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1.
Nature ; 621(7979): 511-515, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37553075

RESUMEN

Plywood is widely used in construction, such as for flooring and interior walls, as well as in the manufacture of household items such as furniture and cabinets. Such items are made of wood veneers that are bonded together with adhesives such as urea-formaldehyde and phenol-formaldehyde resins1,2. Researchers in academia and industry have long aimed to synthesize lignin-phenol-formaldehyde resin adhesives using biomass-derived lignin, a phenolic polymer that can be used to substitute the petroleum-derived phenol3-6. However, lignin-phenol-formaldehyde resin adhesives are less attractive to plywood manufacturers than urea-formaldehyde and phenol-formaldehyde resins owing to their appearance and cost. Here we report a simple and practical strategy for preparing lignin-based wood adhesives from lignocellulosic biomass. Our strategy involves separation of uncondensed or slightly condensed lignins from biomass followed by direct application of a suspension of the lignin and water as an adhesive on wood veneers. Plywood products with superior performances could be prepared with such lignin adhesives at a wide range of hot-pressing temperatures, enabling the use of these adhesives as promising alternatives to traditional wood adhesives in different market segments. Mechanistic studies indicate that the adhesion mechanism of such lignin adhesives may involve softening of lignin by water, filling of vessels with softened lignin and crosslinking of lignins in adhesives with those in the cell wall.


Asunto(s)
Adhesivos , Lignina , Madera , Adhesivos/química , Formaldehído/química , Lignina/química , Fenoles/química , Urea/química , Agua/química , Madera/química , Biomasa , Calor
2.
BMC Cancer ; 24(1): 583, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38741082

RESUMEN

BACKGROUND: Insufficient evidence existed about the prognostic role of the advanced lung cancer inflammation index (ALI) for gastric cancer patients who underwent curative resection. The aim of this study was to identify the predictive ability of ALI for survival after curative gastrectomy. METHODS: We retrospectively analyzed 328 gastric cancer patients who received curative gastrectomy from the database of Chongqing University Cancer Hospital, and investigated the prognostic role of the preoperative ALI compared with clinicopathological variables and other serum biomarkers, such as preoperative neutrophil-to-lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and Lymphocyte-monocyte ratio (LMR). To minimize intergroup differences, propensity score matching (PSM) analysis was employed. Additionally, we performed a meta-analysis of four cohort studies published up to October 2023 following the PRISMA guidelines. RESULTS: In the overall cohort, patients in the low ALI group had a significantly worse overall survival compared to those in the high ALI group (P < 0.0001). Subgroup analysis identified that ALI maintained its prognostic significance across different subgroups. In addition, ROC analysis showed that ALI had a higher AUC value for 3-year overall survival compared to NLR, PLR, and LMR (0.576 vs. 0.573 vs. 0.557 vs. 0.557). Multivariate analysis indicated that ALI, other than other serum biomarkers, was an independent risk factor for decreased overall survival in GC patients following curative surgery (HR = 1.449; 95%CI: 1.028-2.045; P = 0.034). Consistently, PSM analysis supported all of these findings. The meta-analysis including 4 studies evaluating 2542 patients, confirmed the association between the low ALI and poor survival outcomes. CONCLUSION: The preoperative ALI was an independent prognostic factor for survival in gastric cancer patients who underwent curative gastrectomy.


Asunto(s)
Gastrectomía , Puntaje de Propensión , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/cirugía , Neoplasias Gástricas/mortalidad , Neoplasias Gástricas/sangre , Neoplasias Gástricas/patología , Pronóstico , Masculino , Femenino , Persona de Mediana Edad , Estudios Retrospectivos , Inflamación/sangre , Anciano , Neutrófilos , Linfocitos
3.
Biomacromolecules ; 25(7): 4384-4393, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38822786

RESUMEN

Traditional hydrogel-based wearable sensors with flexibility, biocompatibility, and mechanical compliance exhibit potential applications in flexible wearable electronics. However, the low sensitivity and poor environmental resistance of traditional hydrogels severely limit their practical application. Herein, high-ion-conducting poly(vinyl alcohol) (PVA) nanocomposite hydrogels were fabricated and applied for harsh environments. MXene ion-conducting microchannels and poly(sodium 4-styrenesulfonate) ion sources contributed to the directional transport of abundant free ions in the hydrogel, which significantly improved the sensitivity and mechanical-electric conversion of the nanocomposite hydrogel-based piezoelectric and triboelectric sensors. More importantly, the glycerol as an antifreezing agent enabled the hydrogel-based sensors to function in harsh environments. Therefore, the nanocomposite hydrogel exhibited high gauge factor (GF) at -20 °C (GF = 3.37) and 60 °C (GF = 3.62), enabling the hydrogel-based sensor to distinguish different writing letters and sounding words. Meanwhile, the hydrogel-based piezoelectric and triboelectric generators showed excellent mechanical-electric conversion performance regardless of low- (-20 °C) or high- (60 °C) temperature environments, which can be applied as a visual feedback system for information transmission without external power sources. This work provides self-powered nanocomposite hydrogel-based sensors that exhibit potential applications in flexible wearable electronics under harsh environmental conditions.


Asunto(s)
Hidrogeles , Nanocompuestos , Alcohol Polivinílico , Dispositivos Electrónicos Vestibles , Nanocompuestos/química , Alcohol Polivinílico/química , Hidrogeles/química , Conductividad Eléctrica , Humanos
4.
World J Surg Oncol ; 22(1): 143, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38812025

RESUMEN

BACKGROUND: ​The applicability of laparoscopy to nonmetastatic T4a patients with gastric cancer remains unclear due to the lack of high-quality evidence. The purpose of this study was to compare the survival rates of laparoscopic gastrectomy (LG) versus open gastrectomy (OG) for these patients through a meta-analysis of reconstructed individual participant data from propensity score-matched studies. METHODS: PubMed, Embase, Web of Science, Cochrane library and CNKI were examined for relevant studies without language restrictions through July 25, 2023. Individual participant data on overall survival (OS) and disease-free survival (DFS) were extracted from the published Kaplan-Meier survival curves. One-stage and two-stage meta-analyses were performed. In addition, data regarding surgical outcomes and recurrence patterns were also collected, which were meta-analyzed using traditional aggregated data. RESULTS: Six studies comprising 1860 patients were included for analysis. In the one-stage meta-analyses, the results demonstrated that LG was associated with a significantly better DFS (Random-effects model: P = 0.027; Restricted mean survival time [RMST] up to 5 years: P = 0.033) and a comparable OS (Random-effects model: P = 0.135; RMST up to 5 years: P = 0.053) than OG for T4a gastric cancer patients. Two-stage meta-analyses resulted in similar results, with a 13% reduced hazard of cancer-related death (P = 0.04) and 10% reduced hazard of overall mortality (P = 0.11) in the LG group. For secondary outcomes, the pooled results showed an association of LG with less estimated blood loss, faster postoperative recovery and more retrieved lymph nodes. CONCLUSION: Laparoscopic surgery for patients with nonmetastatic T4a disease is associated with a potential survival benefit and improved surgical outcomes.


Asunto(s)
Gastrectomía , Laparoscopía , Neoplasias Gástricas , Humanos , Gastrectomía/métodos , Gastrectomía/mortalidad , Laparoscopía/métodos , Laparoscopía/mortalidad , Estadificación de Neoplasias , Pronóstico , Puntaje de Propensión , Neoplasias Gástricas/cirugía , Neoplasias Gástricas/patología , Neoplasias Gástricas/mortalidad , Tasa de Supervivencia
5.
Nano Lett ; 23(22): 10297-10304, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37955657

RESUMEN

Low-grade heat exists ubiquitously in the environment, and gel-state thermogalvanic cells (GTCs) can directly convert thermal energy into electricity by a redox reaction. However, their low ionic conductivity and poor mechanical properties are still insufficient for their potential applications. Here, we designed a bacterial cellulose (BC) nanofiber-macromolecular entanglement network to balance the GTC's thermopower and mechanical properties. Therefore, the BC-GTC shows a Seebeck coefficient of 3.84 mV K-1, an ionic conductivity of 108.5 mS cm-1, and a high specific output power density of 1760 µW m-2 K-2, which are much higher than most current literature. Further connecting 15 units of BC-GTCs, the output voltage of 3.35 V can be obtained at a temperature gradient of 65 K, which can directly power electronic devices such as electronic calculators, thermohydrometers, fans, and light-emitting diodes (LEDs). This work offers a promising method for developing high-performance and durable GTC in sustainable green energy.

6.
J Environ Manage ; 366: 121807, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39025011

RESUMEN

The removal of various pollutants from water is necessary due to the increasing requirements for the removal of various pollutants from wastewater and the quality of drinking water. Polymer microspheres are regarded as exemplary adsorbent materials due to their high adsorption efficiency, excellent adsorption performance, and ease of handling. Herein, the advantages and disadvantages of different preparation methods, modifications, applications and the current research status of polymer microspheres are summarized at large. Furthermore, the enhanced performance of modified composite microspheres is emphasized, including adsorption efficiency, thermal stability, and significant improvements in physical and chemical properties. Subsequently, the current applications and potential of polymeric microspheres for wastewater treatment, including the removal of inorganic and organic pollutants, heavy metal ions, and other contaminants are summarized. Finally, future research directions for polymer microspheres are proposed, outlining the challenges and solutions associated with the application of polymer microspheres in wastewater treatment.

7.
World J Surg Oncol ; 21(1): 166, 2023 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-37270519

RESUMEN

BACKGROUND: The role of prophylactic drainage (PD) in gastrectomy for gastric cancer (GC) is not well-established. The purpose of this study is to compare the perioperative outcomes between the PD and non-drainage (ND) in GC patients undergoing gastrectomy. METHODS: A systematic review of electronic databases including PubMed, Embase, Web of Science, the Cochrane Library, and China National Knowledge Infrastructure was performed up to December 2022. All eligible randomized controlled trials (RCTs) and observational studies were included and meta-analyzed separately. The registration number of this protocol is PROSPERO CRD42022371102. RESULTS: Overall, 7 RCTs (783 patients) and 14 observational studies (4359 patients) were ultimately included. Data from RCTs indicated that patients in the ND group had a lower total complications rate (OR = 0.68; 95%CI:0.47-0.98; P = 0.04; I2 = 0%), earlier time to soft diet (MD = - 0.27; 95%CI: - 0.55 to 0.00; P = 0.05; I2 = 0%) and shorter length of hospital stay (MD = - 0.98; 95%CI: - 1.71 to - 0.26; P = 0.007; I2 = 40%). While other outcomes including anastomotic leakage, duodenal stump leakage, pancreatic leakage, intra-abdominal abscess, surgical-site infection, pulmonary infection, need for additional drainage, reoperation rate, readmission rate, and mortality were not significantly different between the two groups. Meta-analyses on observational studies showed good agreement with the pooled results from RCTs, with higher statistical power. CONCLUSION: The present meta-analysis suggests that routine use of PD may not be necessary and even harmful in GC patients following gastrectomy. However, well-designed RCTs with risk-stratified randomization are still needed to validate the results of our study.


Asunto(s)
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/cirugía , Ensayos Clínicos Controlados Aleatorios como Asunto , Gastrectomía/métodos , Drenaje/métodos , Fuga Anastomótica/cirugía , Complicaciones Posoperatorias/prevención & control
8.
Int J Mol Sci ; 24(19)2023 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-37833891

RESUMEN

Bone morphogenetic proteins (BMPs) are a group of structurally and functionally related signaling molecules that comprise a subfamily, belonging to the TGF-ß superfamily. Most BMPs play roles in the regulation of embryonic development, stem cell differentiation, tumor growth and some cardiovascular and cerebrovascular diseases. Although evidence is emerging for the antiviral immunity of a few BMPs, more BMPs are needed to determine whether this function is universal. Here, we identified the zebrafish bmp4 ortholog, whose expression is up-regulated through challenge with grass carp reovirus (GCRV) or its mimic poly(I:C). The overexpression of bmp4 in epithelioma papulosum cyprini (EPC) cells significantly decreased the viral titer of GCRV-infected cells. Moreover, compared to wild-type zebrafish, viral load and mortality were significantly increased in both larvae and adults of bmp4-/- mutant zebrafish infected with GCRV virus. We further demonstrated that Bmp4 promotes the phosphorylation of Tbk1 and Irf3 through the p38 MAPK pathway, thereby inducing the production of type I IFNs in response to virus infection. These data suggest that Bmp4 plays an important role in the host defense against virus infection. Our study expands the understanding of BMP protein functions and opens up new targets for the control of viral infection.


Asunto(s)
Proteínas Morfogenéticas Óseas , Inmunidad Innata , Pez Cebra , Animales , Proteínas Morfogenéticas Óseas/metabolismo , Proteínas Quinasas Activadas por Mitógenos , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Reoviridae/fisiología , Virosis/genética , Pez Cebra/genética , Pez Cebra/metabolismo
9.
BMC Oral Health ; 23(1): 519, 2023 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-37491232

RESUMEN

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a disease with increasing incidence worldwide that leads to deformity and death. In OSCC, fascin actin-bundling protein 1 (FSCN1) is an oncogene involved in the tumorigenesis process. However, the functions and potential mechanisms of FSCN1 in the OSCC tumorigenesis process have not been reported thus far. METHODS: We used qRT‒PCR to detect the expression of FSCN1 in 40 paired OSCC tumor tissues (tumor) and neighboring noncancerous tissues. The role of FSCN1 was also assessed in vitro through colony formation, CCK-8, and transwell assays. Moreover, glucose consumption was detected. Western blotting was used to confirm the interaction of FSCN1, IRF4 and AKT. RESULTS: FSCN1 was remarkably overexpressed in OSCC tissues and cell lines compared to corresponding controls. In addition, colony formation, CCK-8, and transwell assays revealed a notable reduction in OSCC growth and invasion when FSCN1 was silenced. FSCN1 silencing remarkably suppressed OSCC glycolysis. Mechanistic studies showed that FSCN1 achieves its function partially by activating interferon regulatory factor 4 (IRF4) and the AKT pathway in OSCC. CONCLUSION: In conclusion, our study investigated the functions and mechanisms of the FSCN1/IRF4/AKT pathway in OSCC progression. In OSCC, FSCN1 is likely to be a biomarker and therapeutic target.


Asunto(s)
Neoplasias de la Boca , Carcinoma de Células Escamosas de Cabeza y Cuello , Humanos , Carcinogénesis , Proteínas Portadoras/metabolismo , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Glucólisis , Factores Reguladores del Interferón/genética , Factores Reguladores del Interferón/metabolismo , Neoplasias de la Boca/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Carcinoma de Células Escamosas de Cabeza y Cuello/patología
10.
Chem Rec ; 22(4): e202100276, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34962071

RESUMEN

Lewis base catalysis provides powerful synthetic strategies for the selective construction of carbon-carbon and carbon-heteroatom bonds. Thus continuous efforts have been deployed to develop effective methodologies involving Lewis base catalysis. The nucleophilicity and steric hindrance of Lewis base catalyst often plays a major role in catalytic reactivity and selectivity in the reaction. In the past decades, tremendous progress has been made in the divergent construction of valuable motifs under Lewis base catalysis. In this review, we provide a comprehensive and updated summary of Lewis base-catalysed chemo-, diastereo- and enantiodivergent reaction, as well as the related mechanism will be highlighted in detail.

11.
Biomacromolecules ; 23(6): 2272-2279, 2022 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-35486379

RESUMEN

Smart functional fillers can significantly enhance the comprehensive properties of ionic hydrogels, such as their mechanical properties, which are key features of hydrogels in wearable sensor applications. As a plant-derived natural polymer, hemicellulose can serve as smart functional fillers. In this study, tannic acid-modified hemicellulose nanoparticles (TA@HC) and Fe3+ were used in the preparation of PAA/TA@HC/Fe3+ hydrogels. The addition of TA@HC and Fe3+ in the sodium persulfate (SPS) and acrylic acid (AA) polymerization system resulted in a fast gelation process that was completed within a short time (as short as 30 s) at room temperature. The catechol-rich TA and Fe3+ system allows for quick activation of SPS to produce free radicals, generating abundant hydroxyl groups in a short period of time, which was responsible for the fast gelation. Furthermore, due to the TA@HC effect and the dynamic catechol (TA)-Fe3+ redox system, the PAA/TA@HC/Fe3+ hydrogel exhibited excellent mechanical properties with an exceptionally high strain (as high as 5600%), adhesiveness, rapid and efficient self-healing ability, and reproducible self-adhesion onto various substrates. More importantly, asymmetric adhesive PAA/TA@HC/Fe3+ hydrogels were prepared by selective Fe3+ coating of the upper hydrogel surface to render the top surface nonadhesive so that the same hydrogel with different adhesiveness between the upper and bottom surfaces was obtained. The asymmetric adhesive hydrogel design permits the adhesive side to fit comfortably to the skin and the nonadhesive side showing anti-interference against various different pollutant materials, accurately serving as a pressure sensor.


Asunto(s)
Hidrogeles , Nanopartículas , Adhesivos/química , Catecoles , Hidrogeles/química , Iones/química , Polisacáridos
12.
Inorg Chem ; 61(24): 9063-9072, 2022 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-35671331

RESUMEN

Copper-deficient Cu2-xS nanoparticles (NPs) are extensively exploited as a superior cation exchange (CE) template to yield sophisticated nanostructures. Recently, it has been discovered that their CE reactions can be facilely manipulated by copper vacancy density, morphology, and NP size. However, the structural similarity of usually utilized Cu2-xS somewhat limits the manipulation of the CE reactions through the factor of crystal structure because it can strongly influence the process of the reaction. Herein, we report a methodology of crystal structure transformation to manipulate the CE reactions. Particularly, roxbyite Cu1.8S nanodisks (NDs) were converted into solid wurtzite CdS NDs and Janus-type Cu1.94S/CdS NDs by a "full"/partial CE reaction with Cd2+. Afterward, the roxbyite Cu1.8S were pseudomorphically transformed into covellite CuS NDs. Unlike Cu1.8S, the CuS was scarcely exchanged because of the unique disulfide (S-S) bonds and converted into hollow wurtzite CdS under a more reactive condition. The S-S bonds were gradually split and CuS@CdS core@shell-type NDs were generated. Therefore, our findings in the present study provide not only a versatile technique to manipulate CE reactions in Cu2-xS NPs but also a better comprehension of their reaction dynamics and pathways.

13.
Nanotechnology ; 33(15)2022 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-34963111

RESUMEN

Herein, electrochemical synthesis of tungsten trioxide (WO3) with globular clusters constructed of nanoplates is demonstrated. Under a breakdown anodization potential of 25 V at 50 °C, tungsten foil anode was efficiently electro-oxidized into WO3nanoplates-aggragated globular clusters powder, rather than a thin film structure as conventional anodization occurs. The WO3globular clusters were characterized by SEM, TEM, and XRD. Effects of electrolyte composition on the breakdown anodization of the W substrate has been discussed. It is suggested that the growth of the WO3nanoplates is initiated by localized anodic dielectric breakdown, and followed by an effective crystal growth in the electrolyte at high breakdown field.

14.
Molecules ; 27(23)2022 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-36500264

RESUMEN

Areca nut (AN) is widely consumed all over the world, bringing great harm to human health and economy. Individuals with AN chewing are at high risk of cardiovascular disease and impaired immune system and metabolic system. Despite a growing number of studies having reported on the adverse effects brought by AN chewing, the exact mechanism of it is limited and the need for additional exploration remains. In recent years, the interaction between microorganisms, especially intestinal microorganism and host, has been extensively studied. AN chewing might disrupt the oral and intestinal microbiota communities through direct connect with the microbes it contains, altering PH, oxygen of oral and intestinal microenvironment, and disturbing the immune homeostasis. These mechanisms provide insights into the interplay between areca nut and host microbiota. Emerging studies have proposed that bidirectional interaction between polyphenols and intestinal microbes might play a potential role in the divergence of polyphenol, extracted from AN, among individuals with or without AN-induced cancer development and progression. Although some AN chewers have been aware of the harmful effects brought by AN, they cannot abolish this habit because of the addiction of AN. Increasing studies have tried to revealed that gut microbiota might influence the onset/development of addictive behaviors. Altogether, this review summarizes the possible reasons for the disturbance of host microbiota caused by areca nut chewing and clarifies the complex interaction between human microbiome and major constituents and the addiction and carcinogenicity of AN, tempting to provide novel insights into the development and utilization of it, and to control the adverse consequences caused by AN chewing.


Asunto(s)
Conducta Adictiva , Microbiota , Humanos , Areca/efectos adversos , Masticación , Polifenoles
15.
Chemistry ; 27(3): 1057-1065, 2021 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-33051913

RESUMEN

For plasmonic copper-deficient Cu2-x S nanoparticles (NPs), accurate control of the crystal phase and morphology is highly desirable as both of which are known to determine the localized surface plasmon resonance (LSPR) wavelength and amplitude. Here, how the sulfur precursor reactivity in the synthesis of Cu2-x S NPs affects the resulting crystal phase and morphology is examined. Djurleite Cu1.94 S, roxbyite Cu1.8 S, digenite Cu1.8 S as well as covellite CuS nanodisks were synthesized by using 1-dodecanethiol, N,N-dibutylthiourea, and crystal sulfur 1-octadecene/oleylamine solutions and their crystal phase dependent LSPR properties were exhaustively discussed. In addition, crystal phase interconversion between covellite CuS and djurleite/roxbyite Cu2-x S was realized in the presence of the above sulfur precursors. On the other hand, djurleite Cu1.94 S nanorods rather than nanodisks were prepared by replacing 1-dodecanethiol with more reactive tert-dodecanethiol. The structural and morphological Cu2-x S NPs here holds great promise in the application of photothermal therapy, photocatalysis, surface-enhanced Raman scattering (SERS), and many others.

16.
Chemistry ; 27(26): 7444-7452, 2021 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-33686735

RESUMEN

A crucial parameter in the design of semiconductor nanoparticles (NPs) with controllable optical, magnetic, electronic, and catalytic properties is the morphology. Herein, we demonstrate the potential of additive metal cations with variable valency to direct the morphology evolution of copper-deficient Cu2-x S nanoparticles in the process of seed-mediated growth. In particular, the djurleite Cu1.94 S seed could evolve from disk into tetradecahedron in the presence of tin(IV) cations, whereas they merely formed sharp hexagonal nanodisks with tin(II) cations. In addition to djurleite Cu1.94 S, the tin(IV) cations could be generalized to direct the growth of roxbyite Cu1.8 S and covellite CuS nanodisk seeds into tetradecahedra. We further perform pseudomorphic cation exchanges of Cu1.94 S tetradecahedra with Zn2+ and Cd2+ to produce polyhedral zinc sulfide (ZnS) and cadmium sulfide (CdS) NPs. Moreover, we achieve Cu1.8 S/ZnS and Cu1.94 S/CdS tetradecahedral heterostructures via partial cation exchange, which are otherwise inaccessible by traditional synthetic approaches.

17.
Proc Natl Acad Sci U S A ; 115(35): 8682-8687, 2018 08 28.
Artículo en Inglés | MEDLINE | ID: mdl-30104354

RESUMEN

The extreme Sr, Nd, Hf, and Pb isotopic compositions found in Pitcairn Island basalts have been labeled enriched mantle 1 (EM1), characterizing them as one of the isotopic mantle end members. The EM1 origin has been vigorously debated for over 25 years, with interpretations ranging from delaminated subcontinental lithosphere, to recycled lower continental crust, to recycled oceanic crust carrying ancient pelagic sediments, all of which may potentially generate the requisite radiogenic isotopic composition. Here we find that δ26Mg ratios in Pitcairn EM1 basalts are significantly lower than in normal mantle and are the lowest values so far recorded in oceanic basalts. A global survey of Mg isotopic compositions of potentially recycled components shows that marine carbonates constitute the most common and typical reservoir invariably characterized by extremely low δ26Mg values. We therefore infer that the subnormal δ26Mg of the Pitcairn EM1 component originates from subducted marine carbonates. This, combined with previously published evidence showing exceptionally unradiogenic Pb as well as sulfur isotopes affected by mass-independent fractionation, suggests that the Pitcairn EM1 component is most likely derived from late Archean subducted carbonate-bearing sediments. However, the low Ca/Al ratios of Pitcairn lavas are inconsistent with experimental evidence showing high Ca/Al ratios in melts derived from carbonate-bearing mantle sources. We suggest that carbonate-silicate reactions in the late Archean subducted sediments exhausted the carbonates, but the isotopically light magnesium of the carbonate was incorporated in the silicates, which then entered the lower mantle and ultimately became the Pitcairn plume source.

18.
Cellulose (Lond) ; 28(3): 1527-1540, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33424143

RESUMEN

Hydrogels are attractive due to their various applications in the fields of biomedical materials, cosmetics, and biosensors. To enhance UV protection and prevent skin penetration behaviors, inspired by the mussel adhesive proteins, the functional polydopamine (PDA) is employed herein to fabricate polydopamine/carboxymethyl cellulose/polyacrylic acid (PDA/CMC/PAA) adhesive hydrogels. To disperse PDA nanoparticles well in the PAA matrix, dopamine was self-polymerized in CMC solution to form PDA/CMC complex. Acrylic acid was polymerized in PDA/CMC complex solution and cross-linked to construct UV-resistant PDA/CMC/PAA hydrogel. The morphology, rheological behavior, mechanical properties and adhesion strength of PDA/CMC/PAA hydrogels were studied by scanning electron microscopy, rotational rheometer, universal test machine. Owing to the hydrogen bonding interaction between the PDA/CMC complex and PAA, the PDA/CMC/PAA hydrogels showed high resilience and compressive strength to withstand large deformation. The hydrogels exhibited strong adhesion to various substrate surfaces, such as stainless steel, aluminum, glass and porcine skin. The biocompatibility and UV-shielding properties were investigated through culture of cells and UV irradiation test. The adhesiveness of PDA promoted cell adhesion and provided the PDA/CMC/PAA hydrogels good biocompatibility with 96% of relative cell viability. The hydrogels possessed excellent UV-shielding ability to prevent collagen fibers from being destroyed during UV irradiation, which has promising potential in the practical applications for UV filtration membrane and skin care products.

19.
BMC Musculoskelet Disord ; 21(1): 150, 2020 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-32143603

RESUMEN

BACKGROUND: Rheumatoid arthritis is a long-term, progressive autoimmune disease. It is characterized by synovial hyperplasia leading to swelling, stiffness, and joint deformity in more than one joint. Fibroblast-like synoviocytes are the major cell types that make up the synovial intima structure, which is one of the decisive factors in the development and course of rheumatoid arthritis. METHODS: The potential therapeutic effects of MSCs-derived miRNA-124a overexpression exosomes were evaluated in vitro by the method including MTT assay and cell cycle test for cell proliferation, scratch wound closure and transwell for cell migration, flow cytometry and western for the apoptosis detection. RESULTS: Exosomes derived from human MSCs that overexpression miRNA-124a were prepared and characterized. We found that the pretreatment of this exosome was able to inhibit the proliferation and migration of fibroblast-like synoviocyte cell line and promote the apoptosis of this cell during the co-incubation. CONCLUSIONS: Exosomes derived from MSCs were proved to be a suitable vector for the delivery of therapeutic miRNA-124a, and such miRNA-124a overexpression exosomes were expected to provide a new medicine and strategy for the treatment of rheumatoid arthritis.


Asunto(s)
Artritis Reumatoide/metabolismo , Movimiento Celular/genética , Proliferación Celular/genética , Exosomas/metabolismo , Fibroblastos/metabolismo , Células Madre Mesenquimatosas/metabolismo , MicroARNs/metabolismo , Sinoviocitos/metabolismo , Apoptosis/genética , Artritis Reumatoide/patología , Puntos de Control del Ciclo Celular/genética , Línea Celular , Técnicas de Cocultivo , Humanos , MicroARNs/genética , Transfección
20.
J Environ Manage ; 241: 59-75, 2019 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-30981144

RESUMEN

In this review article, a significant number of published articles (over three decades) were consulted in order to provide comprehensive literature information about chlorophenols, their sources into the environment, classification, and toxicity, various wastewater treatment methods for their removal as well as the characteristics of their adsorption by various adsorbents. Organizing the scattered available information on a wide range of potentially effective adsorbents in the removal of chlorophenols is the principal objective of this article. Various adsorbents such as natural materials, waste materials from industries, agricultural by-products and biomass-based activated carbon in the removal of various chlorophenols have been compiled and discussed here. Crucial factors like temperature, solution pH, contact time and initial solution concentration are also reported and discussed here. The π-π dispersion interaction mechanism, hydrogen bonding formation mechanism, and the electron donor-acceptor complex mechanism were proposed for the chlorophenols adsorption onto various adsorbents with the help of current literature. Conclusions have been drawn proposing a few suggestions for future research on mitigating the effect of chlorophenols in the environment.


Asunto(s)
Clorofenoles , Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Aguas Residuales
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