiquitination assay and murine models of periodontitis were used. RESULTS: Our study demonstrated that bomidin effectively suppressed inflammation in PDLSCs stimulated by TNF-α, through down-regulating the MAPK and NF-κB signaling pathways. Furthermore, bomidin exerted inhibitory effects on ferroptosis and activated the Keap1/Nrf2 pathway in the TNF-α group. There is a strong likelihood of bonding bomidin with Keap1 protein, which facilitated the degradation of Keap1 protein via the ubiquitin-proteasome pathway, leading to an enhanced translocation of Nrf2 protein to the nucleus. CONCLUSIONS: Bomidin can directly bond to Keap1 protein, resulting in the degradation of Keap1 through the ubiquitin-proteasome pathway, thereby further activating the Keap1/Nrf2 pathway. The upregulation of the Keap1/Nrf2 signaling pathway was found to contribute to the suppression of ferroptosis, ultimately alleviating inflammation in treatment of periodontitis.


Asunto(s)
Ferroptosis , Periodontitis , Ratones , Animales , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Ligamento Periodontal/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Simulación del Acoplamiento Molecular , Complejo de la Endopetidasa Proteasomal/metabolismo , Complejo de la Endopetidasa Proteasomal/farmacología , Osteogénesis , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Periodontitis/tratamiento farmacológico , Periodontitis/metabolismo , Células Madre/metabolismo , Ubiquitinas/metabolismo , Ubiquitinas/farmacología
4.
Sci Adv ; 10(26): eadk3897, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38941460

RESUMEN

The topology of the electronic band structure of solids can be described by its Berry curvature distribution across the Brillouin zone. We theoretically introduce and experimentally demonstrate a general methodology based on the measurement of energy- and momentum-resolved optical transition rates, allowing to reveal signatures of Berry curvature texture in reciprocal space. By performing time- and angle-resolved photoemission spectroscopy of atomically thin WSe2 using polarization-modulated excitations, we demonstrate that excitons become an asset in extracting the quantum geometrical properties of solids. We also investigate the resilience of our measurement protocol against ultrafast scattering processes following direct chiroptical transitions.

5.
World J Diabetes ; 15(6): 1340-1352, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38983805

RESUMEN

BACKGROUND: The mechanism of improvement of type 2 diabetes after duodenal-jejunal bypass (DJB) surgery is not clear. AIM: To study the morphological and functional changes in adipose tissue after DJB and explore the potential mechanisms contributing to postoperative insulin sensitivity improvement of adipose tissue in a diabetic male rat model. METHODS: DJB and sham surgery was performed in a-high-fat-diet/streptozotocin-induced diabetic rat model. All adipose tissue was weighed and observed under microscope. Use inguinal fat to represent subcutaneous adipose tissue (SAT) and mesangial fat to represent visceral adipose tissue. RNA-sequencing was utilized to evaluate gene expression alterations adipocytes. The hematoxylin and eosin staining, reverse transcription-quantitative polymerase chain reaction, western blot, and enzyme-linked immunosorbent assay were used to study the changes. Insulin resistance was evaluated by immunofluorescence. RESULTS: After DJB, whole body blood glucose metabolism and insulin sensitivity in adipose tissue improved. Fat cell volume in both visceral adipose tissue (VAT) and SAT increased. Compared to SAT, VAT showed more significantly functional alterations after DJB and KEGG analysis indicated growth hormone (GH) pathway and downstream adiponectin secretion were involved in metabolic regulation. The circulating GH and adiponectin levels and GH receptor and adiponectin levels in VAT increased. Cytological experiment showed that GH stimulated adiponectin secretion and improve insulin sensitivity. CONCLUSION: GH improves insulin resistance in VAT in male diabetic rats after receiving DJB, possibly by increasing adiponectin secretion.

6.
Nat Comput Sci ; 3(1): 101-114, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38177954

RESUMEN

The electronic band structure and crystal structure are the two complementary identifiers of solid-state materials. Although convenient instruments and reconstruction algorithms have made large, empirical, crystal structure databases possible, extracting the quasiparticle dispersion (closely related to band structure) from photoemission band mapping data is currently limited by the available computational methods. To cope with the growing size and scale of photoemission data, here we develop a pipeline including probabilistic machine learning and the associated data processing, optimization and evaluation methods for band-structure reconstruction, leveraging theoretical calculations. The pipeline reconstructs all 14 valence bands of a semiconductor and shows excellent performance on benchmarks and other materials datasets. The reconstruction uncovers previously inaccessible momentum-space structural information on both global and local scales, while realizing a path towards integration with materials science databases. Our approach illustrates the potential of combining machine learning and domain knowledge for scalable feature extraction in multidimensional data.


Asunto(s)
Algoritmos , Benchmarking , Bases de Datos Factuales , Electrónica , Aprendizaje Automático
7.
Int. j. morphol ; 33(4): 1460-1462, Dec. 2015. ilus
Artículo en Inglés | LILACS | ID: lil-772338

RESUMEN

The adrenal gland is an important endocrine organ in vertebratesthat produces a wide variety of hormones. The anatomical results showed that the adrenal gland in Bactrian camel had a typical blood supply and innervation. Surprisingly, we found that there was a novel connection mainly consisted of fibrous tissue, blood vessels and nerve bundles between the adrenal gland and the kidney in Bactrian camel, and we named it fibrous tissue-blood vessels-nerve bundles (FBN bundle). To the best of our knowledge, this FBN bundle was the first reported in Bactrian camel, and not yet observed in other animals. While, its functions and mechanisms should be studied further. We speculated that a direct function of this novel path might be to strengthen the communication of the adrenal gland and the kidney. So this communicationpath might have importantadaptive significance for the Bactrian camel living in arid and semi-arid ecological zones.


La glándula suprarrenal es un órgano endocrino importante en los vertebrados, que produce una amplia variedad de hormonas. Los resultados anatómicos mostraron que la glándula suprarrenal en el Camello bactriano tiene un patrón de suministro sanguíneo e inervación típico. Excepcionalmente, se encontró una conexión infrecuente que consistió principalmente en tejido fibroso, vasos sanguíneos y haces nerviosos entre la glándula suprarrenal y el riñón del Camello bactriano, denominándose haz de tejido fibroso-vasos sanguíneos-nervio (Haz FSN). Este paquete de haces de nervios es el primero reportado en el Camello bactriano, y aún no se observa en otros animales, en consecuencia sus funciones y mecanismos deben ser estudiados. Creemos que podría existir una función directa de esta nueva vía para mejorar la comunicación de la glándula suprarrenal y el riñón. Así, esta vía de comunicación podría tener un importante significado adaptativo para el Camello bactriano, quien vive en zonas ecológicas áridas y semiáridas.


Asunto(s)
Animales , Glándulas Suprarrenales/irrigación sanguínea , Glándulas Suprarrenales/inervación , Camelus/anatomía & histología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA