77 research outputs found
Mesenchymal stem cells alleviate bacteria‐induced liver injury in mice by inducing regulatory dendritic cells
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102718/1/hep26670.pd
Cannabinoid Receptor Subtype 2 (Cb2R) Agonist Gw405833 Reduces Agonist-Induced Ca2+ Oscillations In Mouse Pancreatic Acinar Cells
Emerging evidence demonstrates that the blockade of intracellular Ca 2+ signals may protect pancreatic acinar cells against Ca 2+ overload, intracellular protease activation, and necrosis. The activation of cannabinoid receptor subtype 2 (CB 2 R) prevents acinar cell pathogenesis in animal models of acute pancreatitis. However, whether CB 2 Rs modulate intracellular Ca 2+ signals in pancreatic acinar cells is largely unknown. We evaluated the roles of CB 2 R agonist, GW405833 (GW) in agonist-induced Ca 2+ oscillations in pancreatic acinar cells using multiple experimental approaches with acute dissociated pancreatic acinar cells prepared from wild type, CB 1 R-knockout (KO), and CB 2 R-KO mice. Immunohistochemical labeling revealed that CB 2 R protein was expressed in mouse pancreatic acinar cells. Electrophysiological experiments showed that activation of CB 2 Rs by GW reduced acetylcholine (ACh)-, but not cholecystokinin (CCK)-induced Ca 2+ oscillations in a concentration-dependent manner; this inhibition was prevented by a selective CB 2 R antagonist, AM630, or was absent in CB 2 R-KO but not CB 1 R-KO mice. In addition, GW eliminated L-arginine-induced enhancement of Ca 2+ oscillations, pancreatic amylase, and pulmonary myeloperoxidase. Collectively, we provide novel evidence that activation of CB 2 Rs eliminates ACh-induced Ca 2+ oscillations and L-arginine-induced enhancement of Ca 2+ signaling in mouse pancreatic acinar cells, which suggests a potential cellular mechanism of CB 2 R-mediated protection in acute pancreatitis
A Temperature/pH Double-Responsive and Physical Double-Crosslinked Hydrogel Based on PLA and Histidine
Hydrogel is a good drug carrier, widely used in the sustained-release aspect of tumor drugs, which can achieve the continuous release of drugs to the tumor sites. In this study, diethylene glycol monomethyl ether methacrylate (MEO2MA) and poly (ethylene glycol) methyl ether methacrylate (OEGMA) are temperature-sensitive monomers. N-Methacryloyl-L-Histidine (Mist) is pH sensitive monomer and ligand for metal coordination bond. The temperature-sensitive monomers and pH sensitive monomer with stereocomplex of modified polylactic acid (HEMA-PLLA30/PDLA30) were mixed, under 2,2’-azobis (2-methylpropionitrile) (AIBN) as radical initiator, polymer was formed by free-radical polymerization. The polymer was then immersed in ZnSO4 solution, the imidazole group of Mist monomer forms a tridentate metal coordination bond with Zn2+, temperature/pH double-responsive and physical double-crosslinked hydrogel was finally obtained. Comparing the hydrogen bond hydrogel, hydrogen bond and metal coordination bond double crosslinking hydrogel, metal coordination bond hydrogel, testing thermal stability, viscoelasticity, swelling, and morphology of three hydrogels. In addition, using UV-Visible spectroscopy (UV-Vis) to test the sustained release of the hydrophobic drug doxorubicin hydrochloride (DOX-HCl) in the human tumor environment (37 °C, pH = 5). We found that the temperature/pH double-responsive and physical double-crosslinked hydrogel had the most potential for the sustained drug release
Synthesis and Properties of Hydrogels on Medical Titanium Alloy Surface by Modified Dopamine Adhesion
Medical titanium alloy Ti-6Al-4V (TC4) is an ideal surgical implant material for human tissue repair and replacement. TC4 implantation will be in close contact with human soft tissue and has mechanical compatibility problems. In order to solve this problem, the hydrogel was formed on the surface of TC4 by utilizing the adhesion of dopamine, and the storage modulus of the formed hydrogel matched that of human soft tissue. In this paper, the surface of TC4 was first modified with dopamine (DA) and 2-bromoisobutyryl bromide (BIBB). 2-(2-methoxyethoxy) ethyl methacrylate (MEO2MA), oligo (ethylene oxide) methacrylate (OEGMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) are used as monomers, and methylenebisacrylamide (MBA) is used as cross-linking agent. Thermosensitive hydrogels were formed on the surface of modified TC4 by the ATRP technique. The successful synthesis of initiator and hydrogels on TC4 was demonstrated by Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS). The morphology of the hydrogel was observed by the scanning electron microscope (SEM), and the water absorption and temperature sensitivity were investigated by the swelling property. The thermal and mechanical properties of these gels were measured using thermal analysis system (TAS) and dynamic mechanical analyzer (DMA). The results show that the hydrogel on TC4 has good thermal stability and storage modulus that matches human soft tissue
Assessment of the Health Effects of Heavy Metals Pollution of Agricultural Soils in the Iron Ore Mining Area of the Northern Piedmont of Mount Wutai, Shanxi Province, China
We have measured the concentrations of toxic elements (Cd, Pb, As, and Hg) in 29 samples from agricultural soils in an iron ore mining area in the northern piedmont of Mount Wutai in Shanxi Province, China. The aim was to evaluate the potential health risks to local inhabitants based on the health risk assessment model derived from the United States Environmental Protection Agency (USEPA). The results show that the concentrations of the four heavy metals exceed their background values, especially in the case of Hg. The pollution level of the four heavy metals can be ordered as follows: Hg > Cd > Pb > As. The spatial distribution of the concentrations of the four heavy metals was uneven: pollution levels were lowest in the basin of the E River, and centered on the E River there was an increasing trend towards the Yukou River in the west and the Yangyan River in the east. In terms of the degree of pollution, this trend can be summarized as: Qingyang River > Yangyan River > Yukou River > E River. The main form of ingestion of the metals was via mouth and nose, and the risk to children is higher than for adults. Iron ore mining was the main cause of the increased concentrations of As and Cd, which represent a cancer risk for humans
Mesoscopic Characteristics on Cracks of Three-Point Bending RC Beam with Corroded Reinforcement
The RC beam usually works under the combined action of external loads and corrosion expansion pressures, and the RC beams without corrosion of reinforcements have good mechanical performance. In this study, the mesoscopic models of the three-point bending RC beams with different aggregates, different aggregate contents, and different corrosion expansion pressures were built. The plastic strain and the deflection are analyzed. The results show that the cracks of the RC beam with polygon aggregates are more dispersed than circle aggregates. As the aggregate content increases, the maximum plastic strain and maximum deflection of the RC beam decrease. The aggregate contents increased from 25% to 35%, the maximum plastic strain decreased from 3.4 × 10−3 to 2.1 × 10−3, and the maximum deflection of the lower boundary of the beam decreased from 0.005 m to 0.004 m. Furthermore, the corrosion expansion pressure makes the plastic strain increase in the concrete cover
An Interactive Learning Network That Maintains Sentiment Consistency in End-to-End Aspect-Based Sentiment Analysis
Most of the aspect-based sentiment analysis research completes the two subtasks (aspect terms extraction and aspect sentiment classification) separately, and it cannot see the full picture and actual effect of the complete aspect-based sentiment analysis. The purpose of end-to-end aspect-based sentiment analysis is to complete the two subtasks of aspect terms extraction and aspect sentiment classification at the same time, and the current research in this area focuses on the connection between the two subtasks and uses the connection between them to construct the model. However, they rarely pay attention to the connection between different aspects and ignore the sentiment inconsistency within the aspects caused by the end-to-end model. Therefore, we propose an interactive learning network to maintain sentiment consistency, first using the multi-head attention mechanism to achieve the interaction between aspects and subtasks and then using the gate mechanism to design an auxiliary module to maintain sentiment consistency within aspect items. The experimental results on the datasets Laptop14, Restaurant14, and Twitter showed that, compared with the optimal benchmark method, the F1 values of the proposed method increased by 0.4%, 1.21%, and 5.22%, respectively. This indicates that the proposed method can effectively consider the relationships between aspect items and maintain emotional consistency within the aspect items
Association between dietary folate intake and the risk of osteoporosis in adults: a cross-sectional study
Abstract Background Increased intake of specific vitamins has been linked to a decreased prevalence of osteoporosis. However, the association between dietary folate intake and the risk of osteoporosis in the general population remains incompletely understood. Therefore, we aimed to determine the association between dietary folate intake and the risk of osteoporosis in the general population of the USA. Methods In this cross-sectional study, data from the National Health and Nutrition Examination Survey (2017–2020) were collected. Osteoporosis was considered to be indicated by a bone mineral density greater than 2.5 standard deviations below the mean of the young adult reference group. Dietary folate intake was measured by a 24-hour dietary recall. Multivariate logistic regression models and restricted cubic spline models were used. Results The study included 2297 participants (mean age: 63.69 ± 0.35 years), 49.92% of whom were female. In the general population, increased dietary folate intake was directly associated with a decreased risk of osteoporosis (P for trend = 0.005). In the age > 60 years and female subgroups, folate intake was inversely associated with the risk of osteoporosis (P for trend < 0.001). The dose‒response curve suggested that this association was nonlinear (P for nonlinearity = 0.015). Conclusions Our cross-sectional study provides initial insights into the inverse association between dietary folate intake and the risk of osteoporosis in the general U.S. population. Further research is needed to confirm these associations
Detection of Hepatitis C virus RNA using a novel hybridization chain reaction method that competitively dampens cascade amplification.
The hybridization chain reaction (HCR) is widely used for biosensing. However, HCR does not provide the required sensitivity. In this study, we reported a method to improve the sensitivity of HCR by dampening the cascade amplification. First, we designed a biosensor based on HCR, and an initiator DNA was used to trigger the cascade amplification. Optimization of the reaction was then performed, and the results showed that the limit of detection (LOD) for the initiator DNA was about 2.5 nM. Second, we designed a series of inhibitory DNAs to dampen the HCR cascade amplification, and DNA dampeners (50 nM) were applied in the presence of the DNA initiator (50 nM). One of the DNA dampeners (D5) showed the best inhibitory efficiency of greater than 80%. This was further applied at concentrations ranging from 0 nM to 10 nM to prohibit the HCR amplification caused by a 2.5 nM initiator DNA (the limit of detection for this initiator DNA). The results showed that 0.156 nM of D5 could significantly inhibit the signal amplification (p<0.05). Additionally, the limit of detection for the dampener D5 was 16 times lower than that for the initiator DNA. Based on this detection method, we achieved a detection limit as low as 0.625 nM for HCV-RNAs. In summary, we developed a novel method with improved sensitivity to detect the target designed to prohibit the HCR cascade. Overall, this method could be used to qualitatively detect the presence of single-stranded DNA/RNA
Recycled Poly(Ethylene Terephthalate) from Waste Textiles with Improved Thermal and Rheological Properties by Chain Extension
Annual production of textile fibers is continuing to rise and the substantial discharge of undegradable waste polyester fibers can cause serious environmental and even health problems. Thus, the recycling and reuse of recycled poly(ethylene terephthalate) from waste textiles (rPET-F) is highly desirable but still challenging. Here, five chain extenders with a different number of epoxy groups per molecules were used to blend with discarded PET fibers and improve its viscosity and quality loss in the recycling process. The molecule weight, thermal properties, rheological properties and macromolecular architecture of modified r-PET were investigated. It was found that all modified rPET-F samples show higher viscosities and better thermal properties. rPET-F modified by difunctional EXOP molecules show linear structure and improved rheological properties. rPET-F modified by polyfunctional commercial ADR and synthesized copolymers exhibit a long chain branched structure and better crystallization. This study reveals a deeper understanding of the chain extension and opens an avenue for the recycling of PET textiles
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