RESUMEN
Exploring the physical fractions of organic carbon and influencing mechanisms in grassland, forest, and farmland soils in wind erosion area can provide scientific basis for carbon sequestration, land utilization, wind prevention measure making, and fertility restoration of sloping farmland in the region. We examined the differentiation of aggregate organic carbon and density fractionation organic carbon in 0-15 cm soil layer across grassland, forest, and sloping farmland with 350 m long and 5° slope gradient in the wind erosion area of Meilisi District, Qiqihar, Heilongjiang, as well as the sloping farmland in the downhill section, middle section, and uphill section with every 100 m apart from the bottom to the top. The results showed that soil aggregates >2 mm were all destroyed across grassland, forest, and farmland soils, while the percentage of aggregates <0.053 mm was significantly higher than that of other sizes. The percentage of various soil aggregates, organic carbon content from density fractionations, and the proportion of organic carbon in the heavy fraction aggregates in farmland were significantly lower than that in grassland and forest soils. Soil aggregates in the uphill section of farmland were completely destroyed, and organic carbon content in various size aggregates and density fractionations gradually decreased with increasing slope. The proportion of organic carbon in the heavy fraction aggregates decreased, but that in light fraction aggregates increased gradually. Soil organic carbon and available potassium were key factors affecting aggregate stability, aggregate organic carbon content, and organic carbon content in density fractionations, while the loss of organic carbon in aggregate led to a decrease in aggregate stability. In summary, compared with grassland and forest soils, the stability of soil aggregates, the aggregate organic carbon content, the organic carbon content in density fractionations, and the proportion of organic carbon in heavy fraction aggregates in farmland all decreased in the wind erosion area of Northeast China. With the increases of slope, the aggregate organic carbon content, the organic carbon content in density fractionations, and the proportion of organic carbon in the heavy fraction aggregates in sloping farmland all decreased. Planting trees, conserving and expanding grassland area, and increasing the application of organic materials in sloping farmland in wind erosion area are effective approaches to stabilize and increase carbon storage, improve soil structure, and enhance soil quality.
Asunto(s)
Carbono , Compuestos Orgánicos , Suelo , Viento , China , Carbono/análisis , Carbono/química , Suelo/química , Compuestos Orgánicos/análisis , Productos Agrícolas/crecimiento & desarrollo , Pradera , Erosión del Suelo , Bosques , Árboles/crecimiento & desarrollo , Poaceae/crecimiento & desarrollo , Conservación de los Recursos Naturales , EcosistemaRESUMEN
Noninvasive wound closure remains a challenge in the field of wound healing. In this study, we report the development of a cross-linked P-GL hydrogel constructed from polyvinyl alcohol (PVA) and GL (a hydrogel consisting of gallic acid and lysozyme) that effectively promotes wound closure and healing. The P-GL hydrogel exhibited a unique lamellar and tendon-like fibrous network structure, providing good thermo-sensitivity and tissue adhesiveness up to 60 MPa, as well as retaining autonomous self-healing and acid resistance capacities. In addition, the P-GL hydrogel exhibited sustained release characteristics lasting >100 h, excellent biocompatibility both in vitro and in vivo, as well as good antibacterial activity and mechanical properties. The in vivo full-thickness skin wounds model revealed the positive wound closure and healing therapeutic effects of the P-GL hydrogels were confirmed, showing a promising potential as a noninvasive wound closure and healing bio-adhesive hydrogel.
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Hidrogeles , Alcohol Polivinílico , Hidrogeles/farmacología , Hidrogeles/química , Alcohol Polivinílico/química , Ácido Gálico/farmacología , Muramidasa/farmacología , Cicatrización de Heridas , Antibacterianos/farmacología , Antibacterianos/químicaRESUMEN
Subarachnoid hemorrhage (SAH) is a severe acute cerebrovascular event that not only impairs the central nervous system but also negatively affects various other organs, including the heart. The underlying mechanisms, however, remain unclear. In this study, we discovered that mice with SAH exhibited significant cardiac injuries, such as extended QT and QTc intervals, cardiac fibrosis, and reduced cardiac ejection fractions. This phenomenon was accompanied by increased galectin-3 expression in the cardiac ventricle and can be reversed by galectin-3 inhibitor TD139. Interestingly, we also observed increased co-expression of galectin-3 in macrophage within the heart tissue of SAH mice. Additionally, when macrophage activation was suppressed using the beta-blocker propranolol, cardiac function improved, and galectin-3 expression in the cardiac tissue decreased. Collectively, our findings offer new insights into the role of galectin-3 in SAH-related cardiac dysfunction and suggest a macrophage-galectin-3 axis as a potential therapeutic strategy.
Asunto(s)
Cardiopatías , Hemorragia Subaracnoidea , Animales , Ratones , Galectina 3/genética , Galectina 3/metabolismo , Hemorragia Subaracnoidea/metabolismo , Corazón , Macrófagos/metabolismo , Cardiopatías/complicacionesRESUMEN
Mucoadhesive hydrogels with multifunctional properties such as gastric acid resistance and sustained drug release in the intestinal tract are highly desirable for the oral treatment of inflammatory bowel diseases (IBDs). Polyphenols are proven to have great efficacies compared with the first-line drugs for IBD treatments. We recently reported that gallic acid (GA) was capable of forming a hydrogel. However, this hydrogel is prone to easy degradation and poor adhesion in vivo. To tackle this problem, the current study introduced sodium alginate (SA) to form a gallic acid/sodium alginate hybrid hydrogel (GAS). As expected, the GAS hydrogel showed excellent antiacid, mucoadhesive, and sustained degradation properties in the intestinal tract. In vitro studies demonstrated that the GAS hydrogel significantly alleviated ulcerative colitis (UC) in mice. The colonic length of the GAS group (7.75 ± 0.38 cm) was significantly longer than that of the UC group (6.12 ± 0.25 cm). The disease activity index (DAI) value of the UC group was (5.5 ± 0.57), which was markedly higher than that of the GAS group (2.5 ± 0.65). The GAS hydrogel also could inhibit the expression of inflammatory cytokines, regulating macrophage polarization and improving the intestinal mucosal barrier functions. All these results indicated that the GAS hydrogel was an ideal candidate for oral treatment of UC.
Asunto(s)
Colitis Ulcerosa , Colitis , Ratones , Animales , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/tratamiento farmacológico , Colitis Ulcerosa/metabolismo , Hidrogeles/metabolismo , Preparaciones de Acción Retardada/metabolismo , Colon/metabolismo , Alginatos , Ácido Gálico/metabolismo , Sulfato de Dextran/efectos adversos , Modelos Animales de Enfermedad , Colitis/tratamiento farmacológico , Ratones Endogámicos C57BLRESUMEN
The current antibacterial wound dressings with antibiotic substances or metal bactericidal agents may lead to severe multidrug resistance and poor biocompatibilities. Herein, we report an inherent antibacterial hydrogel constructed by only two naturally small molecules gallic acid (GA) and diammonium glycyrrhizinate (DG) for promoting Staphylococcus aureus (S. aureus)-infected wound healing. The resultant GAD hydrogel can be fabricated by co-assembly of these two materials through simple steps. Thanks to the incorporation of GA and DG, GAD hydrogel enabled a strong mechanical performance and great self-healing property with a sustained-release of drugs into skin wounds. Moreover, the cell viability assays showed that GAD hydrogel had good cytocompatibility by promoting cell proliferation and migration. In addition, GAD hydrogel had broad antibacterial efficiency against both Gram-positive and Gram-negative bacteria. Taken together, GAD hydrogel is a promising dressing to accelerate bacterial-infected wound healing through reconstructing an intact and thick epidermis without antibiotics or cytokines.
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Ácido Glicirrínico , Hidrogeles , Ácido Glicirrínico/farmacología , Hidrogeles/farmacología , Bacterias Gramnegativas , Antibacterianos/farmacología , Bacterias Grampositivas , Staphylococcus aureus , Ácido Gálico/farmacologíaRESUMEN
Wound healing remains a critical challenge due to its vulnerability to bacterial infection and the complicated inflammatory microenvironment. Herein, we report a novel antibacterial hydrogel constructed only by gallic acid (GA) and phycocyanin (PC), which is expected for the treatment of bacteria-infected wounds. These GA/PC hydrogels (GP) was found to coassemble into fibrous networks with a diameter of around 2 µm mainly through noncovalent interactions of hydrogen bonds, van der Waals force, and π interaction. Notably, these GP hydrogels showed excellent rheological properties (i.e., storage modulus of more than 9.0 × 104 Pa) and outstanding biocompatibility and antibacterial activities. Thanks to the incorporation of GA and PC, the GP hydrogels enabled adherence to the moist wound tissue and achieved a sustained release of GA and PC into the wound skin, therefore effectively attenuating inflammation and accelerating wound healing both in normal mice and bacteria-infected mice through regulating the expression of the tight junction protein and the alleviation of oxidative stress. Considering these results, these GP hydrogels are demonstrated to be a promising candidate for bacteria-infected wound healing.
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Antibacterianos , Hidrogeles , Animales , Ratones , Hidrogeles/farmacología , Antibacterianos/farmacología , Ácido Gálico/farmacología , Estrés Oxidativo , Cicatrización de HeridasRESUMEN
The purpose of this study is to provide a new strategy for constructing a temperature-controlled hydrogel as a promising agent for wound healing using natural products through physical co-assembly. Herein, the temperature-controlled physically assembled hydrogel consisting of gallic acid and lysozyme (GL) could be co-assembled into a regular fibrous structure accompanied by strong blue fluorescence with three-dimensional networks at micron levels through hydrophobic interactions, π-π interactions and hydrogen bonding. This GL hydrogel has excellent temperature sensitivity and self-healing properties, as proved by cycle high-low temperature tests. In addition, it possesses stable rheological properties, great sustained release ability, and could realize the spatiotemporal delivery of gallic acid and lysozyme. Biocompatibility and antibacterial tests proved that this well-assembled GL hydrogel has no cytotoxicity but excellent antibacterial activity. Both in vitro and in vivo experiments demonstrated that the GL hydrogel has excellent anti-inflammation efficiency and promotes the healing of chronic wounds by suppressing the expression of pro-inflammatory related genes. Tests using an E. coli-infected wound model confirmed that the GL hydrogel could terminate the inflammatory phase early and ultimately promote the healing of wounds infected by E. coli. This study provides a promising strategy for the effective treatment of wounds through a physical self-assembled hydrogel.
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Antiinfecciosos , Hidrogeles , Hidrogeles/química , Muramidasa , Escherichia coli , Ácido Gálico , Preparaciones de Acción Retardada , Antibacterianos/farmacología , Antibacterianos/químicaRESUMEN
Dexmedetomidine is an α2 adrenoceptor agonist and has cardioprotective effect,the mechanism of which is being studied.Increasing studies have proved the clinical value of dexmedetomidine in reducing postoperative complications and improving the prognosis of patients.Therefore,this review summarizes the cardiac protection mechanism of dexmedetomidine based on the existing studies and expounds the application of dexmedetomidine in the perioperative period of cardiovascular surgery.
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Dexmedetomidina , Dexmedetomidina/farmacología , Dexmedetomidina/uso terapéutico , Corazón , HumanosRESUMEN
Programing self-assembly of naturally bioactive molecules has been a wide topic of great significance for biomedical uses. Despite the fact that plant-derived polyphenols with catechol or pyrogallol moieties have been widely studied to construct nanocomplexes or nanocoatings via self-polymerization, there is no report on the self-assembly of these polyphenols into therapeutic hydrogels for potential applications. Here, we reported that adding a very small amount of resveratrol (Res) into the gallic acid (GA) aqueous solution could trigger the quick self-assembly of GA to form a fibrous hydrogel within 5 min through hydrogen bonds and π-π interactions. The length of GA/Res (GR) fibrils in gels varied from 100 to 1000 microns, with a diameter of around 1 µm. Notably, these GR hydrogels showed excellent colloid stability, providing better slow release and outstanding biocompatibility. Also, in vivo experiments indicated the hydrogels had high antibacterial effects and excellent wound healing capabilities in a total skin defect model via regulating the expression of inflammatory factors (IL-6, IL-1ß, and TNF-α) due to the release of therapeutic agents (GA and Res) into the matrix. Overall, our results provide a new strategy to accelerate self-assembly of GA by adding Res to form hydrogels, which is further proved as a promising therapeutic carrier for wound healing.
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Ácido Gálico , Hidrogeles , Antibacterianos/farmacología , Ácido Gálico/química , Ácido Gálico/farmacología , Hidrogeles/química , Hidrogeles/farmacología , Polifenoles , Resveratrol/farmacología , Cicatrización de HeridasRESUMEN
Melodicochinines A - D (1-4), four new monoterpene indole alkaloids (MIAs), along with 21 known ones, were isolated from the stems and twigs of Melodinus cochinchinensis. Their structures were elucidated on the basis of extensive spectroscopic analysis. A ubiquitin-rhodamine 110 assay showed that 11-methyloxytabersonine had potential inhibitory effect against ubiquitin-specific protease 7 (USP7).
Asunto(s)
Apocynaceae/química , Extractos Vegetales/química , Alcaloides de Triptamina Secologanina/aislamiento & purificación , China , Cromatografía Líquida de Alta Presión , Espectroscopía de Resonancia Magnética , Rotación Óptica , Extractos Vegetales/aislamiento & purificación , Tallos de la Planta/química , Alcaloides de Triptamina Secologanina/química , Espectrofotometría InfrarrojaRESUMEN
Uralins A - D, four undescribed polycyclic polyprenylated acylphloroglucinols (PPAPs) featuring an unprecedented fused hexacyclic architecture, a unique monocyclic tetra-seco-tetranor-b-PPAP, an oxidative b-PPAP and a rare norspiroindane-type m-PPAP, respectively, were isolated from the aerial parts of Hypericum uralum, along with ten known PPAPs. Their structures and absolute configurations were elucidated by extensive spectroscopic techniques (MS, NMR, [α]D, CD), conceivable biogenetic pathways and time-dependent density functional theory-based electronic circular dichroism (TDDFT-ECD) calculations. Biological assays showed three b-PPAPs had moderate antioxidative damage activities, while spiroindanes exhibited moderate cytotoxic effects.