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1.
Front Pharmacol ; 15: 1281095, 2024.
Article in English | MEDLINE | ID: mdl-39011501

ABSTRACT

Background and Aims: Metabolic dysfunction-associated steatotic liver disease (MASLD) poses a considerable health risk. Nevertheless, its risk factors are not thoroughly comprehended, and the association between the reticulocyte count and MASLD remains uncertain. This study aimed to explore the relationship between reticulocyte count and MASLD. Methods: A total of 310,091 individuals from the UK Biobank were included in this cross-sectional study, and 7,316 individuals were included in this prospective study. The cross-sectional analysis categorized reticulocyte count into quartiles, considering the sample distribution. Logistic regression models examined the connection between reticulocyte count and MASLD. In the prospective analysis, Cox analysis was utilized to investigate the association. Results: Our study findings indicate a significant association between higher reticulocyte count and an elevated risk of MASLD in both the cross-sectional and prospective analyses. In the cross-sectional analysis, the adjusted odds ratios (ORs) of MASLD increased stepwise over reticulocyte count quartiles (quartile 2: OR 1.22, 95% CI 1.17-1.28, p < 0.001; quartile 3: OR 1.44; 95% CI 1.38-1.51, p < 0.001; quartile 4: OR 1.66, 95% CI 1.59-1.74, p < 0.001). The results of prospective analyses were similar. Conclusion: Increased reticulocyte count was independently associated with a higher risk of MASLD. This discovery offers new insights into the potential of reticulocytes as biomarkers for MASLD.

2.
Genet Epidemiol ; 47(4): 332-357, 2023 06.
Article in English | MEDLINE | ID: mdl-36808763

ABSTRACT

Mendelian randomization is a statistical method for inferring the causal relationship between exposures and outcomes using an economics-derived instrumental variable approach. The research results are relatively complete when both exposures and outcomes are continuous variables. However, due to the noncollapsing nature of the logistic model, the existing methods inherited from the linear model for exploring binary outcome cannot take the effect of confounding factors into account, which leads to biased estimate of the causal effect. In this article, we propose an integrated likelihood method MR-BOIL to investigate causal relationships for binary outcomes by treating confounders as latent variables in one-sample Mendelian randomization. Under the assumption of a joint normal distribution of the confounders, we use expectation maximization algorithm to estimate the causal effect. Extensive simulations demonstrate that the estimator of MR-BOIL is asymptotically unbiased and that our method improves statistical power without inflating type I error rate. We then apply this method to analyze the data from Atherosclerosis Risk in Communications Study. The results show that MR-BOIL can better identify plausible causal relationships with high reliability, compared with the unreliable results of existing methods. MR-BOIL is implemented in R and the corresponding R code is provided for free download.


Subject(s)
Mendelian Randomization Analysis , Models, Genetic , Humans , Likelihood Functions , Mendelian Randomization Analysis/methods , Reproducibility of Results , Causality
3.
Materials (Basel) ; 14(10)2021 May 13.
Article in English | MEDLINE | ID: mdl-34068429

ABSTRACT

Electric field-assisted sintering has ubiquitous merits over conventional sintering technology for the fabrication of difficult-to-deform materials. To investigate the effect of sintering pressure and temperature on the densification of Inconel 718 superalloy, a numerical simulation model was established based on the Fleck-Kuhn-McMeeking (FKM) and Gurson-Tvergaard-Needleman (GTN) models, which covers a wide range of porosity. At a sintering pressure below 50 MPa or a sintering temperature below 950 °C, the average porosity of the sintered superalloy is over 0.17 with low densification. Under a pressure above 110 MPa and a temperature above 1250 °C, the sintered superalloy quickly completes densification and enters the plastic yield stage, making it difficult to control the sintering process. When the pressure is above 70 MPa while the temperature exceeds 1150 °C, the average porosity is 0.11, with little fall when the pressure or temperature rises. The experimental results indicated that the relative density of the sintered superalloy under 70 MPa and 1150 °C is 94.46%, and the proportion of the grain size below 10 µm is 73%. In addition, the yield strength of the sintered sample is 512 MPa, the compressive strength comes to 1260 MPa when the strain is over 0.8, and the microhardness is 395 Hv, demonstrating a better mechanical property than the conventional superalloy.

4.
Sensors (Basel) ; 21(7)2021 Mar 31.
Article in English | MEDLINE | ID: mdl-33807129

ABSTRACT

This paper is concerned with relative localization-based optimal area coverage placement using multiple unmanned aerial vehicles (UAVs). It is assumed that only one of the UAVs has its global position information before performing the area coverage task and that ranging measurements can be obtained among the UAVs by using ultra-wide band (UWB) sensors. In this case, multi-UAV relative localization and cooperative coverage control have to be run simultaneously, which is a quite challenging task. In this paper, we propose a single-landmark-based relative localization algorithm, combined with a distributed coverage control law. At the same time, the optimal multi-UAV placement problem was formulated as a quadratic programming problem by compromising between optimal relative localization and optimal coverage control and was solved by using Sequential Quadratic Programming (SQP) algorithms. Simulation results show that our proposed method can guarantee that a team of UAVs can efficiently localize themselves in a cooperative manner and, at the same time, complete the area coverage task.

5.
RSC Adv ; 8(28): 15740-15753, 2018 Apr 23.
Article in English | MEDLINE | ID: mdl-35539468

ABSTRACT

Functional polymer brush modified graphene oxide (FPGO) with functional linear polysiloxane brushes was synthesized via surface precipitation polymerization (sol-gel) and chemical modification. Then, FPGO was covalently cross-linked to the sulfonated polysulfone (SPSU) matrix to obtain novel SPSU/FPGO cross-linked nanocomposite membranes. Meanwhile, SPSU/GO composite membranes and a pristine SPSU membrane were fabricated as control groups. Reduced agglomeration of the inorganic filler and better interfacial interaction, which are benefit to increase diffusion resistance of methanol and to generate continuous channels for fast proton transportation at elevated temperature, were observed in SPSU/FPGO cross-linked membranes. Moreover, the enhanced membrane stability (thermal, oxidative and dimensional stability) and good mechanical performance also guaranteed their proton conducting durability. It is noteworthy that the SPSU/FPGO-1 cross-linked membrane possesses the best comprehensive properties among all the prepared membranes and Nafion®117, it acquires the highest proton conductivity of 0.462 S cm-1 at 90 °C under hydrated conditions together with a low methanol permeability of 1.71 × 10-6 cm2 s-1 at 30 °C. The resulting high membrane selectivity displays the great potential of the SPSU/FPGO cross-linked membrane for DMFCs application.

6.
Mater Sci Eng C Mater Biol Appl ; 74: 230-237, 2017 May 01.
Article in English | MEDLINE | ID: mdl-28254289

ABSTRACT

Spinal cord injury (SCI) is a severe trauma for which no effective treatment is currently available. In this study, a composited treatment system was prepared using a silk fibroin/alginates/glial cell line-derived neurotrophic factor (SF/AGs/GDNF) scaffold seeded with human umbilical cord mesenchymal stem cells (hUCMSCs) and the combined therapeutic effects of the composite scaffold to repair SCI rats were evaluated. The use of SF as a scaffold material could act as a biomimetic platform allowing neurons to properly accommodate and rebuild the target tissue. The SF/AGs/GDNF scaffold had the best sustained-release function and the AGs were the key determining factor in the controlled release of GDNF. After 8weeks of treatment, the hUCMSCs on SF/AGs/GDNF composite scaffolds could significantly enhance the scar expansion of spinal cord tissue and increased the number of surviving neurons. The combination of GDNF and hUCMSCs transplantation loaded on SF/AGs composite scaffolds exhibited better therapeutic and repair effects to the SCI of rats, compared with the SF/AGs group or GDNF alone on SF/AGs scaffolds. The composite scaffold, GDNF and stem cells could build a bioactive material to form the micro-environment of growth and repair of the neurons. These results may provide a theoretical basis and beneficial exploration for clinical treatment of SCI.


Subject(s)
Alginates/chemistry , Glial Cell Line-Derived Neurotrophic Factor/chemistry , Mesenchymal Stem Cell Transplantation , Spinal Cord Injuries/therapy , Tissue Scaffolds/chemistry , Animals , Behavior, Animal , Cell Proliferation , Cells, Cultured , Female , Glial Cell Line-Derived Neurotrophic Factor/metabolism , Humans , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism , Microscopy, Fluorescence , PC12 Cells , Rats , Rats, Wistar , Spinal Cord Injuries/metabolism , Spinal Cord Injuries/pathology , Umbilical Cord/cytology
7.
Nan Fang Yi Ke Da Xue Xue Bao ; 36(7): 1024-8, 2016 Jun 20.
Article in Chinese | MEDLINE | ID: mdl-27435789

ABSTRACT

OBJECTIVE: To prepare a drug-loading film using chitosan and carboxymethyl chitosan as the carrier materials for delivering matrine to oral ulcers. METHODS: Matrine-loading films using chitosan or carboxymethyl chitosan as the carrier materials were prepared by solution casting method and orthogonal experiment at room temperature. The mechanical properties, surface morphology and drug-loading capacity of the drug-loading film were characterized using tensile test, scanning electron microscopy (SEM), swelling test and in vitro drug release test. RESULTS: When the molecular weight of chitosan was 650 000 and the mass ratio of chitosan/glycerol was 1:1.4, the prepared film had the maximum mechanical strength and tensile modulus reaching 0.7875 MPa. SEM observation showed that matrine aggregated at the bottom of the drug-loading film with an asymmetrical distribution. The in vitro drug release test showed that the film had a high drug-loading capacity and a sustained drug release property. The duration of drug release from the drug-loading film was prolonged as the molecular weight of chitosan increased, reaching 23 h when the molecular weight of chitosan was 650 000. The duration of drug release was further increased to 108 h when the bottom of the drug-loading film was coated with a layer of 1% carboxymethyl chitosan. CONCLUSION: The matrix materials of the drug-loading film are natural, green, nontoxic and biodegradable, and the preparation of the film is simple without using large quantities of organic solvents. The novel drug-loading film can obviously prolong the duration of drugs release for better local drug delivery to oral ulcers in a sustained manner.


Subject(s)
Alkaloids/chemistry , Chitosan/analogs & derivatives , Drug Delivery Systems , Drug Liberation , Glycerol/chemistry , Quinolizines/chemistry , Chitosan/chemistry , Delayed-Action Preparations , Microscopy, Electron, Scanning , Matrines
8.
Mol Med Rep ; 12(5): 7011-6, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26323253

ABSTRACT

Oxidative stress can alter the expression level of microRNAs (miRNAs) and has a role in oxidative damage generated by reactive oxygen species (ROS). While previous studies have demonstrated that miR­146a, miR­21 and miR­150 are essential for ROS production in heart disease, the role of these miRNAs in spinal cord injuries has not yet been examined. The present study focused on examining the role of miR­146a, miR­21 and miR­150 during H2O2 stimulation in rat neuronal spinal cord (RN­sc) cells. RN­sc cells were treated with H2O2, and cells were harvested for reverse transcription quantitative polymerase chain reaction (RT­qPCR) to detect the expression levels of miR­146a, miR­21 and miR­150. The results demonstrated that miR­146a, miR­21 and miR­150 expression was upregulated during H2O2 treatment. T-cell death and apoptosis were investigated using an MTT assay and flow cytometric analysis, respectively. Following miR­21 silencing, H2O2­induced cell death and apoptosis were reduced in RN­sc cells, while miR­150 silencing had no effect. Furthermore, Smad7 was identified as a direct target of miR­21 using a Luciferase reporter assay, RT-qPCR and western blot analysis. In addition, while H2O2 downregulated Smad7 protein expression, this was reversed by inhibiting miR­21 expression. Based on previous studies, it was predicted that miR­21 has a role in ROS production through regulating Smad7 in rat spinal cord neurons.


Subject(s)
Apoptosis/drug effects , Cell Proliferation/drug effects , Hydrogen Peroxide/toxicity , MicroRNAs/metabolism , Neurons/drug effects , 3' Untranslated Regions , Animals , Base Sequence , Cells, Cultured , Neurons/cytology , Neurons/metabolism , Rats , Reactive Oxygen Species/metabolism , Real-Time Polymerase Chain Reaction , Sequence Alignment , Smad7 Protein/antagonists & inhibitors , Smad7 Protein/genetics , Smad7 Protein/metabolism , Spinal Cord/cytology , Up-Regulation/drug effects
9.
J Mech Behav Biomed Mater ; 20: 347-53, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23453826

ABSTRACT

A novel polydimethylsiloxane/liquid crystal cross-linked membrane (PDMS/LC) was prepared by using PDMS containing vinyl groups and LCs containing unsaturated linkages as matrix materials. Mechanical properties, liquid crystalline performance and blood compatibility of the PDMS/LC cross-linked membrane containing different LC contents and LC groups were investigated, respectively. The results showed that mechanical properties of the membrane increased more significantly than those of pure PDMS membranes. The PDMS/LC cross-linked membrane also possessed better membrane-forming ability, lower hemolysis rate, less platelets adhesion and more favorable anti-coagulant properties. Additionally, mechanical properties and blood compatibility of the membrane can be enhanced simultaneously and obviously due to the introduction of the cholesteric liquid crystals and the application of the preferred cross-linked reaction without byproducts.


Subject(s)
Blood Coagulation/drug effects , Dimethylpolysiloxanes/chemistry , Dimethylpolysiloxanes/pharmacology , Liquid Crystals/chemistry , Membranes, Artificial , Biocompatible Materials/chemical synthesis , Biocompatible Materials/pharmacology , Cross-Linking Reagents/chemistry , Elastic Modulus , Humans , Materials Testing , Refractometry , Surface Tension , Tensile Strength
10.
Adv Drug Deliv Rev ; 60(15): 1650-62, 2008 Dec 14.
Article in English | MEDLINE | ID: mdl-18848591

ABSTRACT

Natural polysaccharides, due to their outstanding merits, have received more and more attention in the field of drug delivery systems. In particular, polysaccharides seem to be the most promising materials in the preparation of nanometeric carriers. This review relates to the newest developments in the preparation of polysaccharides-based nanoparticles. In this review, four mechanisms are introduced to prepare polysaccharides-based nanoparticles, that is, covalent crosslinking, ionic crosslinking, polyelectrolyte complex, and the self-assembly of hydrophobically modified polysaccharides.


Subject(s)
Drug Delivery Systems , Nanoparticles , Polysaccharides/chemistry , Animals , Cross-Linking Reagents/chemistry , Electrolytes/chemistry , Humans , Hydrophobic and Hydrophilic Interactions
11.
J Biomed Mater Res A ; 83(4): 1110-1116, 2007 Dec 15.
Article in English | MEDLINE | ID: mdl-17584905

ABSTRACT

Surface modification of biomaterials has been adopted over the years to improve their biocompatibility. In this study, aiming to promote hydrophilicity and to introduce natural recognition sites onto poly(L-lactic acid) (PLLA) films, chitosan and its derivatives, carboxymethyl chitosan (CMC) and N-methylene phosphonic chitosan (NPC), were used to modify the surface of PLLA films by an entrapment method. The surface properties of original and modified PLLA films were measured by using water contact angle measurement and X-ray photoelectron spectroscopy (XPS). Subsequently, the cytocompatibility of these PLLA films was investigated by testing osteoblasts-like cytocompatibility, cell attachment, cell proliferation, alkaline phosphatase activity, and cell cycle. Experimental results indicated that the hydrophilicity of the modified films was improved and the surface of the modified PLLA films became enriched with chitosan and its derivatives. Moreover, the surface modification with chitosan and its derivatives significantly promoted osteoblasts-like compatibility of PLLA films. This surface modification, combining the individual advantages of PLLA with good mechanical property and chitosan as well as its derivatives with good cytocompatibility, is a promising method to prepare desirable biomaterials.


Subject(s)
Chitosan/chemistry , Lactic Acid/chemistry , Osteoblasts/cytology , Polymers/chemistry , Alkaline Phosphatase/metabolism , Animals , Cell Adhesion , Cell Cycle , Cell Proliferation , Cells, Cultured , Osteoblasts/enzymology , Polyesters , Rats , Rats, Sprague-Dawley , Surface Properties
12.
J Biomed Mater Res A ; 83(3): 806-12, 2007 Dec 01.
Article in English | MEDLINE | ID: mdl-17559117

ABSTRACT

In this study, novel nanoparticles were prepared by polyelectrolyte complexation between heparin and chitosan on simple and mild conditions. The size, polydispersity, zeta potential, and morphology of the nanoparticles were characterized. Entrapment studies of the nanoparticles were conducted using bovine serum albumin (BSA) as a model protein. Specifically, the effects of the pH value of chitosan solution, chitosan molecular weight (MW), chitosan concentration, heparin concentration, and BSA concentration on the nanoparticle size, the nanoparticle yield, and BSA entrapment were studied in detail. We found that, the size and the yield of the nanoparticles were affected by the above factors. The nanoparticle yield played a crucial role in BSA entrapment, namely, more nanoparticles could encapsulate more BSA. At length, suitably high pH value of chitosan solution, moderate chitosan MW, increasing both heparin concentration and chitosan concentration at an optimal concentration ratio favored more nanoparticles formed and consequently a higher BSA entrapment efficiency.


Subject(s)
Chitosan/chemistry , Heparin/chemistry , Nanoparticles/chemistry , Animals , Cattle , Drug Delivery Systems , Hydrogen-Ion Concentration , Microscopy, Electron, Transmission , Nanoparticles/ultrastructure , Particle Size , Serum Albumin, Bovine/chemistry
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