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1.
J Environ Sci (China) ; 113: 356-364, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34963543

RESUMEN

Considerable research efforts have been devoted to increase phosphorus (P) availability during aerobic composting. However, there is little discussion weather the dissolved organic carbon (DOC) controls the transformation among P-fractions. Thus, we investigated the changes in DOC compositions and P-fractions during biochar-amended composting (wet weight basis, 5% and 10%). TP content continuously increased since the 'concentration effect' during aerobic composting. NaHCO3-Pi, NaOH-Pi and HCl-Pi were main P-fractions, and biochar can improve P-bioavailability by transforming NaOH-Pi and HCl-Pi into NaHCO3-Pi. Structure equation models (SEMs) indicated that biochar enhanced the P-bioavailability through regulating the decomposition of DOC. Our results at least hint that the activation mechanism on P under the influence of DOC during biochar-amended composting.


Asunto(s)
Compostaje , Disponibilidad Biológica , Carbón Orgánico , Fósforo , Suelo
2.
Chemosphere ; 287(Pt 3): 132346, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34826956

RESUMEN

A novel control strategy is developed for a municipal wastewater treatment plant (WWTP) consisting of anaerobic-anoxic-aerobic reactors. The idea is to generate more organic matter with a reduction of nitrate concentration in the anoxic section so that more biological phosphorus (P) removal happens. For this, the Supervisory and Override Control Approach (SOPCA) is designed based on the benchmark simulation model (BSM1-P) and is evaluated by considering dynamic influent. In the supervisory layer, proportional integral (PI) and fuzzy controllers are designed. Additionally, dissolved oxygen (So) control loops in the aerobic reactors are designed. PI controller is designed for control of nitrate levels in the anoxic reactors and is integrated with override control and supervisory layer. It is found that the novel SOPCA approach gave better nutrient removal with slightly higher operating costs when So control is not put in place. With three So control loops in place, the WWTP showed better effluent quality and lower cost. Here, the improved removal efficiency of 28.5% and 20.5% are obtained when Fuzzy and PI control schemes respectively are used in the supervisory layer. Therefore, the application of SOPCA is recommended for a better P removal rate.


Asunto(s)
Fósforo , Purificación del Agua , Reactores Biológicos , Nitrógeno , Oxígeno , Eliminación de Residuos Líquidos
3.
Glob Chang Biol ; 27(24): 6578-6591, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34606141

RESUMEN

Phosphorus (P) is essential for productivity of alpine grassland ecosystems, which are sensitive to global warming. We tested the hypotheses that (1) mobilized 'calcium-bound inorganic P' (Ca-Pi ) is a major source of plant-available P in alpine meadows with alkaline soils after long-term warming, (2) mobilization of Ca-Pi is linked to effective plant carboxylate-releasing P-acquisition strategies under warming, and (3) the mobilization is also related to plant nitrogen (N)-acquisition. We conducted an 8-year warming experiment in an alpine meadow (4635 m above sea level) on the Qinghai-Tibetan Plateau. A significant increase in P concentration in both aboveground and belowground biomass indicates an increased mobilization and assimilation of P by plants under warming. We observed a significant decrease in Ca-Pi , no change in moderately-labile organic P, and an increase in highly resistant organic P after warming. There was no increase in phosphatase activities. Our results indicate that Ca-Pi , rather than organic P was the major source of plant-available P for alpine meadows under warming. Higher leaf manganese concentrations of sedges and forbs after warming indicate that carboxylates released by these plants are a key mechanism of Ca-Pi mobilization. The insignificant increase in Rhizobiales after warming and the very small cover of legumes show a minor role of N-acquisition strategies in solubilizing phosphate. The insignificant change in relative abundance of mycorrhizal fungi and bacteria related to P cycling after warming shows a small contribution of microorganisms to Ca-Pi mobilization. The significant increase in leaf N and P concentrations and N:P ratio of grasses and no change in sedge leaf N:P ratio reflect distinct responses of plant nutrient status to warming due to differences in P-acquisition strategies. We highlight the important effects of belowground P-acquisition strategies, especially plant carboxylate-releasing P-acquisition strategies on responses of plants to global changes in alpine meadows.


Asunto(s)
Fósforo , Suelo , Ecosistema , Pradera , Fosfatos , Tibet
4.
Environ Sci Technol ; 55(20): 14185-14193, 2021 10 19.
Artículo en Inglés | MEDLINE | ID: mdl-34623819

RESUMEN

Polyphosphate-accumulating organisms (PAOs), which can store high levels of phosphate (Pi) in the form of polyphosphate (polyP), are employed to engineer enhanced biological P removal (EBPR) from wastewaters. Co-localization of Mg and K in polyP granules of PAOs has been reported, and higher abundance of Mg-polyP granules relative to other metal complexes was correlated positively with EBPR performance stability. However, the underlying mechanism remains unknown. Here, we obtained molecular structural information of hydrated polyP complexes with four physiologically relevant metal cations (Na+, K+, Ca2+, and Mg2+) using computational and experimental techniques. Molecular dynamics simulations revealed that Mg-polyP and K-polyP complexes were the most and least stable of the complexes, respectively, suggesting that the co-occurrence of these complexes facilitates variable polyP bioavailability. The relative thermodynamic stability reflected the strength of metal chelation whereby the coordination distance between the polyP ligand O and the metal was 1.71-2.01 Å for Mg2+ but this distance was 2.64-2.70 Å for K+. Pair distribution function analysis of X-ray scattering data obtained with a Mg-polyP solution corroborated the theoretical Mg-polyP coordination geometry. These findings implied a possible mechanistic role of metal complexation in the P cycling traits of PAOs in engineered and natural systems.


Asunto(s)
Complejos de Coordinación , Polifosfatos , Reactores Biológicos , Fósforo , Aguas Residuales , Rayos X
5.
Physiol Plant ; 173(4): 2068-2080, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34516676

RESUMEN

Invasive plants rapidly spread in habitats with low soil phosphorus (P) availability and have triggered a sharp decline in the diversity of native species. However, no studies have explored how widespread invasive species acclimate to low soil P availability via changing foliar P fractions, especially under elevated atmospheric CO2 concentrations ([CO2 ]) and nitrogen (N) deposition. Here, an open-top chamber experiment was conducted to explore the effect of nutrient addition and elevated [CO2 ] on leaf traits and foliar functional P fractions (i.e., Pi, metabolite P, lipid P, nucleic acid P, and residual P) of two aggressive invasive species (Mikania micranatha and Chromolaena odorata). We found that foliar N/P ratios were more than 20, and P addition significantly increased plant biomass. Both results indicated P-limited plant growth at our studied site. Elevated [CO2 ], N and N + P addition greatly increased plant biomass, photosynthetic rates, and photosynthetic P-use efficiency (PPUE) in invasive species, but PPUE decreased with increasing P addition. Nitrogen addition slightly decreased the concentration of leaf total P, decreased foliar residual P, but increased metabolite P concentrations in invasive species. Similar changes in foliar P fractions were found under N + P addition. Phosphorus addition increased foliar P concentrations, which was strongly correlated with an increase in metabolite P concentrations in invasive species. Elevated [CO2 ] alleviated these effects and increased PPUE. The present results suggest that future elevated [CO2 ] and N deposition allow the invasive species to acclimate to low soil P availability and support their successful invasion by greatly reducing P allocation to non-metabolite foliar P fractions (i.e., nucleic acid P and residual P) to meet their demand of metabolite P for photosynthesis and exhibit a high PPUE.


Asunto(s)
Chromolaena , Mikania , Dióxido de Carbono , Nitrógeno , Fósforo
6.
Int J Mol Sci ; 22(17)2021 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-34502220

RESUMEN

Phosphorus (P) is an essential macronutrient, playing a role in developmental and metabolic processes in plants. To understand the local and systemic responses of sorghum to inorganic phosphorus (Pi) starvation and the potential of straw and ash for reutilisation in agriculture, we compared two grain (Razinieh) and sweet (Della) sorghum varieties with respect to their morpho-physiological and molecular responses. We found that Pi starvation increased the elongation of primary roots, the formation of lateral roots, and the accumulation of anthocyanin. In Razinieh, lateral roots were promoted to a higher extent, correlated with a higher expression of SbPht1 phosphate transporters. Infrared spectra of straw from mature plants raised to maturity showed two prominent bands at 1371 and 2337 cm-1, which could be assigned to P-H(H2) stretching vibration in phosphine acid and phosphinothious acid, and their derivates, whose abundance correlated with phosphate uptake of the source plant and genotype (with a higher intensity in Razinieh). The ash generated from these straws stimulated the shoot elongation and root development of the rice seedlings, especially for the material derived from Razinieh raised under Pi starvation. In conclusion, sorghum growing on marginal lands has potential as a bio-economy alternative for mineral phosphorus recycling.


Asunto(s)
Oryza/crecimiento & desarrollo , Fósforo/metabolismo , Desarrollo de la Planta , Proteínas de Plantas/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Brotes de la Planta/crecimiento & desarrollo , Sorghum/metabolismo , Regulación de la Expresión Génica de las Plantas , Oryza/metabolismo , Proteínas de Transporte de Fosfato/metabolismo , Raíces de Plantas/metabolismo , Brotes de la Planta/metabolismo , Sorghum/química , Estrés Fisiológico
7.
Toxicol Appl Pharmacol ; 428: 115671, 2021 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-34391753

RESUMEN

Breast cancer, a heterogeneous disease, has the highest incidence rate and is a major cause of death in females worldwide. Drug delivery by using nanotechnology has shown great promise for improving cancer treatment. Nanoliposomes are known to have enhanced accumulation ability in tumors due to prolonged systemic circulation. Peptide 18 (P18), a tumor homing peptide targeting keratin-1 (KRT-1), was previously shown to have high binding affinity towards breast cancer cells. In this study, we investigate the ability of P18 conjugated PEtOx-DOPE nanoliposomes (P18-PEtOx-DOPE) for the targeted delivery of doxorubicin to AU565 breast cancer model. Toxicology studies of PEtOx-DOPE nanoliposomes performed on normal breast epithelial cells (MCF10A), showed minimal toxicity. Doxorubicin delivery by P18-PEtOx-DOPE to AU565 cells induces cytotoxicity in a dose and time dependent manner causing mitotic arrest in G2/M phase at 24 h. Anti-cancer activity of P18-PEtOx-DOPE-DOX nanoliposomes on AU565 cells was detected by Annexin V/PI apoptosis assay. In terms of in vivo antitumor efficacy, P18-PEtOx-DOPE-DOX nanoliposomes administration to AU565 CD-1 nu/nu mice model showed significant decrease in tumor volume suggesting that DOX delivered by these nanoliposomes elicited a strong antitumor response comparable to the free delivery of doxorubicin. Overall, our results offered preclinical proof for the use of P18-PEtOx-DOPE-DOX nanoliposomes in KRT-1+ breast cancer therapy.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Doxorrubicina/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Nanopartículas/administración & dosificación , Fosfatidiletanolaminas/administración & dosificación , Poliaminas/administración & dosificación , Animales , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Doxorrubicina/farmacocinética , Femenino , Liposomas , Ratones , Ratones Desnudos , Nanopartículas/metabolismo , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/farmacocinética , Fosfatidiletanolaminas/farmacocinética , Poliaminas/farmacocinética , Carga Tumoral/efectos de los fármacos , Carga Tumoral/fisiología
8.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 37(3): 332-336, 2021 May.
Artículo en Chino | MEDLINE | ID: mdl-34374249

RESUMEN

Objective: To investigate the effects of estrogen receptor α (ERα) gene overexpression on bone metabolism and calcium and phosphorus metabolism in ovariectomized osteoporosis mice, and to provide experimental basis for targeted gene therapy of osteoporosis. Methods: Thirty SPF female mice were randomly divided into sham operation group, model group and ERα overexpression group with 10 mice in each group. After the model was established, the ERα overexpression group was transfected with recombinant adenovirus vector carrying mouse ERα gene by intraspinal injection. The model group was transfected with empty virus, and the sham operation group was not treated. The expression of ERα gene in bone tissue of mice was detected by quantitative Real-time PCR (qRT-PCR). Bone mineral density (BMD) of mouse femur was measured after modeling. Trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular segregation (Tb.Sp), bone volume fraction (BV/TV) and biomechanical strength of femur were measured by micro-CT scanning. Serum levels of calcium (Ca), phosphorus (P), osteocalcin (BGP) and alkaline phosphatase (ALP) were measured by automatic biochemical analyzer. The expressions of tissue inhibitor of metalloproteinases 1 (TIMP-1) and monocyte chemotactic protein 1 (MCP-1) in bone homogenate were detected by Immunohistochemistry. Results: Compared with sham operation group, the expression level of ERα gene in bone tissue of model group was decreased significantly, the levels of BMD, BV/TV, Tb. Th, maximum load, rigidity coefficient, Ca and P were decreased, while the levels of Tb. Sp, BGP and ALP were increased significantly (P<0.05). Compared with the sham operation group, the expression level of TIMP-1 protein in the bone tissue of the model group was significantly decreased, while that of MCP-1 protein was increased, while that of the ERα overexpression group was increased while that of MCP-1 was decreased (P<0.05).The levels of ERα gene expression, BMD, BV/TV, TB. Th, maximum load, rigidity coefficient, Ca and P in the ERα overexpression group were significantly higher than those in the model group, while Tb. Sp, BGP and ALP were significantly lower (P<0.05). Compared with the sham operation group, mean optical density of TIMP-1 in the bone tissue of the model group was significantly decreased, while that of MCP-1 was significantly increased, and that of the ERα overexpression group was significantly increased while that of MCP-1 was significantly decreased (P<0.05). Conclusion: ERα gene overexpression can improve osteoporosis by regulating bone mineral density, bone parameters, bone metabolism, calcium and phosphorus metabolic indicators and the expression levels of TIMP-1 and MCP-1 in tissues.


Asunto(s)
Densidad Ósea , Osteoporosis , Animales , Calcio , Receptor alfa de Estrógeno/genética , Femenino , Humanos , Ratones , Ovariectomía , Fósforo , Ratas , Ratas Sprague-Dawley
9.
Chemosphere ; 284: 131391, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34328082

RESUMEN

Effective removal and recovery of phosphorus (P) from the aquatic environment was of great significance for eutrophication control and P recovery. This study investigated the effects of different environmental conditions on P adsorption by biochar (BC) and the feasibility of applying the P-laden BC as a fertilizer for plant growth. The nano zero-valent iron (nZVI) modified reeds BC prepared at 700 °C (Fe-700-BC) had the maximum P adsorption capacity of 95.2 mg g-1, which was higher than those prepared at 300, 500, and 900 °C. The addition of Fe-700-BC reduced the concentration of total phosphorus (TP) in the overlying water, in which the soluble reactive phosphorus (SRP) almost completely removed, as well as had a certain inhibitory effect on the growth of algae. Simultaneously, Fe-700-BC reduced the contents of different fractions of P (weakly adsorbed inorganic phosphorus (WA-Pi), potential active inorganic phosphorus (PA-Pi), and Fe/Al-bound inorganic phosphorus (Fe/Al-Pi)) by adsorbing the soluble P released from the sediments, especially in the case of disturbance. Fe-700-BC had no significant effect on the diversity and richness of the microbial community in the sediment. Moreover, P-laden BC was safe and environmentally friendly for application in the soil and tended to increase stem and root length, fresh and dry weight at low doses (0.5 wt%) in wheat planting experiments. The present work could provide a reference for solving the problems related to eutrophication and P deficiency.


Asunto(s)
Fósforo , Contaminantes Químicos del Agua , Carbón Orgánico , Hierro/análisis , Agua , Contaminantes Químicos del Agua/análisis
10.
Fish Shellfish Immunol ; 116: 12-18, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33965526

RESUMEN

Triploid induction is a promising biotechnique that could be used to enhance aquaculture yields in the near future. However, studies conducted with several fish species have demonstrated that the presence of an extra set of chromosomes may result in deleterious health effects. Furthermore, studies of fish immune responses still need to be conducted before these specimens can be readily commercialized. In the study presented herein, we evaluated the effects of triploid induction on hematology, erythrocyte morphometry and morphology, phagocytosis, and the expression levels of IL-1ß and TGF-ß using specimens of the Neotropical species, Astyanax altiparanae. In general, the cell counts of erythrocytes, leukocytes, and neutrophils in triploid fish were lower than those in diploid fish. The erythrocytes of triploid fish were larger than those found in diploid fish, but also demonstrated considerably higher frequencies of cellular and nuclear abnormalities. Although not statistically significant, triploid induction resulted in a phagocytic capacity (PC) 20% lower than that found with diploid fish. No notable differences were observed in phagocytic index (PI). Gene expression levels for the cytokine IL-1 were lower in tissues from the head kidney, liver, and spleen of triploid fish with respect to diploid fish. Gene expression levels of TGF-ß were lower only in the spleen of triploids compared to diploids. In conclusion, triploid induction resulted in A. altiparanae specimens with immune impairments and potentially lower resistances to disease and low-quality environments.


Asunto(s)
Characidae , Inmunidad Innata , Triploidía , Animales , Characidae/sangre , Characidae/genética , Characidae/inmunología , Eritrocitos , Femenino , Proteínas de Peces/genética , Pruebas Hematológicas , Interleucina-1beta/genética , Leucocitos/inmunología , Masculino , Fagocitosis , Saccharomyces cerevisiae , Factor de Crecimiento Transformador beta/genética
11.
Chemosphere ; 280: 130599, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33940448

RESUMEN

A novel method of predicting heavy metal concentration in lake water by support vector machine (SVM) model was developed, combined with low-cost, easy to obtain nutrients and physicochemical indicators as input variables. 115 surface water samples were collected from 23 sites in Chaohu Lake, China, during different hydrological periods. The particulate concentrations of heavy metals in water were much higher than the dissolved concentrations. According to Nemerow pollution index (Pi), pollution degrees by Fe, V, Mn and As ranged from heavy (2 ≤ Pi < 4) to serious (Pi ≥ 4). The concentrations of most heavy metals were the highest during the medium-water period and the lowest during the dry season. Non-metric Multidimensional Scaling Analysis confirmed heavy metal concentrations had slight spatial difference but relatively large seasonal variation. Redundancy Analysis indicated the close associations of heavy metals with nutrient and physicochemical indicators. When both nutrient and physicochemical indicators were used as input variables, the simulation effects for most elements in total and particulate were relatively better than those obtained using only nutrient or only physicochemical indicators. The simulation effects for As, Ba, Fe, Ti, V and Zn were generally good, based on their training R values of 0.847, 0.828, 0.856, 0.867, 0.817 and 0.893, respectively, as well as their test R values of 0.811, 0.836, 0.843, 0.873, 0.829 and 0.826, respectively; and meanwhile, in both the training and test stages, these metals also had relatively lower errors. The spatial distribution of heavy metals in Chaohu Lake was then predicted using the fully trained SVM models.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Sedimentos Geológicos , Lagos , Metales Pesados/análisis , Nitrógeno/análisis , Nutrientes , Fósforo/análisis , Máquina de Vectores de Soporte , Agua , Contaminantes Químicos del Agua/análisis
12.
Exp Eye Res ; 208: 108614, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33971221

RESUMEN

The aim of this study was to investigate the efficacy of intravitreal povidone-iodine (PI) in the treatment of vancomycin-resistant Enterococcus faecalis (VRE) endophthalmitis. Fifty New Zealand white rabbits were divided into 5 groups (n = 10 in each group). After the induction of endophthalmitis using VRE (minimum inhibitory concentration [MIC] ≥ 40 µg/mL) in the right eye, Group A, B, C, and D received intravitreal injections of 0.1% PI, 0.3% PI, 0.05% vancomycin, and 0.5% vancomycin, respectively. Eyes in Group E were used as controls. Fundus photography, vitreous culture, electroretinography (ERG), and histologic examinations of the retina were conducted on day 14. A marked improvement in endophthalmitis was observed in Group A, B, C and D, compared to Group E. Fundus photographs showed mild vitreous opacities in Group A and B, and moderate vitreous opacity in Group C. All eyes in Group D had a clear vitreous. In vitreous culture, bacterial growth was found in 6 eyes (100, 200, 200, 400, 500, and 500 colony-forming units) in Group C, but not in Groups A, B, or D. ERG and histological examination also indicated intraocular damage in Group C. Our results show that intravitreal injection of PI, even at low concentrations, was effective for treatment of VRE endophthalmitis, although some vitreous opacity remained. Intravitreal vancomycin injection was also useful to treat resistant strains, if used at a higher concentration within the safety threshold.


Asunto(s)
Endoftalmitis/tratamiento farmacológico , Enterococcus faecalis/aislamiento & purificación , Infecciones Bacterianas del Ojo/tratamiento farmacológico , Infecciones por Bacterias Grampositivas/tratamiento farmacológico , Povidona Yodada/administración & dosificación , Resistencia a la Vancomicina , Animales , Antiinfecciosos Locales/administración & dosificación , Recuento de Colonia Microbiana , Modelos Animales de Enfermedad , Electrorretinografía , Endoftalmitis/microbiología , Endoftalmitis/patología , Infecciones Bacterianas del Ojo/microbiología , Infecciones Bacterianas del Ojo/patología , Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/patología , Inyecciones Intravítreas , Conejos , Retina/patología , Cuerpo Vítreo/microbiología , Cuerpo Vítreo/patología
13.
Environ Pollut ; 285: 117382, 2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-34049130

RESUMEN

Clarifying the properties/features of nutrient loss from farmland surface runoff is essential for the mitigation of nutrient losses. Plough pan formation underneath topsoil is a common feature of long-term paddy soils that significantly affects water movement and nutrient runoff loss, especially during the upland season of paddy-upland rotation. To characterize the nutrients that are lost from wheat fields of paddy-wheat rotation with runoff, a field experiment was conducted in a wheat field using a simulated rainfall system from November 2019 to May 2020 in Nanjing, China. The aim of this study was to investigate the temporal characteristics of nitrogen (N) and phosphorus (P) loss under different rainfall intensities (low, 30 mm h-1; middle, 60 mm h-1; high, 90 mm h-1). The results showed that the time interval from the beginning of rain to the occurrence of runoff (time to runoff, Tr) was negatively correlated with "rainfall intensity" (Ri) (P<0.01) but unaffected by soil moisture. Different rainfall intensities had no effect on the runoff coefficient (the ratio of the runoff volume over the precipitation, 0.14-0.17). The N and P loss concentrations in the nutrient discharge followed a power-function relationship that decreased over time (P<0.01), and the peak nutrient concentration appeared during the initial runoff period (0-5 min). The N and P loss rates were the highest during the middle-to-late discharge period (15-30 min) for all intensities. In terms of cumulative nutrient losses, the amounts of TN lost were similar for all rainfall intensities, while TP significantly increased with intensity. The results revealed that nitrate-nitrogen (NOX--N) and particulate phosphorus (PP) were the predominant forms of N and P losses. Overall, during the initial runoff period, nutrient concentration peaks, whereas the nutrient loss rate is the highest during the middle-late phase of the phenomenon.


Asunto(s)
Oryza , Triticum , China , Nitrógeno/análisis , Nutrientes , Fósforo/análisis , Lluvia , Rotación , Estaciones del Año , Suelo , Movimientos del Agua
14.
Environ Sci Pollut Res Int ; 28(31): 42082-42092, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33792846

RESUMEN

A mechanical harvesting technology based on coupling flocculation with a rotary drum filter (RDF, 35-µm) was applied to remove cyanobacterial blooms and produce clean water in Lake Caohai, a sub-lake of Lake Dianchi (Kunming, China). After treatment with a shipboard RDF and cationic polyacrylamide (CPAM, 0.5-2 mg/L) flocculation, > 95% of cyanobacterial biomass was removed. The chlorophyll-a (Chl-a) concentration and turbidity in the effluent were < 8 µg/L and < 3 NTU, respectively. Nutrient concentrations were also markedly reduced, with a permanganate index (PI) of < 2 mg/L and total phosphorus concentration of < 20 µg/L. The total nitrogen concentration was reduced from 2.75 to 1.65 mg/L, and most of the residual nitrogen was nitrate. Although powerful for the removal of suspended particles and an enhanced water transparency, the combined technology showed no significant reduction in inorganic nutrients and only a slight reduction in dissolved organic matter (DOM). The concentrations of protein and polysaccharide were significantly reduced, while that of humic matter did not change during the process. After flushing with the effluent of the RDF, a 20,000-m3 enclosure of lake water became clear when the volume of the effluent was 1.8 times that of the water enclosure. The electrical energy per order (EE/O) was calculated to be 0.053kWh/m3, which is lower than that of transferring water from more than 10 km away (0.058 kWh/m3). Thus, a shipboard RDF coupled with CPAM flocculation is a promising approach to remove harmful cyanobacterial blooms and improve the water environment of eutrophic lakes.


Asunto(s)
Cianobacterias , Eutrofización , China , Floculación , Lagos , Fósforo/análisis , Agua
15.
Plant Cell ; 33(5): 1615-1632, 2021 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-33793860

RESUMEN

TARGET OF RAPAMYCIN (TOR) is a conserved eukaryotic Ser/Thr protein kinase that coordinates growth and metabolism with nutrient availability. We conducted a medium-throughput functional genetic screen to discover essential genes that promote TOR activity in plants, and identified a critical regulatory enzyme, cytosolic phosphoribosyl pyrophosphate (PRPP) synthetase (PRS4). PRS4 synthesizes cytosolic PRPP, a key upstream metabolite in nucleotide synthesis and salvage pathways. We found that prs4 knockouts are embryo-lethal in Arabidopsis thaliana, and that silencing PRS4 expression in Nicotiana benthamiana causes pleiotropic developmental phenotypes, including dwarfism, aberrant leaf shape, and delayed flowering. Transcriptomic analysis revealed that ribosome biogenesis is among the most strongly repressed processes in prs4 knockdowns. Building on these results, we discovered that TOR activity is inhibited by chemical or genetic disruption of nucleotide biosynthesis, but that this effect can be reversed by supplying plants with nucleobases. Finally, we show that TOR transcriptionally promotes nucleotide biosynthesis to support the demands of ribosomal RNA synthesis. We propose that TOR coordinates ribosome biogenesis with nucleotide availability in plants to maintain metabolic homeostasis and support growth.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Nucleótidos/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Ribosomas/metabolismo , Arabidopsis/embriología , Arabidopsis/genética , Citosol/metabolismo , Silenciador del Gen , Genes de Plantas , Fósforo/metabolismo , Células Vegetales/metabolismo , Desarrollo de la Planta , Purinas/biosíntesis , Pirimidinas/biosíntesis , Tabaco/metabolismo , Transcriptoma/genética
16.
Sci Rep ; 11(1): 9268, 2021 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-33927234

RESUMEN

The heart's geometry and its metabolic activity vary over the cardiac cycle. The effect of these fluctuations on phosphorus (31P) magnetic resonance spectroscopy (MRS) data quality and metabolite ratios was investigated. 12 healthy volunteers were measured using a 7 T MR scanner and a cardiac 31P-1H loop coil. 31P chemical shift imaging data were acquired untriggered and at four different times during the cardiac cycle using acoustic triggering. Signals of adenosine-triphosphate (ATP), phosphocreatine (PCr), inorganic phosphate (Pi) and 2,3-diphosphoglycerate (2,3-DPG) and their fit quality as Cramér-Rao lower bounds (CRLB) were quantified including corrections for contamination by 31P signals from blood, flip angle, saturation and total acquisition time. The myocardial filling factor was estimated from cine short axis views. The corrected signals of PCr and [Formula: see text]-ATP were higher during end-systole and lower during diastasis than in untriggered acquisitions ([Formula: see text]). Signal intensities of untriggered scans were between those with triggering to end-systole and diastasis. Fit quality of PCr and [Formula: see text]-ATP peaks was best during end-systole when blood contamination of ATP and Pi signals was lowest. While metabolite ratios and pH remained stable over the cardiac cycle, signal amplitudes correlated strongly with myocardial voxel filling. Triggering of cardiac 31P MRS acquisitions improves signal amplitudes and fit quality if the trigger delay is set to end-systole. We conclude that triggering to end-systole is superior to triggering to diastasis.


Asunto(s)
Adenosina Trifosfato/metabolismo , Corazón/fisiología , Imagen por Resonancia Magnética/métodos , Espectroscopía de Resonancia Magnética/métodos , Miocardio/metabolismo , Fósforo/análisis , Adulto , Femenino , Humanos , Masculino , Adulto Joven
17.
Arch Microbiol ; 203(5): 2551-2561, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33683396

RESUMEN

Phosphate-solubilizing (PS) and phosphate-mineralizing (PM) bacteria are considered vital for augmenting the plant growth through phosphorus mobilization and plant growth-promoting attributes. In the present study, a rhizospheric bacterium was isolated from the virgin land of Punjab, India and identified as 'Myroides gitamensis' BSH-3 through 16S rRNA sequencing. 'M. gitamensis' showed potential halo zone on Pikovskaya agar. The novelty of the study lies in the fact that plant growth-promoting potential of 'M. gitamensis' has not been studied earlier. It was able to solubilize 17.53-106.66 µg/mL of tricalcium phosphate and demonstrated a promising potential of mineralizing sodium phytate corresponding to 44.6-94.70 µg/mL at 28 °C. Variable PS and PM activity was observed at temperature range of 15-42 °C with the maximum activity observed at 28 °C after 96 h of incubation. The nitrogen fixation ability, hydrogen sulfide production, cellulose hydrolysis test and chitin degradation was found to be negative. High indole acetic acid (42.82 µg/mL), gibberellic acid (72.93 µg/mL), ammonia (22.58 µg/mL) production, phytase activity (0.49 pi/mL/min) and comparable amount of siderophore (28.55%) and acid phosphate activity (0.606 µM p-nitrophenol/ml/min) was shown by 'M. gitamensis'. Inoculation of wheat with 'M. gitamensis' in pot experiment showed increased shoot and root length by 30.58% and 38.32%. Fresh weight and dry weight was increased by 45.74% and 67.81%, respectively, compared to uninoculated control. These results demonstrate that 'M. gitamensis' has promising PS, PM and plant growth-promoting attributes to be used as a bio-inoculant to enhance plant growth and soil fertility.


Asunto(s)
Flavobacteriaceae/metabolismo , Fosfatos/metabolismo , Microbiología del Suelo , Triticum/crecimiento & desarrollo , Amoníaco/metabolismo , Fosfatos de Calcio/metabolismo , Flavobacteriaceae/aislamiento & purificación , India , Ácidos Indolacéticos/metabolismo , Fijación del Nitrógeno , Fósforo/metabolismo , Desarrollo de la Planta , Raíces de Plantas/crecimiento & desarrollo , ARN Ribosómico 16S/genética
18.
Pharm Dev Technol ; 26(5): 582-591, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33729906

RESUMEN

Mesoporous silica nanoparticles (MSNs) gained significant attention, particularly in the pharmaceutical field. Folic acid (FA) shows marked promise as a targeting agent for its specific interaction with the folate receptor. This receptor is over-expressed on the cell surface of several cancerous cells like breast cancer. Polyethylene glycol (PE), as well as polypropylene glycol (PEG), is used to decorate nanoparticles to improve their biodistribution. Moreover, carboxymethyl beta-cyclodextrin (CM-ß-CD), is used as a complexation molecule. In this study, we described the chemical synthesis, in vitro drug release and antiproliferative activity of doxorubicin-loaded/decorated MSNs further coupled with FA in two conditions: chemically bound or as a complex with CM-ß-CD. Fourier Transform Infrared Spectroscopy with Transmission Electron Microscopy confirmed the successful surface change. Dynamic Light Scattering confirmed the change in surface characters like zeta potential, polydispersity index (PI), and size. PI improved from 0.58 to 0.23 while the size enlarged from 200 to 348 and 532 nm. Functionalized nanoparticles demonstrated more significant drug entrapment with (97%) while undecorated MSNs only showed (63%). Accordingly, we effectively synthesized FA-PEG2000-MSNs with IC50: 0.015 mg/mL targeting HeLa cells. This approach may allow potential applications as a drug delivery system in cancer chemotherapy.HighlightsMesoporous silica nanoparticles (MSNs) with a carboxylic acid or amine surface group can be successfully decorated with long-chain hydrophilic polymer via an amide bond.Carboxymethyl-ß-cyclodextrin coupled with long-chain polymer as host to form a complex with targeting molecule folic acid.Folic acid can be anchored directly to a polymer coat.TEM; DLS and FTIR confirmed the surface modification.The drug encapsulation efficiency; cytotoxicity and selectivity of functionalized nanoparticles with PEG and conjugated with FA were the best.Chemical modification has improved cytotoxicity of doxorubicin and selectivity against Hela cells.


Asunto(s)
Antibióticos Antineoplásicos/administración & dosificación , Doxorrubicina/administración & dosificación , Sistemas de Liberación de Medicamentos , Nanopartículas , Antibióticos Antineoplásicos/farmacología , Doxorrubicina/farmacología , Portadores de Fármacos/química , Liberación de Fármacos , Dispersión Dinámica de Luz , Ácido Fólico/química , Células HeLa , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Concentración 50 Inhibidora , Tamaño de la Partícula , Polietilenglicoles/química , Polímeros , Porosidad , Glicoles de Propileno , Dióxido de Silicio/química
19.
J Pharm Pharmacol ; 73(5): 641-652, 2021 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-33772289

RESUMEN

OBJECTIVES: The current study was focused on preparing curcumin (CUR) supersaturated self-nano-emulsion (PI-CUR-SNEDDS) using hydrophilic polymer and to study the influence of polymer precipitation inhibitor on the physicochemical and biopharmaceutical properties of the PI-CUR-SNEDDS. METHODS: PI-CUR-SNEDDS were prepared using hydrophilic polymer in order to maintain the supersaturation of CUR in nano-emulsion solution, artificial gastrointestinal fluid (AGF), and the precipitates formed, and characterised by in vitro dispersion tests, in vitro intestinal absorption and in vivo pharmacokinetic and compared with CUR-SNEDDS. KEY FINDINGS: PI-CUR-SNEDDS prepared with 2% hydroxypropyl methylcellulose 55-60 (HPMC55-60) as precipitation inhibitor (PI) significantly improved the viscosity, physical stability and CUR's equilibrium solubility of nanoemulsion. HPMC55-60 and CUR interact in AGF through intermolecular interactions, form hydrogen bonds, and produce amorphous precipitates. Compared with CUR-SNEDDS, the proportion of CUR in the hydrophilic phase increased by about 3-fold, and apparent permeability coefficient (Papp) in duodenum, jejunum, ileum, and colon increased by 2.30, 3.65, 1.54 and 2.08-fold, respectively, and the area under the plasma concentration-time curve0-12h of PI-CUR-SNEDDS also increased by 3.50-fold. CONCLUSIONS: Our results suggested that HPMC55-60 maintained the CUR supersaturation state by forming hydrogen bonds with CUR, increasing the solution's viscosity and drug solubilisation, thus improving the absorption and bioavailability of CUR.


Asunto(s)
Curcumina/administración & dosificación , Curcumina/farmacocinética , Sistemas de Liberación de Medicamentos/métodos , Administración Oral , Animales , Disponibilidad Biológica , Liberación de Fármacos , Emulsiones/química , Interacciones Hidrofóbicas e Hidrofílicas , Derivados de la Hipromelosa/administración & dosificación , Derivados de la Hipromelosa/farmacología , Absorción Intestinal , Tamaño de la Partícula , Polímeros/administración & dosificación , Polímeros/farmacología , Ratas Sprague-Dawley , Solubilidad
20.
Toxicol In Vitro ; 73: 105140, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33705896

RESUMEN

Due to advancement in nanomaterials and increasing use of functionalized gold nanoclusters (AuNCs) in different biomedical applications, better understanding of their potential cytotoxicity is necessary. Interactions of ultra-small fluorescent AuNCs with mammalian cells remains up to this day poorly understood, therefore, cytotoxic evaluation of thoroughly characterized ca. 2.5 nm spherical water-soluble 11-mercaptoundecanoic acid coated AuNCs (AuNC@M) with diverse fluorescent properties in variety of mammalian cancer cell lines was performed. Cell viability was assessed by traditional MTT assay and xCELLigence real time cell analyzer. Cell apoptosis was evaluated via an Annexin V-FITC/propidium iodide (PI) assay. Confocal fluorescence imaging confirmed that tested AuNC@M entered live cells and were homogeneously distributed in their cytoplasm. The results suggested that the cytotoxicity of tested nanoclusters was very low, or near the control level at concentrations 0.1 and 0.5 mg/mL in the cell lines after 24 h exposition. The purity of tested AuNC@M had no relevant effect on cell viability and no differences were observed after 24 h in our study. The low toxicity toward cancer cells further strengthens our view that AuNC@M are promising label-free fluorescent probes for bio-labelling and bio-imaging, or they can even serve as platforms for antitumor drug delivery systems.


Asunto(s)
Ácidos Grasos/administración & dosificación , Colorantes Fluorescentes/administración & dosificación , Oro/administración & dosificación , Nanoestructuras/administración & dosificación , Compuestos de Sulfhidrilo/administración & dosificación , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Diagnóstico por Imagen , Sistemas de Liberación de Medicamentos , Ácidos Grasos/química , Fluorescencia , Colorantes Fluorescentes/química , Oro/química , Humanos , Ratones , Microscopía Confocal , Microscopía Electrónica de Transmisión , Nanoestructuras/química , Nanoestructuras/ultraestructura , Neoplasias/diagnóstico por imagen , Compuestos de Sulfhidrilo/química
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