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1.
Sci Total Environ ; 929: 172472, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38642760

RESUMEN

High reactive nitrogen (N) emissions due to anthropogenic activities in China have led to an increase in N deposition and ecosystem degradation. The Chinese government has strictly regulated reactive N emissions since 2010, however, determining whether N deposition has reduced requires long-term monitoring. Here, we report the patterns of N deposition at a rural forest site (Qingyuan) in northeastern China over the last decade. We collected 456 daily precipitation samples from 2014 to 2022 and analysed the temporal dynamics of N deposition. NH4+-N, NO3--N, and total inorganic N (TIN) deposition ranged from 10.5 ± 3.5 (mean ± SD), 6.1 ± 1.6, and 16.6 ± 4.7 kg N ha-1 year-1, respectively. Over the measurement period, TIN deposition at Qingyuan decreased by 55 %, whereas that in comparable sites in East Asia declined by 14-34 %. We used a random forest model to determine factors influencing the deposition of NH4+-N, NO3--N, and TIN during the study period. NH4+-N deposition decreased by 60 % because of decreased agricultural NH3 emissions. Furthermore, NO3--N deposition decreased by 42 %, due to reduced NOx emissions from agricultural soil and fossil fuel combustion. The steep decline in N deposition in northeastern China was attributed to reduced coal consumption, improved emission controls on automobiles, and shifts in agricultural practices. Long-term monitoring is needed to assess regional air quality and the impact of N emission control regulations.

2.
Insect Biochem Mol Biol ; 149: 103845, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36165873

RESUMEN

Chitin, the major structural polysaccharide in arthropods such as insects and mites, is a linear polymer of N-acetylglucosamine units. The growth and development of insects are intimately coupled with chitin biosynthesis. The membrane-bound ß-glycosyltransferase chitin synthase is known to catalyze the key polymerization step of N-acetylglucosamine. However, the additional proteins that might assist chitin synthase during chitin biosynthesis are not well understood. Recently, fatty acid binding protein (Fabp) has been suggested as a candidate that interacts with the chitin synthase Krotzkopf verkehrt (Kkv) in Drosophila melanogaster. Here, using split-ubiquitin membrane yeast two-hybrid and pull-down assays, we have demonstrated that the Fabp-B splice variant physically interacts with Kkv in vitro. The global knockdown of Fabp in D. melanogaster using RNA interference (RNAi) induced lethality at the larval stage. Moreover, in tissue-specific RNAi experiments, silenced Fabp expression in the epidermis and tracheal system caused a lethal larval phenotype. Fabp knockdown in the wings resulted in an abnormal wing development and uneven cuticular surface. In addition to reducing the chitin content in the first longitudinal vein of wings, Fabp silencing also caused the loss of procuticle laminate structures. This study revealed that Fabp plays an important role in chitin synthesis and contributes to a comprehensive understanding of the complex insect chitin biosynthesis.


Asunto(s)
Quitina Sintasa , Drosophila melanogaster , Acetilglucosamina , Animales , Quitina , Quitina Sintasa/genética , Drosophila melanogaster/genética , Proteínas de Unión a Ácidos Grasos/genética , Insectos , Larva/genética , Interferencia de ARN , Ubiquitinas/genética
3.
AAPS PharmSciTech ; 23(6): 193, 2022 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-35821540

RESUMEN

This study aimed to prepare effervescent tablets of traditional Chinese medicine Xianganfang with fresh juice using a semi-solid 3D printer with three cartridge holders to seperate acid and alkali source by drug paste through model design to avoid sticking impact and premature effervescence during the tableting in the conventional preparation process. The powder of Xianganfang including fresh juice of Phyllanthus emblica and licorice extract was obtained by vacuum freeze-drying with 50% mannitol as cryoprotectant. Then, the formulation of 3D-printed effervescent tablets was investigated. Further 5% HPMC hydroalcoholic gel was mixed with sodium bicarbonate and freeze-dried Xianganfang powder to prepare alkali source and drug paste respectively while 30% PVP ethanol solution was mixed with tartaric acid to prepare acid source paste; these three pastes had good printability. The pastes of drug, acid, and alkali were loaded into three syringe cartridges separately and numbered as "3," "5," and "7," according to cartridge holders of the 3D printer, and printed in the order of "537,353,735" for separating acid and alkali by drug to avoid premature effervescence. And the basic printing parameters were optimized. The tablets were evaluated by the appearance, tablet weight variation, hardness, disintegration time, friability, pH, and stability. The physicochemical properties all conformed to the Chinese Pharmacopoeia 2020 edition. The content of the active ingredient gallic acid was 0.769 ± 0.019 mg/g. This study provided a new method to prepare effervescent tablets of traditional Chinese medicine with fresh juice using 3D printing technology.


Asunto(s)
Excipientes , Tecnología Farmacéutica , Álcalis , Liberación de Fármacos , Excipientes/química , Polvos , Comprimidos/química , Tecnología Farmacéutica/métodos
4.
Insect Biochem Mol Biol ; 145: 103783, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35525402

RESUMEN

The biogenesis of chitin, a major structural polysaccharide found in the cuticle and peritrophic matrix, is crucial for insect growth and development. Chitin synthase, a membrane-integral ß-glycosyltransferase, has been identified as the core of the chitin biogenesis machinery. However, a yet unknown number of auxiliary proteins appear to assist in chitin biosynthesis, whose precise function remains elusive. Here, we identified a sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), in the fruit fly Drosophila melanogaster, as a chitin biogenesis-associated protein. The physical interaction between DmSERCA and epidermal chitin synthase (Krotzkopf verkehrt, Kkv) was demonstrated and analyzed using split-ubiquitin membrane yeast two-hybrid, bimolecular fluorescent complementation, pull-down, and immunoprecipitation assays. The interaction involves N-terminal regions (aa 48-81 and aa 247-33) and C-terminal regions (aa 743-783 and aa 824-859) of DmSERCA and two N-terminal regions (aa 121-179 and aa 369-539) of Kkv, all of which are predicted be transmembrane helices. While tissue-specific knock-down of DmSERCA in the epidermis caused larval and pupal lethality, the knock-down of DmSERCA in wings resulted in smaller and crinkled wings, a significant decrease in chitin deposition, and the loss of chitin lamellar structure. Although DmSERCA is well-known for its role in muscular contraction, this study reveals a novel role in chitin synthesis, contributing to our knowledge on the machinery of chitin biogenesis.


Asunto(s)
Quitina Sintasa , Drosophila , Secuencia de Aminoácidos , Animales , Quitina/metabolismo , Quitina Sintasa/genética , Quitina Sintasa/metabolismo , Drosophila/metabolismo , Drosophila melanogaster/metabolismo
5.
Nat Commun ; 13(1): 880, 2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-35169118

RESUMEN

The impacts of enhanced nitrogen (N) deposition on the global forest carbon (C) sink and other ecosystem services may depend on whether N is deposited in reduced (mainly as ammonium) or oxidized forms (mainly as nitrate) and the subsequent fate of each. However, the fates of the two key reactive N forms and their contributions to forest C sinks are unclear. Here, we analyze results from 13 ecosystem-scale paired 15N-labelling experiments in temperate, subtropical, and tropical forests. Results show that total ecosystem N retention is similar for ammonium and nitrate, but plants take up more labelled nitrate ([Formula: see text]%) ([Formula: see text]) than ammonium ([Formula: see text]%) while soils retain more ammonium ([Formula: see text]%) than nitrate ([Formula: see text]%). We estimate that the N deposition-induced C sink in forests in the 2010s  is [Formula: see text] Pg C yr-1, higher than previous estimates because of a larger role for oxidized N and greater rates of global N deposition.


Asunto(s)
Compuestos de Amonio/análisis , Secuestro de Carbono/fisiología , Restauración y Remediación Ambiental , Bosques , Nitratos/análisis , Árboles/metabolismo , Ambiente , Isótopos de Nitrógeno/química , Óxidos de Nitrógeno/análisis , Suelo/química
6.
J Ethnopharmacol ; 288: 114995, 2022 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-35032584

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: The dried flower bud of Syzygium aromaticum (L.) Merr. & L.M Perry (S. aromaticum) (Myrtaceae), also known as clove, was used in Traditional Chinese Medicine (TCM) to aid gastrointestinal function and treat stomach disorders including vomiting, flatulence and nausea. And it is a food homology medicine which is a promising candidate for H. pylori treatment. H. pylori is a Gram-negative bacterium that infects approximately 50% of the human population worldwide, which is closely related to multiple gastric diseases, including gastric cancer. However, there are still no sufficient studies on the anti-H. pylori activity of S. aromaticum, especially for the mechanism of action. AIM OF STUDY: This study aimed to study the antibacterial activities of S. aromaticum extracts on both antibiotic-sensitive and -resistant H. pylori strains, and to explore the underlying mechanisms of action. MATERIALS AND METHODS: The S. aromaticum extracts were obtained by heat reflux extraction and lyophilized to powder form. The phytochemical analyses were performed by High-performance liquid chromatography (HPLC) and UPLC-electrospray ionization mass spectrometry (ESI-MS). In vitro anti-H. pylori activity was evaluated by broth microdilution method. Mechanism of action studies included morphological observation using electron microscopy, determination of expression of virulence genes by reverse transcription quantitative polymerase chain reaction (RT-qPCR), genes expression profile identification by transcriptomic analysis, and exploration of anti-H. pylori infection mechanisms by network pharmacology analysis and western blotting validation. RESULTS: The S. aromaticum extracts, aqueous extract (AE) and 75% hydroalcoholic extract (HE), exerted significant antibacterial activities against both antibiotic-sensitive and -resistant H. pylori strains with MICs of 160∼320 µg/ml, without developing drug resistance. Among them, AE was bactericide to all the tested strains with MBCs of less than 4MIC, while HE was merely bacteriostatic to most of the tested strains with MBCs of 2MIC∼16MIC. Besides, they showed no antagonistic effects in combination with clarithromycin, metronidazole, levofloxacin, and amoxicillin. Additionally, these extracts altered the morphology and ultrastructure and down-regulated the virulence genes expression of H. pylori. And transcriptomic analysis showed that they regulated genes expression of multiple H. pylori biological processes, including tricarboxylic acid cycle (TAC) and pyruvate metabolic pathways. Furthermore, these extracts combated the abnormal activation of PI3K-Akt and MAPK signaling pathways caused by H. pylori infection. CONCLUSIONS: Overall, the present study firstly analyzed the chemical compositions of S. aromaticum extracts, and then confirmed their activities on both antibiotic-sensitive and -resistant H. pylori strains. In addition, the mechanisms of action of S. aromaticum extracts against H. pylori were found to be destroying the bacterial structure, down-regulating the expression of virulence genes, and interfering TAC and pyruvate metabolic pathways. Finally, S. aromaticum extracts were found to combated the abnormal activation of PI3K-Akt and MAPK signaling pathways to treat H. pylori infection. This study should accelerate further research and application of S. aromaticum against H. pylori infection.


Asunto(s)
Antibacterianos/farmacología , Helicobacter pylori/efectos de los fármacos , Extractos Vegetales/farmacología , Syzygium/química , Antibacterianos/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Farmacorresistencia Bacteriana , Regulación Bacteriana de la Expresión Génica , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Helicobacter pylori/patogenicidad , Humanos , Pruebas de Sensibilidad Microbiana , Farmacología en Red , Espectrometría de Masa por Ionización de Electrospray , Virulencia/genética
7.
Insect Biochem Mol Biol ; 141: 103718, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34982980

RESUMEN

Chitin is an aminopolysaccharide present in insects as a major structural component of the cuticle. However, current knowledge on the chitin biosynthetic machinery, especially its constituents and mechanism, is limited. Using three independent binding assays, including co-immunoprecipitation, split-ubiquitin membrane yeast two-hybrid assay, and pull-down assay, we demonstrate that choline transporter-like protein 2 (Ctl2) interacts with krotzkopf verkehrt (kkv) in Drosophila melanogaster. The global knockdown of Ctl2 by RNA interference (RNAi) induced lethality at the larval stage. Tissue-specific RNAi to silence Ctl2 in the tracheal system and in the epidermis of the flies resulted in lethality at the first larval instar. The knockdown of Ctl2 in wings led to shrunken wings containing accumulated fluid. Calcofluor White staining demonstrated reduced chitin content in the first longitudinal vein of Ctl2 knockdown wings. The pro-cuticle, which was thinner compared to wildtype, exhibited a reduced number of chitin laminar layers. Phylogenetic analyses revealed orthologues of Ctl2 in different insect orders with highly conserved domains. Our findings provide new insights into cuticle formation, wherein Ctl2 plays an important role as a chitin-synthase interacting protein.


Asunto(s)
Quitina Sintasa/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Proteínas de Transporte de Membrana/genética , Alas de Animales/crecimiento & desarrollo , Secuencia de Aminoácidos , Animales , Quitina Sintasa/química , Quitina Sintasa/metabolismo , Proteínas de Drosophila/química , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crecimiento & desarrollo , Drosophila melanogaster/metabolismo , Epidermis/crecimiento & desarrollo , Larva/genética , Larva/crecimiento & desarrollo , Proteínas de Transporte de Membrana/química , Proteínas de Transporte de Membrana/metabolismo , Filogenia , Alineación de Secuencia
8.
J Ethnopharmacol ; 283: 114578, 2022 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-34464702

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Canarium album Raeusch. belongs to the Burseraceae family. Its ripe fruits, known as Qing Guo (QG) in Traditional Chinese Medicine (TCM), are used to treat sore throat, cough, and fish or crab poisoning. QG was reported to have antibacterial activity, and it exerted excellent anti-Helicobacter pylori (H. pylori) activity in our screening of abundant TCM. However, few studies have reported its anti-H. pylori activity and mechanism. AIM OF STUDY: The commonly used eradication therapies for H. pylori infection are antibiotic-based therapies. With the increasing antibiotic resistance of H. pylori, interest in finding alternative therapies has been aroused. This study investigated the phytochemistry profile, in vitro anti-H. pylori activity and possible anti-bacterial mechanism of QG extracts. MATERIALS AND METHODS: QG extracts were obtained by heat reflux extraction, ultrasonic extraction or liquid-liquid extraction with different solvents. The quantitative and qualitative phytochemical analyses were performed by colorimetric determination, high-performance liquid chromatography (HPLC), and UPLC-electrospray ionization mass spectrometry (ESI-MS). In vitro anti- H. pylori activity was assessed by broth micro-dilution method. Mechanism of action studies included morphological observation using electron microscopy, urease inhibition assay and determination of expression of virulence genes by RT-qPCR. RESULTS: All QG extracts especially ethyl acetate extract (QGEAE) were rich in phenolic components, with the minimum inhibitory concentrations (MICs) on H.pylori of 39-625 µg/ml and minimum bactericidal concentrations (MBCs) of 78-1250 µg/ml. Both aqueous extract (QGAE) and QGEAE could induce the morphological and structural changes of H. pylori, inhibit urease activity with IC50 of 1093 µg/ml and 332.90 µg/ml, respectively, and down-regulate the virulence genes, such as vacA and cagA. CONCLUSIONS: QG may exhibit in vitro anti-H. pylori activity by inhibiting growth, destroying the bacterial structure and down-regulating the expression of virulence factors. Moreover, QG is the homology of food and TCM, which can be considered as a safe and convenient agent against H. pylori infection.


Asunto(s)
Antibacterianos/farmacología , Burseraceae/química , Helicobacter pylori/efectos de los fármacos , Extractos Vegetales/farmacología , Antibacterianos/administración & dosificación , Antibacterianos/aislamiento & purificación , Frutas , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/microbiología , Concentración 50 Inhibidora , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/administración & dosificación
9.
Environ Sci Pollut Res Int ; 29(5): 7127-7152, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34472030

RESUMEN

Resource integration of coal enterprises is conducive to reducing pollution and carbon emissions, thus alleviating environmental problems such as global warming. Government regulation has a great influence on enterprise behavior. Therefore, it is necessary to analyze the strategies of government and coal enterprises in resource integration. Based on the perspective of government regulation, this paper discusses how to guide and restrict coal enterprises to conduct resource integration behavior, and whether the government supervises this behavior. First, through empirical research, government regulations of coal enterprises are given practical policy implications. Second, using evolutionary game and simulation technology, from the perspective of government regulation, we explore the complex behavioral interaction mechanism between the dominant and inferior coal enterprises, the mechanism between the government and coal enterprises, and analyze the impact of key factors on the dynamic evolution process. Finally, the sensitivity analysis of the selected parameters is discussed in details, which provides useful decision-making suggestions for the government and enterprises. In addition, this paper further analyzes the impact of different government policies on coal enterprises' green innovation strategies. Results demonstrate that (1) when the power gap between enterprises is large, the probability of dominant enterprises choosing resource integration converges to 1, while the probability of inferior enterprises converges to 0. Therefore, government regulations are invalid for inferior enterprises; (2) the combination of government regulations can help improve the efficiency of coal enterprises' strategic choices. With the increase in the intensity of government rewards and punishments, the probability of enterprise resource integration evolves from 0 to 1; (3) excessive government regulations make the choice between the government and coal companies tend to swing, because the probability of the two is between 0 and 1. Therefore, excessive government regulations cannot effectively achieve resource integration and government regulation. (4) The government subsidy strategy is less effective than the government's pollution penalty strategy in promoting the green innovation of enterprises. Our research shows that the government should choose different policy combinations and intensities to regulate resource integration according to the market power of coal enterprises, which provides theoretical reference and practical guidance for the government to regulate corporate resource integration behavior.


Asunto(s)
Teoría del Juego , Regulación Gubernamental , China , Carbón Mineral , Contaminación Ambiental , Gobierno
10.
Environ Pollut ; 286: 117312, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-33992903

RESUMEN

Nitric oxide (NO) plays a critical role in atmospheric chemistry and also is a precursor of nitrate, which affects particle matter formation and nitrogen deposition. Agricultural soil has been recognized as a main source of atmospheric NO. However, quantifying the NO fluxes emitted from croplands remains a challenge and in situ long-term measurements of NO are still limited. In this study, we used an automated sampling system to measure NO fluxes with a high temporal resolution over two years (April 2017 to March 2019) from a rainfed maize field in the Northeast China. The cumulative annual NO emissions were 8.9 and 2.3 kg N ha-1 in year 1 (April 2017 to March 2018) and year 2 (April 2018 to March 2019), respectively. These interannual differences were largely related to different weather conditions encountered. In year 1, a month-long drought before and after the seeding and fertilizing reduced plant N uptake and dramatically increased soil N concentration. The following moderate rainfalls promoted large amount of NO emissions, which remained high until late September. The NO fluxes in both years showed clearer seasonal patterns, being highest after fertilizer application in summer, and lowest in winter. The seasonal patterns of NO fluxes were mainly controlled by soil available N concentrations and soil temperatures. The contribution of NO fluxes during the spring freeze-thaw in both years was no more than 0.2% of the annual NO budget, indicating that the freeze-thaw effect on agricultural NO emissions was minimal. In addition, with high-resolution monitoring, we found that soil not only act as a NO source but also a sink. Long-term and high-resolution measurements help us better understand the diurnal, seasonal, and annual dynamics of NO emissions, build more accurate models and better estimate global NO budget and develop more effective policy responses to global climate change.


Asunto(s)
Suelo , Zea mays , Agricultura , China , Fertilizantes/análisis , Óxido Nítrico , Óxido Nitroso/análisis , Estaciones del Año
11.
Chin Med ; 16(1): 33, 2021 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-33865425

RESUMEN

BACKGROUND: Helicobacter pylori (H. pylori) infection has become an international public health problem, and antibiotic-based triple or quadruple therapy is currently the mainstay of treatment. However, the effectiveness of these therapies decreases due to resistance to multiple commonly used antibiotics. Sanguisorba officinalis L. (S. officinalis), a traditional Chinese medicine clinically used for hemostasis and treatment of diarrhea, has various pharmacological activities. In this study, in vitro antimicrobial activity was used for the preliminary evaluation of S. officinalis against H. pylori. And a pharmacology analysis approach was also utilized to elucidate its underlying mechanisms against H. pylori infection. METHODS: Micro-broth dilution method, agar dilution method, checkerboard assay, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used for the assessment of anti-bacterial activity. Active ingredients screening, GO analysis, KEGG analysis, construction of PPI network, molecular docking, and RT-qPCR were used to elucidate the underlying pharmacological mechanisms of S. officinalis against H. pylori infection. RESULTS: The minimum inhibitory concentration (MIC) values of S. officinalis against multiple H. pylori strains including clinically isolated multi-drug resistant (MDR) strains were ranging from 160 to 320 µg/ml. These results showed that S. officinalis had additive interaction with four commonly used antibiotics and could exert antibacterial effect by changing the morphology of bacteria without developing drug resistance. Through network pharmacology analysis, 8 active ingredients in S. officinalis were screened out for subsequent studies. Among 222 putative targets of S. officinalis, 49 targets were identified as potential targets for treatment of H. pylori infection. And these 49 targets were significantly enriched in GO processes such as protein kinase B signaling, protein kinase activity, protein kinase binding, and KEGG pathways such as Pathways in cancer, MicroRNAs in cancer, and TNF signaling pathway. Protein-protein interaction analysis yielded 5 core targets (AKT1, VEGFA, EGFR, SRC, CCND1), which were validated by molecular docking and RT-qPCR. CONCLUSIONS: Overall, this study confirmed the in vitro inhibitory activity of S. officinalis against H. pylori and explored the possible pharmacological mechanisms, laying the foundation for further research and clinical application.

12.
Glob Chang Biol ; 27(10): 2076-2087, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33484031

RESUMEN

The effects of nitrogen (N) deposition on forests largely depend on its fate after entering the ecosystem. While several studies have addressed the forest fate of N deposition using 15 N tracers, the long-term fate and redistribution of deposited N in tropical forests remains unknown. Here, we applied 15 N tracers to examine the fates of deposited ammonium ( NH 4 + ) and nitrate ( NO 3 - ) separately over 3 years in a primary and a secondary tropical montane forest in southern China. Three months after 15 N tracer addition, over 60% of 15 N was retained in the forests studied. Total ecosystem retention did not change over the study period, but between 3 months and 3 years following deposition 15 N recovery in plants increased from 10% to 19% and 13% to 22% in the primary and secondary forests, respectively, while 15 N recovery in the organic soil declined from 16% to 2% and 9% to 2%. Mineral soil retained 50% and 35% of 15 N in the primary and secondary forests, with retention being stable over time. The total ecosystem retention of the two N forms did not differ significantly, but plants retained more 15 NO 3 - than 15 NH 4 + and the organic soil more 15 NH 4 + than NO 3 - . Mineral soil did not differ in 15 NH 4 + and 15 NO 3 - retention. Compared to temperate forests, proportionally more 15 N was distributed to mineral soil and plants in these tropical forests. Overall, our results suggest that atmospherically deposited NH 4 + and NO 3 - is rapidly lost in the short term (months) but thereafter securely retained within the ecosystem, with retained N becoming redistributed to plants and mineral soil from the organic soil. This long-term N retention may benefit tropical montane forest growth and enhance ecosystem carbon sequestration.


Asunto(s)
Ecosistema , Nitrógeno , China , Bosques , Suelo , Árboles
13.
New Phytol ; 229(6): 3184-3194, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33226653

RESUMEN

Conifers are considered to prefer to take up ammonium (NH4+ ) over nitrate (NO3- ). However, this conclusion is mainly based on hydroponic experiments that separate roots from soils. It remains unclear to what extent mature conifers can use nitrate compared to ammonium under field conditions where both roots and soil microbes compete for nitrogen (N). We conducted an in situ whole mature tree nitrogen-15 (15 N) labeling experiment (15 NH4+ vs 15 NO3- ) over 15 d to quantify ammonium and nitrate uptake and assimilation rates in four 40-yr-old monoculture coniferous plantations (Pinus koraiensis, Pinus sylvestris, Picea koraiensis and Larix olgensis, respectively). For the whole tree, 15 NO3- contributed 39% to 90% to total 15 N tracer uptake among four plantations during the study period. At day 3, the 15 NO3- accounted for 77%, 64%, 62% and 59% by Larix olgensis, Pinus koraiensis, Pinus sylvestris and Picea koraiensis, respectively. Our study indicates that mature coniferous trees assimilated nitrate as efficiently as ammonium from soils even at low soil nitrate concentration, in contrast to the results from hydroponic experiments showing that ammonium uptake dominated over nitrate. This implies that mature conifers can adapt to increasing availability of nitrate in soil, for example, under the context of globalization of N deposition and global warming.


Asunto(s)
Compuestos de Amonio , Tracheophyta , Bosques , Nitratos/análisis , Nitrógeno/análisis , Suelo , Árboles
14.
Sensors (Basel) ; 20(16)2020 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-32824819

RESUMEN

The individual identification of group-housed pigs plays an important role in breeding process management and individual behavior analysis. Recently, livestock identification methods based on the side view or face image have strict requirements on the position and posture of livestock, which poses a challenge for the application of the monitoring scene of group-housed pigs. To address the issue above, a Weber texture local descriptor (WTLD) is proposed for the identification of group-housed pigs by extracting the local features of back hair, skin texture, spots, and so on. By calculating the differential excitation and multi-directional information of pixels, the local structure features of the main direction are fused to enhance the description ability of features. The experimental results show that the proposed WTLD achieves higher recognition rates with a lower feature dimension. This method can identify pig individuals with different positions and postures in the pig house. Without limitations on pig movement, this method can facilitate the identification of individual pigs with greater convenience and universality.


Asunto(s)
Cara , Sus scrofa , Animales , Monitoreo Fisiológico , Porcinos
15.
Zhongguo Zhong Yao Za Zhi ; 45(6): 1219-1224, 2020 Mar.
Artículo en Chino | MEDLINE | ID: mdl-32281328

RESUMEN

With the rapid outbreak of COVID-19, traditional Chinese medicine(TCM) has been playing an active role against the epidemic. However, the screening of TCM is limited by the development cycle and laboratory conditions, which greatly limits the screening speed. This study established optimization docking models and virtual screening to discovery potential active herbs for the prevention and treatment of the novel coronavirus based on molecular docking technology. The crystal structures of 3 CL protease(Mpro) and papain-like protease(PLP) were obtained from PDB database and homologous modeling respectively, and were used to conduct virtual screening of TCMD 2009 database by CDOCKER program. The ingredients scored in the top 100 were selected respectively, and the candidate herbs were ranked by the numbers of hit molecules. Based on Mpro inhibitors screening, 12 322 potential active components were obtained, and the representative active components included aster pentapeptide A, ligustrazine, salvianolic acid B, etc., and Zingiberis Rhizoma Recens, Asteris Radix et Rhizoma, Notoginseng Radix et Rhizoma, Chuanxiong Rhizoma, Salviae Miltiorrhizae Radix et Rhizoma, Zingiberis Rhizoma, Dianthi Herba, Rhei Radix et Rhizoma, Cistanches Herba were obtained. While 11 294 potential active ingredients were obtained by PLP inhibitor screening, representative active ingredients included gingerketophenol, ginkgol alcohol, ferulic acid, etc., and Codonopsis Radix, Notopterygii Rhizoma et Radix, Zingiberis Rhizoma Recens, Ginkgo Semen, Chuanxiong Rhizoma, Trichosanthis Fructus, Paeoniae Radix Alba, Psoraleae Fructus, Sophorae Flavescentis Radix, Notoginseng Radix et Rhizoma, Angelicae Sinensis Radix were chosen. By combining the diagnosis and treatment scheme of Hunan province's and angiotensin converting enzyme 2(ACE2) inhibitors screening from literature, present study also discussed the rational application of candidate herbs to this epidemic situation. Trichosanthis Fructus obtained by PLP inhibitors screening and Fritillaria verticillata obtained by ACE2 inhibitors screening were parts of the Sangbei Zhisou Powder and Xiaoxianxiong Decoction, which might be applicable to the syndromes of cough and dyspnea. Rhei Radix et Rhizoma screened by Mpro and Trichosanthis Fructus screened by PLP were contained in Maxing Shigan Decoction and Xuanbai Chengqi Decoction, and could be applied to the syndromes of epidemic virus blocking lung. Mori Folium, Lonicerae Japonicae Flos and Forsythiae Fructus obtained by ACE2 inhibitors screening were included in the Sangju Decoction and Yinqiaosan, which might be applicable to the syndromes of warm pathogen attacking lung and cough and dyspnea. The results of this study are intended to provide a reference for the further development of traditional Chinese medicine to deal with the new epidemic.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Betacoronavirus/efectos de los fármacos , Infecciones por Coronavirus/tratamiento farmacológico , Medicamentos Herbarios Chinos/farmacología , Medicina Tradicional China , Neumonía Viral/tratamiento farmacológico , Enzima Convertidora de Angiotensina 2 , COVID-19 , Evaluación Preclínica de Medicamentos , Humanos , Simulación del Acoplamiento Molecular , Pandemias , Peptidil-Dipeptidasa A , SARS-CoV-2 , Tratamiento Farmacológico de COVID-19
16.
Zhongguo Zhong Yao Za Zhi ; 45(6): 1225-1231, 2020 Mar.
Artículo en Chino | MEDLINE | ID: mdl-32281329

RESUMEN

Since the outbreak of 2019-nCoV, the epidemic has developed rapidly and the situation is grim. LANCET figured out that the 2019-nCoV is closely related to "cytokine storm". "Cytokine storm" is an excessive immune response of the body to external stimuli such as viruses and bacteria. As the virus attacking the body, it stimulates the secretion of a large number of inflammatory factors: interleukin(IL), interferon(IFN), C-X-C motif chemokine(CXCL) and so on, which lead to cytokine cascade reaction. With the exudation of inflammatory factors, cytokines increase abnormally in tissues and organs, interfering with the immune system, causing excessive immune response of the body, resulting in diffuse damage of lung cells, pulmonary fibrosis, and multiple organ damage, even death. Arachidonic acid(AA) metabolic pathway is principally used to synthesize inflammatory cytokines, such as monocyte chemotactic protein 1(MCP-1), tumor necrosis factor(TNF), IL, IFN, etc., which is closely related to the occurrence, development and regression of inflammation. Therefore, the inhibition of AA metabolism pathway is benefit for inhibiting the release of inflammatory factors in the body and alleviating the "cytokine storm". Based on the pharmacophore models of the targets on AA metabolic pathway, the traditional Chinese medicine database 2009(TCMD 2009) was screened. The potential herbs were ranked by the number of hit molecules, which were scored by pharmacophore fit value. In the end, we obtained the potential active prescriptions on "cytokine storm" according to the potential herbs in the "National novel coronavirus pneumonia diagnosis and treatment plan(trial version sixth)". The results showed that the hit components with the inhibitory effect on AA were magnolignan Ⅰ, lonicerin and physcion-8-O-ß-D-glucopy-ranoside, which mostly extracted from Magnoliae Officinalis Cortex, Zingiberis Rhizoma Recens, Lonicerae Japonicae Flos, Rhei Radix et Rhizoma, Salviae Miltiorrhizae Radix et Rhizoma, Scutellariae Radix, Gardeniae Fructus, Ginseng Radix et Rhizoma, Arctii Fructus, Dryopteridis Crassirhizomatis Rhizoma, Paeoniaeradix Rubra, Dioscoreae Rhizoma. Finally the anti-2019-nCoV prescriptions were analyzed to obtain the potential active prescriptions on AA metabolic pathway, Huoxiang Zhengqi Capsules, Jinhua Qinggan Granules, Lianhua Qingwen Capsules, Qingfei Paidu Decoction, Xuebijing Injection, Reduning Injection and Tanreqing Injection were found that may prevent 2019-nCoV via regulate cytokines. This study intends to provide reference for clinical use of traditional Chinese medicine to resist new coronavirus.


Asunto(s)
Ácido Araquidónico/metabolismo , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/inmunología , Citocinas/inmunología , Medicamentos Herbarios Chinos/farmacología , Neumonía Viral/tratamiento farmacológico , Neumonía Viral/inmunología , Betacoronavirus , COVID-19 , Humanos , Medicina Tradicional China , Redes y Vías Metabólicas , Pandemias , SARS-CoV-2 , Tratamiento Farmacológico de COVID-19
17.
Environ Sci Technol ; 54(7): 4231-4239, 2020 04 07.
Artículo en Inglés | MEDLINE | ID: mdl-32157884

RESUMEN

Nitrification is a crucial step in ecosystem nitrogen (N) cycling, but scaling up from plot-based measurements of gross nitrification to catchments is difficult. Here, we employed a newly developed method in which the oxygen isotope anomaly (Δ17O) of nitrate (NO3-) is used as a natural tracer to quantify in situ catchment-scale gross nitrification rate (GNR) for a temperate forest from 2014 to 2017 in northeastern China. The annual GNR ranged from 71 to 120 kg N ha-1 yr-1 (average 94 ± 10 kg N ha-1 yr-1) over the 4 years in this forest. This result and high stream NO3- loss (4.2-8.9 kg N ha-1 yr-1) suggest that the forested catchment may have been N-saturated. At the catchment scale, the total N output of 10.7 kg N ha-1 yr-1, via leaching and gaseous losses, accounts for 56% of the N input from bulk precipitation (19.2 kg N ha-1 yr-1). This result indicates that the forested catchment is still retaining a large fraction of N from atmospheric deposition. Our study suggests that estimating in situ catchment-scale GNR over several years when combined with other conventional flux estimates can facilitate the understanding of N biogeochemical cycling and changes in the ecosystem N status.


Asunto(s)
Ecosistema , Ríos , China , Monitoreo del Ambiente , Bosques , Nitratos , Nitrógeno
18.
Drug Dev Ind Pharm ; 46(3): 388-394, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32081054

RESUMEN

To explore the feasibility of preparing traditional Chinese medicine using 3 D printing technology and reduce warpage commonly occurs in large-size tablets, we investigated the prescription, warpage optimization and influence factors of 3 D printing Jiuxiang Jianpi Yangwei (JJY) tablets. The procedures used conformed to the requirements of the 2015 edition of the Chinese Pharmacopeia. The results of the prescription screening showed that 75% ethanol and HPMC (9%) could be adhesives. Meanwhile, stevia (0.5%) and citric acid (0.5%) improved the taste of the 3 D printed JJY tablets. To ensure the quality and appearance of the printed tablets, the best parameters were as follows: drying at room temperature, 40% of the filling density, a 3 mm model height, two outer ring numbers and a printing speed of 15 mm/s. The optimized printed tablets had a smooth appearance, suitable hardness, with the weight uniformity in accordance with the Pharmacopeia. We also prepared personalized JJY cartoon tablets (which contained images of a big-headed pig and a small yellow duck) which were designed to increase the compliance of children when taking their medications. In conclusion, this study reported that 3 D printing technology has great potential for preparing traditional Chinese medicines, and it provided guidance for 3 D printing tablets without warpage.


Asunto(s)
Química Farmacéutica , Medicamentos Herbarios Chinos/administración & dosificación , Impresión Tridimensional , Tecnología Farmacéutica , Estudios de Factibilidad , Dureza , Cumplimiento de la Medicación , Farmacopeas como Asunto , Medicina de Precisión , Comprimidos/normas
19.
Ecol Evol ; 9(13): 7586-7596, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31346424

RESUMEN

Quantifying soil organic carbon (SOC) changes is a fundamental issue in ecology and sustainable agriculture. However, the algorithm-derived biases in comparing SOC status have not been fully addressed. Although the methods based on equivalent soil mass (ESM) and mineral-matter mass (EMMM) reduced biases of the conventional methods based on equivalent soil volume (ESV), they face challenges in ensuring both data comparability and accuracy of SOC estimation due to unequal basis for comparison and using unconserved reference systems. We introduce the basal mineral-matter reference systems (soils at time zero with natural porosity but no organic matter) and develop an approach based on equivalent mineral-matter volume (EMMV). To show the temporal bias, SOC change rates were recalculated with the ESV method and modified methods that referenced to soils at time t1 (ESM, EMMM, and EMMV-t1) or referenced to soils at time zero (EMMV-t0) using two datasets with contrasting SOC status. To show the spatial bias, the ESV- and EMMV-t0-derived SOC stocks were compared using datasets from six sites across biomes. We found that, in the relatively C-rich forests, SOC accumulation rates derived from the modified methods that referenced to t1 soils and from the EMMV-t0 method were 5.7%-13.6% and 20.6% higher than that calculated by the ESV method, respectively. Nevertheless, in the C-poor lands, no significant algorithmic biases of SOC estimation were observed. Finally, both the SOC stock discrepancies (ESV vs. EMMV-t0) and the proportions of this unaccounted SOC were large and site-dependent. These results suggest that although the modified methods that referenced to t1 soils could reduce the biases derived from soil volume changes, they may not properly quantify SOC changes due to using unconserved reference systems. The EMMV-t0 method provides an approach to address the two problems and is potentially useful since it enables SOC comparability and integrating SOC datasets.

20.
Ecol Appl ; 29(6): e01920, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31058370

RESUMEN

The impacts of anthropogenic nitrogen (N) deposition on forest ecosystems depend in large part on its fate. However, our understanding of the fates of different forms of deposited N as well as the redistribution over time within different ecosystems is limited. In this study, we used the 15 N-tracer method to investigate both the short-term (1 week to 3 months) and long-term (1-3 yr) fates of deposited NH4+ or NO3- by following the recovery of the 15 N in different ecosystem compartments in a larch plantation forest and a mixed forest located in northeastern China. The results showed similar total ecosystem retention for deposited NH4+ and NO3- , but their distribution within the ecosystems (plants vs. soil) differed distinctly particularly in the short-term, with higher 15 NO3- recoveries in plants (while lower recoveries in organic layer) than found for 15 NH4+ . The different short-term fate was likely related to the higher mobility of 15 NO3- than 15 NH4+ in soils instead of plant uptake preferences for NO3- over NH4+ . In the long-term, differences between N forms became less prevalent but higher recoveries in trees (particularly in the larch forest) of 15 NO3- than 15 NH4+ tracer persisted, suggesting that incoming NO3- may contribute more to plant biomass increment and forest carbon sequestration than incoming NH4+ . Differences between the two forests in recoveries were largely driven by a higher 15 N recovery in the organic layer (both N forms) and in trees (for 15 NO3- ) in the larch forest compared to the mixed forest. This was due to a more abundant organic layer and possibly higher tree N demand in the larch forest than in the mixed forest. Leachate 15 N loss was minor (<1% of the added 15 N) for both N forms and in both forests. Total 15 N recovery averaged 78% in the short-term and decreased to 55% in the long-term but with increasing amount of 15 N label (re)-redistributed into slow turn-over pools (e.g., trees and mineral soil). The different retention dynamics of deposited NH4+ and NO3- may have implications in environmental policy related to the anthropogenic emissions of the two N forms.


Asunto(s)
Ecosistema , Bosques , China , Nitrógeno , Suelo , Árboles
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