Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
Regen Biomater ; 11: rbad105, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38173772

RESUMEN

Sol-gel borate bioactive glasses (BGs) are promising ion-releasing biomaterials for wound healing applications. Here, we report the synthesis of a series of binary B2O3-CaO borate BGs (CaO ranging from 50 to 90 mol%) using a sol-gel-based method. The influence of CaO content in B2O3-CaO borate BG on morphology, structure and ion release behavior was investigated in detail. Reduced dissolution (ion release) and crystallization could be observed in borate BGs when CaO content increased, while the morphology was not significantly altered by increasing CaO content. Our results evidenced that the ion release behavior of borate BGs could be tailored by tuning the B2O3/CaO molar ratio. We also evaluated the in vitro cytotoxicity, hemostatic, antibacterial and angiogenic activities of borate BGs. Cytocompatibility was validated for all borate BGs. However, borate BGs exhibited composition-dependent hemostatic, antibacterial and angiogenic activities. Generally, higher contents of Ca in borate BGs facilitated hemostatic activity, while higher contents of B2O3 were beneficial for pro-angiogenic activity. The synthesized sol-gel-derived borate BGs are promising materials for developing advanced wound healing dressings, given their fast ion release behavior and favorable hemostatic, antibacterial and angiogenic activities.

2.
Acta Biomater ; 174: 412-427, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38040077

RESUMEN

Bioactive glass nanoparticles (BGNs) are well-recognized multifunctional biomaterials for bone tissue regeneration due to their capability to stimulate various cellular processes through released biologically active ions. Understanding the correlation between BGN composition and cellular responses is key to developing clinically usable BGN-based medical devices. This study investigated the influence of CaO content of binary SiO2-CaO BGNs (CaO ranging from 0 to 10 mol%) on osteogenic differentiation of rat bone marrow mesenchymal stem cells (rBMSCs) and in vivo bone regeneration in zebrafish osteoporosis model. The results showed that BGNs could promote osteogenic differentiation of rBMSCs by indirectly releasing active ions or directly interacting with rBMSCs by internalization. In both situations, BGNs of a higher CaO content could promote the osteogenic differentiation of rBMSCs to a greater extent. The internalized BGNs could activate the transcription factors RUNX2 and OSX, leading to the expression of osteogenesis-related genes. The results in the zebrafish osteoporosis model indicated that the presence of BGNs of higher CaO contents could enhance bone regeneration and rescue dexamethasone-induced osteoporosis to a greater extent. These findings demonstrate that BGNs can stimulate osteogenic differentiation of rBMSCs by releasing active ions or internalization. A higher CaO content facilitates osteogenesis and bone regeneration of zebrafish as well as relieving dexamethasone-induced osteoporosis. The zebrafish osteoporosis model can be a potent tool for evaluating the in vivo bone regeneration effects of bioactive materials. STATEMENT OF SIGNIFICANCE: Bioactive glass nanoparticles (BGNs) are increasingly used as fillers of nanocomposites or as delivery platforms of active ions to regenerate bone tissue. Various studies have shown that BGNs can enhance osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) by releasing active ions. However, the correlation between BGN composition and cellular responses and in vivo bone regeneration effect has still not been well investigated. Establishment of a suitable in vivo animal model for investigating this correlation is also challenging. The present study reports the influence of CaO content in binary SiO2-CaO BGNs on osteogenic differentiation of BMSCs extracellularly and intracellularly. This study also demonstrates the suitability of zebrafish osteoporosis model to investigate in vivo bone regeneration effect of BGNs.


Asunto(s)
Células Madre Mesenquimatosas , Nanopartículas , Osteoporosis , Ratas , Animales , Osteogénesis , Pez Cebra , Dióxido de Silicio/farmacología , Regeneración Ósea , Vidrio , Diferenciación Celular , Células de la Médula Ósea , Osteoporosis/terapia , Osteoporosis/metabolismo , Iones/farmacología , Dexametasona/farmacología , Células Cultivadas
3.
J Hazard Mater ; 464: 132994, 2024 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-37988943

RESUMEN

Microplastics (MPs) and antibiotics are ubiquitous in aquatic ecosystems, and their accumulation and combined effects are considered emerging threats that may affect biodiversity and ecosystem function. The particle size of microplastics plays an important role in their combined effects with antibiotics. Submerged macrophytes are crucial in maintaining the health and stability of freshwater ecosystems. However, little is known about the combined effects of different particle size of MPs and antibiotics on freshwater plants, particularly their effects on submerged macrophyte communities. Thus, there is an urgent need to study their effects on the macrophyte communities to provide essential information for freshwater ecosystem management. In the present study, a mesocosm experiment was conducted to explore the effects of three particle sizes (5 µm, 50 µm, and 500 µm) of polystyrene-microplastics (PSMPs) (75 mg/L), tetracycline (TC) (50 mg/L), and their co-pollutants on interactions between Hydrilla verticillata and Elodea nuttallii. Our results showed that the effects of MPs are size-dependent on macrophytes at the community level rather than at the population level, and that small and medium sized MPs can promote the growth of the two test macrophytes at the community level. In addition, macrophytes at the community level have a stronger resistance to pollutant stress than those at the population level. Combined exposure to MPs and TC co-pollutants induces species-specific responses and antagonistic toxic effects on the physio-biochemical traits of submerged macrophytes. Our study provides evidence that MPs and co-pollutants not only affect the morphology and physiology at the population level but also the interactions between macrophytes. Thus, there are promising indications on the potential consequences of MPs and co-pollutants on macrophyte community structure, which suggests that future studies should focus on the effects of microplastics and their co-pollutants on aquatic macrophytes at the community level rather than only at the population level. This will improve our understanding of the profound effects of co-pollutants in aquatic environments on the structure and behavior of aquatic communities and ecosystems.


Asunto(s)
Ecosistema , Contaminantes Ambientales , Microplásticos/toxicidad , Plásticos/toxicidad , Tamaño de la Partícula , Inhibidores de la Síntesis de la Proteína , Antibacterianos , Tetraciclinas
4.
Colloids Surf B Biointerfaces ; 234: 113714, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38128358

RESUMEN

Binary SiO2-CaO mesoporous bioactive glass nanoparticles (MBGNs) are multifunctional biomaterials able to promote osteogenic, angiogenic, and immunomodulatory activities. MBGNs have been applied in a variety of tissue regeneration strategies. However, MBGNs lack strong antibacterial activity and current strategies (loading of antibacterial ions or antibiotics) toward enhanced antibacterial activity may cause cytotoxicity or antibiotic resistance. Here we engineered MBGNs using bacteriophages (phages) to enhance the antibacterial activity. Salmonella Typhimurium (S. T) phage PFPV25.1 that can infect Salmonella enterica serovar Typhimurium strain LT2 was used as a model phage to engineer MBGNs. MBGNs were first modified with amine groups to enhance the affinity between phages and MBGNs surfaces. Afterward, the physicochemical and antibacterial activity of phage-engineered MBGNs was evaluated. The results showed that S. T phage PFPV25.1 was successfully bound onto MBGNs surfaces without losing their bioactivity. A higher quantity of phages could be bounded onto amine-functionalized MBGNs than onto non-functionalized MBGNs. Phages on amine-functionalized MBGNs exhibited higher antibacterial activity. The stability test showed that phages could remain on amine-functionalized MBGNs for over 28 days. This work provides valuable information on developing phage-modified MBGNs as a new and effective antibacterial system for biomedical applications.


Asunto(s)
Bacteriófagos , Nanopartículas , Dióxido de Silicio , Antibacterianos/farmacología , Aminas , Vidrio
5.
Neuron ; 111(24): 3988-4005.e11, 2023 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-37820724

RESUMEN

Fragile X messenger ribonucleoprotein 1 protein (FMRP) deficiency leads to fragile X syndrome (FXS), an autism spectrum disorder. The role of FMRP in prenatal human brain development remains unclear. Here, we show that FMRP is important for human and macaque prenatal brain development. Both FMRP-deficient neurons in human fetal cortical slices and FXS patient stem cell-derived neurons exhibit mitochondrial dysfunctions and hyperexcitability. Using multiomics analyses, we have identified both FMRP-bound mRNAs and FMRP-interacting proteins in human neurons and unveiled a previously unknown role of FMRP in regulating essential genes during human prenatal development. We demonstrate that FMRP interaction with CNOT1 maintains the levels of receptor for activated C kinase 1 (RACK1), a species-specific FMRP target. Genetic reduction of RACK1 leads to both mitochondrial dysfunctions and hyperexcitability, resembling FXS neurons. Finally, enhancing mitochondrial functions rescues deficits of FMRP-deficient cortical neurons during prenatal development, demonstrating targeting mitochondrial dysfunction as a potential treatment.


Asunto(s)
Trastorno del Espectro Autista , Síndrome del Cromosoma X Frágil , Enfermedades Mitocondriales , Humanos , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/genética , Trastorno del Espectro Autista/metabolismo , Neuronas/metabolismo , Neurogénesis , Enfermedades Mitocondriales/metabolismo , Receptores de Cinasa C Activada/genética , Receptores de Cinasa C Activada/metabolismo , Proteínas de Neoplasias/metabolismo , Factores de Transcripción/metabolismo
6.
ACS Appl Mater Interfaces ; 15(24): 29550-29560, 2023 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-37278380

RESUMEN

Exploring new approaches to realize the possibility of incorporating biologically active elements into mesoporous silicate bioactive glass nanoparticles (MBG NPs) and guaranteeing their meso- structural integrity and dimensional stability has become an attractive and interesting challenge in biomaterials science. We present a postgrafting strategy for introducing different metal elements into MBG NPs. This strategy is mediated by polydopamine (PDA) coating, achieving uniform loading of copper or copper-cobalt on the particles efficiently and ensuring the stability of MBG NPs in terms of particle size, mesoporous structure, and chemical structure. However, the PDA coating reduced the ion-binding free energy of the MBG NPs for calcium and phosphate ions, resulting in the deposition of minimal CaP clusters on the PDA@MBG NP surface when immersed for 7 days in simulated body fluid, indicating the absence of hydroxyapatite mineralization.


Asunto(s)
Cobre , Nanopartículas , Materiales Biocompatibles/farmacología , Vidrio/química , Nanopartículas/química , Porosidad , Silicatos
7.
JAMA Ophthalmol ; 141(5): e230405, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-37199808

RESUMEN

This case report discusses a diagnosis of 2 optic disc pits in an otherwise asymptomatic woman with high myopia.


Asunto(s)
Anomalías del Ojo , Miopía , Disco Óptico , Femenino , Humanos , Retina , Anomalías del Ojo/complicaciones , Anomalías del Ojo/diagnóstico , Miopía/complicaciones , Miopía/diagnóstico , Trastornos de la Visión , Pigmentación , Tomografía de Coherencia Óptica
8.
Bioact Mater ; 25: 239-255, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36817824

RESUMEN

Type II diabetes mellitus (TIIDM) remains a challenging clinical issue for both dentists and orthopedists. By virtue of persistent hyperglycemia and altered host metabolism, the pathologic diabetic micromilieu with chronic inflammation, advanced glycation end products accumulation, and attenuated biomineralization severely impairs bone regeneration efficiency. Aiming to "remodel" the pathologic diabetic micromilieu, we 3D-printed bioscaffolds composed of Sr-containing mesoporous bioactive glass nanoparticles (Sr-MBGNs) and gelatin methacrylate (GelMA). Sr-MBGNs act as a biomineralization precursor embedded in the GelMA-simulated extracellular matrix and release Sr, Ca, and Si ions enhancing osteogenic, angiogenic, and immunomodulatory properties. In addition to angiogenic and anti-inflammatory outcomes, this innovative design reveals that the nanocomposites can modulate extracellular matrix reconstruction and simulate biomineralization by activating lysyl oxidase to form healthy enzymatic crosslinked collagen, promoting cell focal adhesion, modulating osteoblast differentiation, and boosting the release of OCN, the noncollagenous proteins (intrafibrillar mineralization dependent), and thus orchestrating osteogenesis through the Kindlin-2/PTH1R/OCN axis. This 3D-printed bioscaffold provides a multifunctional biomineralization-inspired system that remodels the "barren" diabetic microenvironment and sheds light on the new bone regeneration approaches for TIIDM.

9.
Environ Pollut ; 316(Pt 1): 120546, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36332704

RESUMEN

Microplastic and antibiotic contamination are considered an increasing environmental problem in aquatic systems, while little is known about the impact of microplastics and co-pollutant with antibiotics on freshwater vascular plants, particularly the effects of interactions between macrophytes. Here, we performed a mesocosm experiment to evaluate the impact of polyethylene-microplastics and their co-pollutants with ciprofloxacin on the growth and physiological characteristics of Spirodela polyrhiza and Lemna minor and the interactions between these two macrophytes. Our results showed that microplastics alone cannot significantly influence fresh weight and specific leaf area of the two test free-floating macrophytes, but the effects on photosynthetic pigments, malondialdehyde, catalase and soluble sugar contents were species-specific. Ciprofloxacin can significant adverse effects on the growth and physiological traits of the two test macrophytes and microplastic mitigated the toxicity of ciprofloxacin on the two free-floating plants to a certain extent. In addition, our studies showed that microplastics and co-pollutants can influence relative yield and competitiveness of S. polyrhiza and L. minor by directly or indirectly influencing their physiology and growth. Therefore our findings suggest that species-specific sensibility to microplastic and its co-pollutant among free-floating macrophytes may influence macrophyte population dynamics and thereby community structure and ecosystem functioning. And microplastics altered other contaminant behaviours and toxicity, and may directly or indirectly influence macrophytes interactions and community structure. The present study is the first experimental study exploring the effects of microplastics alone and with their co-pollutants on interactions between free-floating macrophytes, which can provide basic theoretical guidance for improving the stability of freshwater ecosystems.


Asunto(s)
Araceae , Contaminantes Ambientales , Contaminantes Químicos del Agua , Microplásticos , Plásticos/farmacología , Ecosistema , Ciprofloxacina/toxicidad , Contaminantes Ambientales/farmacología , Contaminantes Químicos del Agua/análisis
10.
IEEE J Biomed Health Inform ; 27(5): 2334-2344, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-34788225

RESUMEN

With the application of wireless sensor network (WSN) in healthcare field, online sharing of medical data has attracted more and more attention. However, wearable sensor nodes are limited in energy, storage space and data processing capacity, which largely restricts their deployment in resource demand application scenarios. Fortunately, cloud storage services can enrich the capabilities of wearable sensors and provide an effective method for people to share data within a group. However, as medical data directly relates to patients' health and privacy information, ensuring the integrity and privacy of medical records stored in cloud servers becomes a key issue to be urgently solved. Many public data auditing schemes have been put forward to address the above issues. Unfortunately, most of them have security vulnerabilities or poor functionality and performance. In this paper, we come up with a secure and efficient certificateless public auditing scheme for cloud-assisted medical WSNs, which not only supports dynamic data sharingand privacy protection, but also achieves efficient group user revocation. Security analysis and performance evaluation demonstrate that our scheme significantly reduce the total computation cost while achieving a higher security level. Compared with other related schemes, our new proposal is more suitable for group user data sharing in cloud-assisted medical WSNs.


Asunto(s)
Registros Médicos , Privacidad , Humanos , Seguridad Computacional , Nube Computacional , Confidencialidad
11.
J Ophthalmol ; 2022: 3259453, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36276919

RESUMEN

Background: Complement 3 (C3) is the crucial component of the complement cascade when retina was exposed to external stimulus. Cellular communication network 2/connective tissue growth factor (CCN2/CTGF) is important in response of retinal stress and a fulcrum for angiogenesis and fibrosis scar formation. Our study aims to explore the interaction between C3 and CCN2/CTGF via bioinformatics analyses and in vitro cell experiments. Methods: The GSE dataset was selected to analyse the chemokine expression in human retinal pigment epithelium (ARPE-19) cells under stimulus. Then, RPE cells were further transfected with or without C3 siRNA, followed by C3a (0.1 µM or 0.3 µM) for 24, 48, and 72 hours. Reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to measure CCN2/CTGF mRNA and protein levels. Results: The GSE36331 revealed C3 expression was significantly elevated in RPE under stimulus. Compared with negative control, CCN2/CTGF mRNA was increased with all types of C3a treatments, whereas a significant increase of protein level was only observed with high concentration of 0.3 µM C3a for a prolonged 72-hour time. Compared with nontransfected cells, significant reductions of CCN2/CTGF mRNA were observed in the C3 siRNA transfected cells with 0.3 µM C3a for 24, 48, and 72 hours, and a significant reduction of CCN2/CTGF protein was observed with 0.3 µM C3a for 48 hours. Conclusions: C3 was elevated in RPE under environmental stimulus and long-term exposure to specified concentration of C3a increased CCN2/CTGF expression in RPE, which could be partially reversed by C3 siRNA.

12.
IEEE J Biomed Health Inform ; 26(8): 4111-4122, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35503853

RESUMEN

This paper tackles automated categorization of Age-related Macular Degeneration (AMD), a common macular disease among people over 50. Previous research efforts mainly focus on AMD categorization with a single-modal input, let it be a color fundus photograph (CFP) or an OCT B-scan image. By contrast, we consider AMD categorization given a multi-modal input, a direction that is clinically meaningful yet mostly unexplored. Contrary to the prior art that takes a traditional approach of feature extraction plus classifier training that cannot be jointly optimized, we opt for end-to-end multi-modal Convolutional Neural Networks (MM-CNN). Our MM-CNN is instantiated by a two-stream CNN, with spatially-invariant fusion to combine information from the CFP and OCT streams. In order to visually interpret the contribution of the individual modalities to the final prediction, we extend the class activation mapping (CAM) technique to the multi-modal scenario. For effective training of MM-CNN, we develop two data augmentation methods. One is GAN-based CFP/OCT image synthesis, with our novel use of CAMs as conditional input of a high-resolution image-to-image translation GAN. The other method is Loose Pairing, which pairs a CFP image and an OCT image on the basis of their classes instead of eye identities. Experiments on a clinical dataset consisting of 1,094 CFP images and 1,289 OCT images acquired from 1,093 distinct eyes show that the proposed solution obtains better F1 and Accuracy than multiple baselines for multi-modal AMD categorization. Code and data are available at https://github.com/li-xirong/mmc-amd.


Asunto(s)
Degeneración Macular , Técnicas de Diagnóstico Oftalmológico , Humanos , Degeneración Macular/diagnóstico por imagen , Redes Neurales de la Computación , Fotograbar , Reproducibilidad de los Resultados , Tomografía de Coherencia Óptica/métodos
13.
Ann Transl Med ; 10(6): 316, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35434041

RESUMEN

Background: Functional constipation (FC) is a common gastrointestinal (GI) disorder characterized by symptoms of constipation without a clear physiologic or anatomic cause. Gut microbiome dysbiosis has been postulated to be a factor in the development of FC, and treatment with probiotic regimens, including strains of Lactobacillus plantarum (L. plantarum), has demonstrated efficacy in managing symptoms. To further understand the role of L. plantarum in GI health, we conducted an animal study and a randomized, double-blind, placebo-controlled clinical trial to evaluate the effect of a specific sub-strain, Lp3a, on FC. Methods: For the animal study, male Kunming mice were treated with doses of L. plantarum Lp3a ranging from 0.67 to 2.00 g/kg or an equivalent amount of placebo for 15 days prior to the induction of constipation via 20 mL/kg of 25% diphenoxylate solution. GI motility parameters including intestinal motion and stool amount were then assessed. In the human study, 120 patients with FC were randomized to treatment [L. plantarum Lp3a; 2×1.0×1010 (colony forming units; CFU) ×7 days] or control groups (n=60 each). The primary endpoint was survey information on FC signs/symptoms. Participants and observers were blinded to group allocation. A subset of 20 Lp3a treated patients underwent pre- and post-treatment 16 s ribosomal ribonucleic acid (rRNA) gene sequencing. Whole genome sequencing (WGS) of L. plantarum Lp3a was also performed. Results: Lp3a-treated mice showed significantly improved intestinal motion, reduced time to first defecation, and increased stool amounts. Similarly, patients in the treatment group (n=59) reported significant improvements in FC signs/symptoms compared to controls (n=58; all P<0.05). Although 16 s rRNA sequencing revealed no significant variations between pre- and post-treatment samples, WGS of Lp3a itself revealed several biological pathways that may underlie the relief of FC symptoms in animals and humans, including methane and fatty acid metabolism and bile acid biosynthesis. Conclusions: We found that the use of the novel probiotic sub-strain, L. plantarum Lp3a, led to clinically significant improvements in FC in both mice and humans, and identified the potential biological mechanisms underlying this activity.

14.
Proc Natl Acad Sci U S A ; 118(34)2021 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-34417306

RESUMEN

In this study, we use molecular genetic approaches to clarify the role of the Hedgehog (Hh) pathway in regulating the blood-brain/spinal cord barrier (BBB) in the adult mouse central nervous system (CNS). Our work confirms and extends prior studies to demonstrate that astrocytes are the predominant cell type in the adult CNS that transduce Hh signaling, revealed by the expression of Gli1, a target gene of the canonical pathway that is activated in cells receiving Hh, and other key pathway transduction components. Gli1+ (Hh-responsive) astrocytes are distributed in specific regions of the CNS parenchyma, including layers 4/5/6 of the neocortex, hypothalamus, thalamus, and spinal cord, among others. Notably, although BBB properties in endothelial cells are normally regulated by both paracellular and transcellular mechanisms, conditional inactivation of Hh signaling in astrocytes results in transient, region-specific BBB defects that affect transcytosis but not paracellular diffusion. These findings stand in contrast to prior studies that implicated astrocytes as a source of Sonic hedgehog that limited extravasation via both mechanisms [J. I. Alvarez et al., Science 334, 1727-1731 (2011)]. Furthermore, using three distinct Cre driver lines as well as pharmacological approaches to inactivate Hh-pathway transduction globally in CNS astrocytes, we find that these specific BBB defects are only detected in the rostral hypothalamus and spinal cord but not the cortex or other regions where Gli1+ astrocytes are found. Together, our data show that Gli1+ Hh-responsive astrocytes have regionally distinct molecular and functional properties and that the pathway is required to maintain BBB properties in specific regions of the adult mammalian CNS.


Asunto(s)
Astrocitos/metabolismo , Barrera Hematoencefálica/metabolismo , Proteínas Hedgehog/metabolismo , Tamoxifeno/farmacología , Animales , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Gliosis/metabolismo , Proteínas Hedgehog/genética , Ratones , Ratones Transgénicos , Moduladores Selectivos de los Receptores de Estrógeno/farmacología , Receptor Smoothened/genética , Receptor Smoothened/metabolismo , Médula Espinal/efectos de los fármacos , Alcaloides de Veratrum/farmacología
15.
Int J Nanomedicine ; 16: 3201-3216, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34007174

RESUMEN

PURPOSE: Polyetheretherketone (PEEK) exhibits high mechanical strengths and outstanding biocompatibility but biological inertness that does not excite the cell responses and stimulate bone formation. The objective of this study was to construct submicro-nano structures on PEEK by femtosecond laser (FSL) for exciting the responses of MC3T3-E1 cells and gingival epithelial (GE) cells, which induce regeneration of bone/gingival tissues for long-term stability of dental implants. MATERIALS AND METHODS: In this study, submicro-nano structures were created on PEEK surface by FSL with power of 80 mW (80FPK) and 160 mW (160FPK). RESULTS: Compared with PEEK, both 80FPK and 160FPK with submicro-nano structures exhibited elevated surface performances (hydrophilicity, surface energy, roughness and protein absorption). Furthermore, in comparison with 80FPK, 160FPK further enhanced the surface performances. In addition, compared with PEEK, both 80FPK and 160FPK significantly excited not only the responses (adhesion, proliferation, alkaline phosphatase [ALP] activity and osteogenic gene expression) of MC3T3-E1 cells but also responses (adhesion as well as proliferation) of GE cells of human in vitro. Moreover, in comparison with 80FPK, 160FPK further enhanced the responses of MC3T3-E1 cells/GE cells. CONCLUSION: FSL created submicro-nano structures on PEEK with elevated surface performances, which played crucial roles in exciting the responses of MC3T3-E1 cells/GE cells. Consequently, 160FPK with elevated surface performances and outstanding cytocompatibility would have enormous potential as an implant for dental replacement.


Asunto(s)
Células Epiteliales/citología , Células Epiteliales/efectos de la radiación , Encía/citología , Cetonas/química , Rayos Láser , Nanoestructuras/química , Tamaño de la Partícula , Polietilenglicoles/química , Adsorción , Fosfatasa Alcalina/metabolismo , Animales , Benzofenonas , Adhesión Celular , Línea Celular , Proliferación Celular , Forma de la Célula , Células Epiteliales/ultraestructura , Regulación de la Expresión Génica , Humanos , Microscopía de Fuerza Atómica , Osteogénesis/genética , Espectroscopía de Fotoelectrones , Polímeros , Propiedades de Superficie , Agua/química
16.
Ecol Evol ; 11(7): 3110-3119, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33841771

RESUMEN

Analysis of stable isotope composition is an important tool in research on plant physiological ecology. However, large-scale patterns of leaf-stable isotopes for aquatic macrophytes have received considerably less attention. In this study, we examined the spatial pattern of stable isotopes of carbon (δ13C) and nitrogen (δ15N) of macrophytes leaves collected across the arid zone of northwestern China (approximately 2.4 × 106 km2) and attempted to illustrate its relationship with environmental factors (i.e., temperature, precipitation, potential evapotranspiration, sediment total carbon and nitrogen). Our results showed that the mean values of the leaf δ13C and δ15N in the macrophytes sampled from the arid zone were -24.49‰ and 6.82‰, respectively, which were far less depleted than those measured of terrestrial plants. The order of averaged leaf δ13C from different life forms was as follows: submerged > floating-leaved > emergent. Additionally, our studies indicated that the values of foliar δ13C values of all the aquatic macrophytes were only negatively associated with precipitation, but the foliar δ15N values were mainly associated with temperature, precipitation, and potential evapotranspiration. Therefore, we speculated that water-relation factors are the leaf δ13C determinant of macrophytes in the arid zone of northwestern China, and the main factors affecting leaf δ15N values are the complex combination of water and energy factors.

17.
Environ Sci Technol ; 55(8): 5272-5281, 2021 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-33764736

RESUMEN

In addition to a rise in global air and water mean temperatures, extreme climate events such as heat waves are increasing in frequency, intensity, and duration in many regions of the globe. Developing a mechanistic understanding of the impacts of heat waves on key ecosystem processes and how they differ from just an increase in mean temperatures is therefore of utmost importance for adaptive management against effects of global change. However, little is known about the impact of extreme events on freshwater ecosystem processes, particularly the decomposition of macrophyte detritus. We performed a mesocosm experiment to evaluate the impact of warming and heat waves on macrophyte detrital decomposition, applied as a fixed increment (+4 °C) above ambient and a fluctuating treatment with similar energy input, ranging from 0 to 6 °C above ambient (i.e., simulating heat waves). We showed that both warming and heat waves significantly accelerate dry mass loss of the detritus and carbon (C) release but found no significant differences between the two heated treatments on the effects on detritus dry mass loss and C release amount. This suggests that moderate warming indirectly enhanced macrophyte detritus dry mass loss and C release mainly by the amount of energy input rather than by the way in which warming was provided (i.e., by a fixed increment or in heat waves). However, we found significantly different amounts of nitrogen (N) and phosphorus (P) released between the two warming treatments, and there was an asymmetric response of N and P release patterns to the two warming treatments, possibly due to species-specific responses of decomposers to short-term temperature fluctuations and litter quality. Our results conclude that future climate scenarios can significantly accelerate organic matter decomposition and C, N, and P release from decaying macrophytes, and more importantly, there are asymmetric alterations in macrophyte-derived detrital N and P release dynamic. Therefore, future climate change scenarios could lead to alterations in N/P ratios in the water column via macrophyte decomposition processes and ultimately affect the structure and function of aquatic ecosystems, especially in the plankton community.


Asunto(s)
Ecosistema , Calor , Cambio Climático , Agua Dulce , Nitrógeno , Nutrientes
18.
Int J Nanomedicine ; 16: 725-740, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33542627

RESUMEN

PURPOSE: As a dental material, polyetheretherketone (PEEK) is bioinert that does not induce cellular response and bone/gingival tissues regeneration. This study was to develop bioactive coating on PEEK and investigate the effects of coating on cellular response. MATERIALS AND METHODS: Tantalum pentoxide (TP) coating was fabricated on PEEK surface by vacuum evaporation and responses of rat bone marrow mesenchymal stem (RBMS) cells/human gingival epithelial (HGE) were studied. RESULTS: A dense coating (around 400 nm in thickness) of TP was closely combined with PEEK (PKTP). Moreover, the coating was non-crystalline TP, which contained many small humps (around 10 nm in size), exhibiting a nanostructured surface. In addition, the roughness, hydrophilicity, surface energy, and protein adsorption of PKTP were remarkably higher than that of PEEK. Furthermore, the responses (adhesion, proliferation, and osteogenic gene expression) of RBMS cells, and responses (adhesion and proliferation) of HGE cells to PKTP were remarkably improved in comparison with PEEK. It could be suggested that the nanostructured coating of TP on PEEK played crucial roles in inducing the responses of RBMS/HGE cells. CONCLUSION: PKTP with elevated surface performances and outstanding cytocompatibility might have enormous potential for dental implant application.


Asunto(s)
Células Epiteliales/citología , Encía/citología , Cetonas/farmacología , Células Madre Mesenquimatosas/citología , Nanoestructuras/química , Óxidos/farmacología , Polietilenglicoles/farmacología , Tantalio/farmacología , Adsorción , Fosfatasa Alcalina/metabolismo , Animales , Benzofenonas , Adhesión Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Células Epiteliales/ultraestructura , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Masculino , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/enzimología , Nanoestructuras/ultraestructura , Osteogénesis/efectos de los fármacos , Osteogénesis/genética , Polímeros , Ratas Sprague-Dawley , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Difracción de Rayos X
19.
Br J Ophthalmol ; 105(4): 561-566, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-32499330

RESUMEN

AIMS: To investigate the efficacy of a bi-modality deep convolutional neural network (DCNN) framework to categorise age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) from colour fundus images and optical coherence tomography (OCT) images. METHODS: A retrospective cross-sectional study was proposed of patients with AMD or PCV who came to Peking Union Medical College Hospital. Diagnoses of all patients were confirmed by two retinal experts based on diagnostic gold standard for AMD and PCV. Patients with concurrent retinal vascular diseases were excluded. Colour fundus images and spectral domain OCT images were taken from dilated eyes of patients and healthy controls, and anonymised. All images were pre-labelled into normal, dry or wet AMD or PCV. ResNet-50 models were used as the backbone and alternate machine learning models including random forest classifiers were constructed for further comparison. For human-machine comparison, the same testing data set was diagnosed by three retinal experts independently. All images from the same participant were presented only within a single partition subset. RESULTS: On a test set of 143 fundus and OCT image pairs from 80 eyes (20 eyes per-group), the bi-modal DCNN demonstrated the best performance, with accuracy 87.4%, sensitivity 88.8% and specificity 95.6%, and a perfect agreement with diagnostic gold standard (Cohen's κ 0.828), exceeds slightly over the best expert (Human1, Cohen's κ 0.810). For recognising PCV, the model outperformed the best expert as well. CONCLUSION: A bi-modal DCNN for automated classification of AMD and PCV is accurate and promising in the realm of public health.


Asunto(s)
Enfermedades de la Coroides/diagnóstico , Coroides/irrigación sanguínea , Angiografía con Fluoresceína/métodos , Redes Neurales de la Computación , Pólipos/diagnóstico , Tomografía de Coherencia Óptica/métodos , Degeneración Macular Húmeda/diagnóstico , Estudios Transversales , Fondo de Ojo , Humanos , Estudios Retrospectivos , Agudeza Visual
20.
Indian Pediatr ; 57(9): 815-819, 2020 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-32999110

RESUMEN

OBJECTIVE: To assess the effects of delayed cord clamping (DCC) on hemoglobin (Hb), mean corpuscular volume (MCV) and ferritin level in infants 2 months or older. EVIDENCE ACQUISITION: Meta-analysis of randomized control trials searched systematically from PubMed, Cochrane and Web of science. Trials published from Jan 1,1975 to Mar 12, 2018, no language and country restrictions. Twelve studies were included in this meta-analysis. In total, 993 infants were treated with DCC, while 989 cases received early cord clamping. Delayed cord clamping was defined as umbilical cord clamping time greater than 60s after delivery. Outcomes assed were (i) hemoglobin (Hb), (ii) mean corpuscular volume (MCV) and ferritin level. RESULTS: The results show that DCC increased hemoglobin level (SMD=0.4678 95%CI: [0.1515, 0.7841]), Ferritin level (SMD=2.1450 95%CI: [1.0431, 3.2470]) and MCV (SMD=0.5751 95%CI: [0.1637, 0.9865]) in infants between 2-12 months compared to ECC subject analysis noted the effects of Hb increase was greater in Asian infants. CONCLUSIONS: Delayed cord clamping improved the Hb, MCV and ferritin level of infants after birth.


Asunto(s)
Anemia , Cordón Umbilical , Constricción , Parto Obstétrico , Femenino , Humanos , Lactante , Embarazo , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...