Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Neurochem Res ; 48(5): 1361-1369, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36454394

RESUMO

BACKGROUND: Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), regulated by AMPK, is an important regulator of mitochondrial fusion. At present, whether the AMPK/PGC-1α signaling pathway regulates mitochondrial dynamics in epileptic rats is still unknown. METHODS: Adult male Sprague-Dawley (SD) rats were randomly divided into fourgroups: the control group (0.9% saline, n = 5), the EP groups (lithium-pilocarpine was used to induce epilepsy, and tissues were harvested at 6 and 24 h, every time point, n = 5), the EP + Compound C group (the specific inhibitor of PGC-1α, 15 mg/kg in 2% DMSO, n = 5), and the EP + DMSO group (0.9% saline + 2% DMSO, n = 5). To investigate whether PGC-1α participates in seizures by regulating the expression of mitofusin1/2(MFN1/2)in rats. RESULTS: In this study, the behavioral results indicate that the seizure susceptibility of the rats to epilepsy was increased when the expression of PGC-1α was inhibited. Subsequently, Western blot results suggested that the expression level of both MFN1 and MFN2 in the hippocampus was higher at 6 and 24 h after an epileptic seizure. Besides, the expression of PGC-1α and MFN2 was significantly decreased in the hippocampus when the epileptic rats were treated with Compound C. Furthermore, the immunofluorescence analysis of the localization of MFN1/2 and PGC-1α showed that MFN1/2 was mainly expressed in neurons but not astrocytes in the hippocampus and cerebral cortex of rats. Meanwhile, PGC-1α colocalized with the excitatory post-synaptic marker PSD95, suggesting that PGC-1α may regulate the seizure susceptibility of the rats by mediating excitatory post-synaptic signaling. CONCLUSION: The AMPK/PGC-1α signaling pathway may play an important role in the lithium-pilocarpine-induced epileptic rat model by mediating the expression of fusion proteins.


Assuntos
Epilepsia , Dinâmica Mitocondrial , Ratos , Masculino , Animais , Ratos Sprague-Dawley , Proteínas Quinases Ativadas por AMP/metabolismo , Dimetil Sulfóxido , Lítio , Pilocarpina , Solução Salina , Convulsões/induzido quimicamente , Epilepsia/induzido quimicamente , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo
2.
Environ Res ; 227: 115829, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37011802

RESUMO

Wetland sediment is an important nitrogen pool and a source of the greenhouse gas nitrous oxide (N2O). Modification of coastal wetland landscape due to plant invasion and aquaculture activities may drastically change this N pool and the related dynamics of N2O. This study measured the sediment properties, N2O production and relevant functional gene abundances in 21 coastal wetlands across five provinces along the tropical-subtropical gradient in China, which all had experienced the same sequence of habitat transformation from native mudflats (MFs) to invasive Spartina alterniflora marshes (SAs) and subsequently to aquaculture ponds (APs). Our results showed that change from MFs to SAs increased the availability of NH4+-N and NO3--N and the abundance of functional genes related to N2O production (amoA, nirK, nosZ Ⅰ, and nosZ Ⅱ), whereas conversion of SAs to APs resulted in the opposite changes. Invasion of MFs by S. alterniflora increased N2O production potential by 127.9%, whereas converting SAs to APs decreased it by 30.4%. Based on structural equation modelling, nitrogen substrate availability and abundance of ammonia oxidizers were the key factors driving the change in sediment N2O production potential in these wetlands. This study revealed the main effect patterns of habitat modification on sediment biogeochemistry and N2O production across a broad geographical and climate gradient. These findings will help large-scale mapping and assessing landscape change effects on sediment properties and greenhouse gas emissions along the coast.


Assuntos
Gases de Efeito Estufa , Nitrogênio , Nitrogênio/análise , Óxido Nitroso , Amônia , Ecossistema , Áreas Alagadas , Solo/química
3.
J Environ Manage ; 338: 117813, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-36996562

RESUMO

The extensive conversion of carbon-rich coastal wetland to aquaculture ponds in the Asian Pacific region has caused significant changes to the sediment properties and carbon cycling. Using field sampling and incubation experiments, the sediment anaerobic CO2 production and CO2 emission flux were compared between a brackish marsh and the nearby constructed aquaculture ponds in the Min River Estuary in southeastern China over a three-year period. Marsh sediment had a higher total carbon and lower C:N ratio than aquaculture pond sediment, suggesting the importance of marsh vegetation in supplying labile organic carbon to the sediment. Conversion to aquaculture ponds significantly decreased sediment anaerobic CO2 production rates by 69.2% compared to the brackish marsh, but increased CO2 emission, turning the CO2 sink (-490.8 ± 42.0 mg m-2 h-1 in brackish marsh) into a source (6.2 ± 3.9 mg m-2 h-1 in aquaculture pond). Clipping the marsh vegetation resulted in the highest CO2 emission flux (382.6 ± 46.7 mg m-2 h-1), highlighting the critical role of marsh vegetation in capturing and sequestering carbon. Sediment anaerobic CO2 production and CO2 uptake (in brackish marsh) and emission (in aquaculture ponds) were highest in the summer, followed by autumn, spring and winter. Redundancy analysis and structural equation modeling showed that the changes of sediment temperature, salinity and total carbon content accounted for more than 50% of the variance in CO2 production and emission. Overall, the results indicate that vegetation clearing was the main cause of change in CO2 production and emission in the land conversion, and marsh replantation should be a primary strategy to mitigate the climate impact of the aquaculture sector.


Assuntos
Estuários , Áreas Alagadas , Monitoramento Ambiental , Lagoas , Dióxido de Carbono/análise , Anaerobiose , Aquicultura/métodos , China , Carbono/análise
4.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 39(10): 1158-1160, 2022 Oct 10.
Artigo em Zh | MEDLINE | ID: mdl-36184104

RESUMO

OBJECTIVE: To analyze the molecular characteristics of a ABO subgroup. METHODS: The ABO phenotype was determined with the tube method. Exons of the ABO gene were analyzed by Sanger sequencing, and haplotypes of exons 6 and 7 were analyzed by cloning sequencing. RESULTS: By forward typing, the red blood cells showed 3+ agglutination reaction with anti-A and 4+ agglutination with anti-B. A weak reaction with A1 cells and no agglutination reaction with B, O cells by the reverse typing. Sequencing results showed heterozygosity including c.297A>G, c.467C>T, c.526C>G, c.608A>G, c.657C>T, c.703G>A, c.796C>A, c.803G>C, c.930G>A. Cloning sequencing revealed a c.608A>G variant in the A allele compared with the ABO*A1.02. CONCLUSION: A new variant site of subtype A of c.608G variation has been identified.


Assuntos
Sistema ABO de Grupos Sanguíneos , Sistema ABO de Grupos Sanguíneos/genética , Alelos , Éxons , Genótipo , Heterozigoto , Fenótipo
6.
J Nematol ; 47(1): 71-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25861119

RESUMO

Root-knot nematodes (Meloidogyne spp.) are a significant problem in potato (Solanum tuberosum) production. There is no potato cultivar with Meloidogyne resistance, even though resistance genes have been identified in wild potato species and were introgressed into breeding lines. The objectives of this study were to generate stable transgenic potato lines in a cv. Russet Burbank background that carry an RNA interference (RNAi) transgene capable of silencing the 16D10 Meloidogyne effector gene, and test for resistance against some of the most important root-knot nematode species affecting potato, i.e., M. arenaria, M. chitwoodi, M. hapla, M. incognita, and M. javanica. At 35 days after inoculation (DAI), the number of egg masses per plant was significantly reduced by 65% to 97% (P < 0.05) in the RNAi line compared to wild type and empty vector controls. The largest reduction was observed in M. hapla, whereas the smallest reduction occurred in M. javanica. Likewise, the number of eggs per plant was significantly reduced by 66% to 87% in M. arenaria and M. hapla, respectively, compared to wild type and empty vector controls (P < 0.05). Plant-mediated RNAi silencing of the 16D10 effector gene resulted in significant resistance against all of the root-knot nematode species tested, whereas R Mc1(blb) , the only known Meloidogyne resistance gene in potato, did not have a broad resistance effect. Silencing of 16D10 did not interfere with the attraction of M. incognita second-stage juveniles to roots, nor did it reduce root invasion.

7.
Water Res ; 249: 120943, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38064785

RESUMO

Aquaculture ponds are potential hotspots for carbon cycling and emission of greenhouse gases (GHGs) like CO2 and CH4, but they are often poorly assessed in the global GHG budget. This study determined the temporal variations of CO2 and CH4 concentrations and diffusive fluxes and their environmental drivers in coastal aquaculture ponds in southeastern China over a five-year period (2017-2021). The findings indicated that CH4 flux from aquaculture ponds fluctuated markedly year-to-year, and CO2 flux varied between positive and negative between years. The coefficient of inter-annual variation of CO2 and CH4 diffusive fluxes was 168% and 127%, respectively, highlighting the importance of long-term observations to improve GHG assessment from aquaculture ponds. In addition to chlorophyll-a and dissolved oxygen as the common environmental drivers, CO2 was further regulated by total dissolved phosphorus and CH4 by dissolved organic carbon. Feed conversion ratio correlated positively with both CO2 and CH4 concentrations and fluxes, showing that unconsumed feeds fueled microbial GHG production. A linear regression based on binned (averaged) monthly CO2 diffusive flux data, calculated from CO2 concentrations, can be used to estimate CH4 diffusive flux with a fair degree of confidence (r2 = 0.66; p < 0.001). This algorithm provides a simple and practical way to assess the total carbon diffusive flux from aquaculture ponds. Overall, this study provides new insights into mitigating the carbon footprint of aquaculture production and assessing the impact of aquaculture ponds on the regional and global scales.


Assuntos
Dióxido de Carbono , Lagoas , Carbono , Mudança Climática , Metano/análise , Monitoramento Ambiental , Aquicultura , China , Óxido Nitroso/análise
8.
Mol Med Rep ; 27(2)2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36633134

RESUMO

In recent decades, studies have reported that inflammation serves key roles in epilepsy and that high mobility group box protein­1 (HMGB1) may be involved in status epilepticus. However, it has not been reported whether HMGB1 participates in the pathogenesis of status epilepticus through the regulation of the p38 mitogen­activated protein kinase (p38MAPK) signalling pathway. In the present study, Sprague­Dawley rats were randomly divided into four groups as follows: Control, status epilepticus (SE), dimethyl sulfoxide treatment (DMSO + SE), and glycyrrhizin treatment (GL + SE) groups. Behavioural changes were then evaluated using the Racine score. In the hippocampus, the protein expression levels of HMGB1 were assessed using western blotting, the neuronal damage was evaluated using haematoxylin and eosin staining and transmission electron microscopy, and the activation of microglia was assessed using immunochemistry and immunofluorescence. The results demonstrated that, in the hippocampal region, HMGB1 existed in neurons and astrocytes and the protein expression levels of HMGB1, p38MAPK and phosphorylated­p38MAPK were significantly inhibited after treatment with GL. Furthermore, GL could alleviate neuronal injury in the CA1 region of the hippocampus and prevented HMGB1 translocation from the nucleus into the cytoplasm in these areas. These findings expand the understanding of how HMGB1 may participate in SE and lay a foundation for evaluation of HMGB1 as a drug target.


Assuntos
Ácido Glicirrízico , Proteína HMGB1 , Estado Epiléptico , Proteínas Quinases p38 Ativadas por Mitógeno , Animais , Ratos , Ácido Glicirrízico/farmacologia , Ácido Glicirrízico/uso terapêutico , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Proteína HMGB1/metabolismo , Ratos Sprague-Dawley , Estado Epiléptico/tratamento farmacológico , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Transdução de Sinais/efeitos dos fármacos
9.
Sci Total Environ ; 897: 165442, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37442465

RESUMO

In this study, the effect of cold isostatic pressure (CIP) pretreatment on the physicochemical properties and subsequent anaerobic digestion (AD) performance of corn straw (CS) was explored. The CS was subjected to CIP pretreatment by pressures of 200, 400 and 600 MPa, respectively, while AD was carried out at medium temperature (35 ± 2 °C). The results showed that CIP pretreatment disrupted the dense structure of the CS and altered the crystallinity index and surface hydrophobicity of the CS, thereby affecting the AD process. The presence of CIP pretreatment increased the initial reducing sugar concentration by 0.11-0.27 g/L and increased the maximum volatile fatty acids content by 112.82-436.64 mg/L, which facilitated the process of acidification and hydrolysis of the AD. It was also observed that the CIP pretreatment maintained the pH in the range of 6.37-7.30, maintaining the stability of the overall system. Moreover, the cumulative methane production in the CIP pretreatment group increased by 27.17 %-64.90 % compared to the control group. Analysis of the microbial results showed that CIP pretreatment increased the abundance of cellulose degrading bacteria Ruminofilibacter from 21.50 % to 27.53 % and acetoclastic methanogen Methanosaeta from 45.48 % to 56.92 %, thus facilitating the hydrolysis and methanogenic stages. The energy conversion analysis showed that CIP is a green and non-polluting pretreatment strategy for the efficient AD of CS to methane.


Assuntos
Celulose , Zea mays , Anaerobiose , Zea mays/química , Bactérias , Metano , Reatores Biológicos , Biocombustíveis
10.
Clin Chim Acta ; 548: 117455, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37394163

RESUMO

Staphylococcus epidermidis is an opportunistic pathogenic microorganism that is an important cause of cross-infection in hospitals. The development of rapid and effective detection techniques is important for its control. The application of traditional identification and PCR-based methods is limited by their requirements for both laboratory instrumentation and trained personnel. To overcome this issue, we developed a fast detection approach for S. epidermidis that was based on recombinase polymerase amplification (RPA) and lateral flow strips (LFS). First, five pairs of primers were designed for molecular diagnosis using the sesB gene as the target, and were screened for their amplification performance and the formation of primer dimers. Specific probes were then designed based on the best primer pairs screened, which were susceptible to primer-dependent artifacts and generated false-positive signals when used for LFS detection. This weakness of the LFS assay was overcome by modifying the sequences of the primers and probes. The efficacy of these measures was rigorously tested, and improved the RPA-LFS system. Standardized systems completed the amplification process within 25 min at a constant temperature of 37 °C, followed by visualization of the LFS within 3 min. The approach was very sensitive (with a detection limit of 8.91 CFU/µL), with very good interspecies specificity. In the analysis of clinical samples, the approach produced results consistent with PCR and 97.78% consistent with the culture-biochemical method, with a kappa index of 0.938. Our method was rapid, accurate, and less dependent on equipment and trained personnel than traditional methods, and provided information for the timely development of rational antimicrobial treatment plans. It has high potential utility in clinical settings, particularly in resource-constrained locations.


Assuntos
Recombinases , Staphylococcus epidermidis , Humanos , Recombinases/genética , Staphylococcus epidermidis/genética , Sensibilidade e Especificidade , Técnicas de Amplificação de Ácido Nucleico/métodos , Reação em Cadeia da Polimerase/métodos , Nucleotidiltransferases
11.
Front Cell Dev Biol ; 11: 1167626, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37621773

RESUMO

Research investigating the correlation between human trace element levels and disease alterations is growing. Epilepsy, a common nervous system disease, has also been found to be closely related to abnormal levels of trace elements. Studies continue to explore mechanisms of various trace elements involved in epileptic seizures through experimental animal models of epilepsy. Thus, we reviewed the research progress on the correlation between trace element levels and epilepsy in recent years and found that the trace elements most closely related to epilepsy are mainly metal ions such as selenium, iron, copper, zinc, and manganese. These results indicate that the changes in some trace elements are closely related to the increase in epilepsy susceptibility. In addition, after treatment with drugs and a ketogenic diet, the concentration of trace elements in the serum of patients with epilepsy changes. In other words, the abnormality of trace element concentrations is of great significance in the occurrence and development of epilepsy. This article is a literature update on the potential role of trace element imbalance in the development of epilepsy, providing new references for the subsequent prevention and treatment of epilepsy.

12.
Front Immunol ; 14: 1118236, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36742325

RESUMO

Herpes simplex virus (HSV) is the most common pathogen of infectious encephalitis, accounting for nearly half of the confirmed cases of encephalitis. Its clinical symptoms are often atypical. HSV PCR in cerebrospinal fluid is helpful for diagnosis, and the prognosis is usually satisfactory after regular antiviral treatment. Interestingly, some patients with recurrent encephalitis have little antiviral effect. HSV PCR in cerebrospinal fluid is negative, but glucocorticoid has a significant effect after treatment. Specific antibodies, such as the NMDA receptor antibody, the GABA receptor antibody, and even some unknown antibodies, can be isolated from cerebrospinal fluid, proving that the immune system contributes to recurrent encephalitis, but the specific mechanism is still unclear. Based on recent studies, we attempt to summarize the relationship between herpes simplex encephalitis and innate immunity, providing more clues for researchers to explore this field further.


Assuntos
Encefalite por Herpes Simples , Imunidade Inata , Humanos , Anticorpos/uso terapêutico , Encefalite por Herpes Simples/tratamento farmacológico , Encefalite por Herpes Simples/diagnóstico , Prognóstico , Simplexvirus
13.
Front Neurosci ; 16: 870197, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35720723

RESUMO

Epilepsy is a common chronic brain disease. There are many clinical methods to control epileptic seizures, such as anti-seizure medications (ASMs) or surgical removal of epileptogenic lesions. However, the pathophysiology of epilepsy is still unknown, making it difficult to control or prevent it. The host's immune system monitors gut microbes, interacts with microbes through pattern recognition receptors such as Toll-like receptors (TLRs) and NOD-like receptors (NLRs) expressed by innate immune cells, and activates immune responses in the body to kill pathogens and balance the relationship between microbes and host. In addition, inflammatory responses induced by the innate immune system are seen in animal models of epilepsy and temporal lobe epilepsy brain tissue to combat pathogens or injuries. This review summarizes the potential relationship between gut microbes, innate immunity, and epilepsy based on recent research to provide more hints for researchers to explore this field further.

14.
Medicine (Baltimore) ; 101(43): e31378, 2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36316849

RESUMO

RATIONALE: Hereditary motor-sensory peripheral neuropathy, or Charot-Marie-Tooth (CMT) Charcot-Marie-Tooth disease is an inherited peripheral neuropathy characterized by progressive limb weakness and muscle atrophy. As the disease progresses, sensory and autonomic involvement may occur. We report a case of CMT associated with SOD1 gene mutation, in order to provide new ideas for clinical disease diagnosis. PATIENT CONCERNS: A 50-years-old female patient was admitted to the hospital with "progressive weakness of the right lower extremity for 5 years, aggravating, and weakness of the left lower extremity for 4 months". DIAGNOSIS: The patient was diagnosed CMT. INTERVENTION: Nerve nutrition and rehabilitation therapy were given, but the patient's condition still did not improve significantly. OUTCOMES: The improvement of symptoms was not obvious. LESSONS: The clinical manifestations and electromyography results of this patient are consistent with the characteristics of CMT. The peripheral nerve-related hereditary gene test found mutation in SOD1. It is possible that this mutation is linked to CMT. The disease is a neurodegenerative disease, that may be slowed by physical therapy and rehabilitation, but could not be healed.


Assuntos
Doença de Charcot-Marie-Tooth , Neuropatias Hereditárias Sensoriais e Autônomas , Neuropatia Hereditária Motora e Sensorial , Doenças Neurodegenerativas , Feminino , Humanos , Pessoa de Meia-Idade , Doença de Charcot-Marie-Tooth/diagnóstico , Doença de Charcot-Marie-Tooth/genética , Superóxido Dismutase-1/genética , Neuropatia Hereditária Motora e Sensorial/diagnóstico , Neuropatia Hereditária Motora e Sensorial/genética , Mutação
15.
Ibrain ; 8(2): 241-245, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37786894

RESUMO

The aim of this article was to analyze the clinical and genetic characteristics of a patient with Huntington's disease and her family. We analyzed the clinical data of a patient with Huntington's disease and her family members in the Department of Neurology of our hospital, drew the genetic pedigree, and used gene fragment analysis to detect and analyze the genes of three people in the family according to the principle of informed consent. The genetic pedigree of the family was consistent with that of autosomal dominant diseases. A total of five people in this family developed the disease, two died, and the main clinical manifestations were dystonia, ataxia, and cognitive impairment. Three people in this family underwent genetic testing, and two exhibited normal genotypes. The cytosine-adenine-guanine trinucleotide (CAG) repeats of the proband were abnormally amplified, and the number of repeats reached 43. The main clinical features of the patient included chronic obscure onset, obvious positive family genetic history, clinical features of involuntary limb movement with cognitive impairment, rapid disease progression, poor treatment effect, and abnormal amplification of CAG repeats as shown through genetic testing. All the above features met the diagnostic criteria of Huntington's disease.

16.
Environ Pollut ; 305: 119276, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35405221

RESUMO

Widespread conversion of coastal wetlands into aquaculture ponds in coastal region often results in degradation of the wetland ecosystems, but its effects on sediment's potential to produce greenhouse gases remain unclear. Using field sampling, incubation experiments and molecular analysis, we studied the sediment CH4 production potential and the relevant microbial communities in a brackish marsh and the nearby aquaculture ponds in the Min River Estuary in southeastern China. Sediment CH4 production potential was higher in the summer and autumn months than in spring and winter months, and it was significantly correlated with sediment carbon content among all environmental variables. The mean sediment CH4 production potential in the aquaculture ponds (20.1 ng g-1 d-1) was significantly lower than that in the marsh (45.2 ng g-1 d-1). While Methanobacterium dominated in both habitats (41-59%), the overall composition of sediment methanogenic archaea communities differed significantly between the two habitats (p < 0.05) and methanogenic archaea alpha diversity was lower in the aquaculture ponds (p < 0.01). Network analysis revealed that interactions between sediment methanogenic archaea were much weaker in the ponds than in the marsh. Overall, these findings suggest that conversion of marsh land to aquaculture ponds significantly altered the sediment methanogenic archaea community structure and diversity and lowered the sediment's capacity to produce CH4.


Assuntos
Lagoas , Áreas Alagadas , Aquicultura , Archaea , Ecossistema , Metano
17.
Environ Pollut ; 294: 118568, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34838712

RESUMO

While Asia is projected to be one of the major nitrous oxide (N2O) sources in the coming decades, a more accurate assessment of N2O budget has been hampered by low data resolution and poorly constrained emission factor (EF). Since urbanized coastal reservoirs receive high nitrogen loads from diverse sources across a heterogeneous landscape, the use of a single fixed EF may lead to large errors in N2O assessment. In this study, we conducted high spatial resolution sampling of dissolved N2O, nitrate-nitrogen (NO3--N) and other physico-chemical properties of surface water in Wenwusha Reservoir and other types of water bodies (river, drainage channels, and aquaculture ponds) in its catchment areas in southeastern China between November 2018 and June 2019. The empirically derived EF (calculated as N2O-N:NO3--N) for the reservoir showed considerable spatial variations, with a 10-fold difference ranging from 0.8 × 10-3 to 8.8 × 10-3. The average EF varied significantly among the four types of water bodies in the following descending order: aquaculture ponds > river > drainage channels > reservoir. Across all the water bodies, the mean EF in summer was 1.8-3.5 and 1.7-2.8 fold higher than that in autumn and spring, respectively, owing to the elevated water temperature. Overall, our derived EF deviated considerably from the IPCC default value, which implied that the use of default EF could result in over- or under-estimation of N2O emissions by up to 42%. We developed a multiple regression model that could explain 82% of the variance in EF based on water temperature and the ratio between dissolved organic carbon and nitrate-nitrogen (p < 0.001), which could be used to improve the estimate of EF for assessing N2O emission from coastal reservoirs and other similar environments.


Assuntos
Monitoramento Ambiental , Óxido Nitroso , China , Matéria Orgânica Dissolvida , Nitrogênio/análise , Óxido Nitroso/análise , Rios
18.
Water Res ; 227: 119326, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36368085

RESUMO

Land reclamation is a major threat to the world's coastal wetlands, and it may influence the biogeochemical cycling of nitrogen in coastal regions. Conversion of coastal marshes into aquaculture ponds is common in the Asian Pacific region, but its impacts on the production and emission of nitrogen greenhouse gases remain poorly understood. In this study, we compared N2O emission from a brackish marsh and converted shrimp aquaculture ponds in the Shanyutan wetland, the Min River Estuary in Southeast China over a three-year period. We also measured sediment and porewater properties, relevant functional gene abundance, sediment N2O production potential and denitrification potential in the two habitats. Results indicated that the pond sediment had lower N-substrate availability, lower ammonia oxidation (AOA and comammox Nitrospira amoA), nitrite reduction (nirK and nirS) and nitrous oxide reduction (nosZ Ⅰ and nosZ Ⅱ) gene abundance and lower N2O production and denitrification potentials than in marsh sediments. Consequently, N2O emission fluxes from the aquaculture ponds (range 5.4-251.8 µg m-2 h-1) were significantly lower than those from the marsh (12.6-570.7 µg m-2 h-1). Overall, our results show that conversion from marsh to shrimp aquaculture ponds in the Shanyutan wetland may have diminished nutrient input from the catchment, impacted the N-cycling microbial community and lowered N2O production capacity of the sediment, leading to lower N2O emissions. Better post-harvesting management of pond water and sediment may further mitigate N2O emissions caused by the aquaculture operation.


Assuntos
Lagoas , Áreas Alagadas , Monitoramento Ambiental , Aquicultura/métodos , Óxido Nitroso/análise , Nitrogênio/análise , Desnitrificação
19.
Environ Res ; 111(7): 909-16, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21704985

RESUMO

We compared the influence of invasion by an alien invasive species (Spartina alterniflora, smooth cordgrass) and a native aggressive species (Phragmites australis, common reed) as they have expanded into the native Cyperus malaccensis (shichito matgrass)-dominated wetland ecosystem in the Min River estuary of southeast China. S. alterniflora is a perennial grass native to North America, which has spread rapidly along the southeast coast of China since its introduction in 1979. Our study compared the above and belowground biomass, net primary production, litter decomposition, plant nutrient stocks and soil organic carbon storage of the grasses in three ecosystems: (1) the native ecosystem dominated by C. malaccensis; (2) ecosystems previously dominated by C. malaccensis but presently replaced by P. australis; and (3) ecosystems previously dominated by C. malaccensis but presently replaced by S. alterniflora. Our results demonstrate that the recent invasion (3 years) of the exotic invasive species S. alterniflora has already significantly increased live aboveground biomass and aboveground plant nutrient stocks. However, there was no significant difference in these variables between native aggressive species P. australis and native C. malaccensis. The majority of belowground root Carbon (C), Nitrogen (N) and phosphorus (P) stocks of the three plant species were all distributed in the upper surface layer and there was a decrease with soil depth. There was little difference in litter decomposition rates among the three grass species; they were ranked in the following order: C. malaccensis>S. alterniflora>P. australis. Litter element concentration showed similar patterns for the three species. However, important differences were found between N and P; the litter N concentrations in each of the three species were greater at the end of the 280 days decomposition than at the start, but P concentrations followed a fluctuating pattern during the decomposition period. Soil organic carbon stocks (0-50cm) under S. alterniflora, P. australis and C. malaccensis stands were statistically indistinguishable, which may be due to the invasion of S. alterniflora having been a relatively recent phenomenon. Thus, recent invasion of the exotic species S. alterniflora has already altered the nutrient cycle of C. malaccensis in the ecosystem in the Min River estuary.


Assuntos
Ecossistema , Espécies Introduzidas , Poaceae/metabolismo , Áreas Alagadas , Biomassa , Carbono/metabolismo , China , Nitrogênio/metabolismo , Fósforo/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Solo/química
20.
Front Endocrinol (Lausanne) ; 12: 787854, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34992582

RESUMO

Epilepsy is a common chronic neurological disease that manifests as recurrent seizures. The incidence and prevalence of epilepsy in women are slightly lower than those in men. Polycystic ovary syndrome (PCOS), a reproductive endocrine system disease, is a complication that women with epilepsy are susceptible to, and its total prevalence is 8%-13% in the female population and sometimes as high as 26% in female epilepsy patients. The rate of PCOS increased markedly in female patients who chose valproate (VPA), to 1.95 times higher than that of other drugs. In addition, patients receiving other anti-seizure medications (ASMs), such as lamotrigine (LTG), oxcarbazepine (OXC), and carbamazepine (CBZ), also have reproductive endocrine abnormalities. Some scholars believe that the increase in incidence is related not only to epilepsy itself but also to ASMs. Epileptiform discharges can affect the activity of the pulse generator and then interfere with the reproductive endocrine system by breaking the balance of the hypothalamic-pituitary-ovarian (HPO) axis. ASMs may also cause PCOS-like disorders of the reproductive endocrine system through the HPO axis. Moreover, other factors such as hormone metabolism and related signalling pathways also play a role in it.


Assuntos
Anticonvulsivantes/efeitos adversos , Epilepsia/tratamento farmacológico , Epilepsia/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Síndrome do Ovário Policístico/metabolismo , Epilepsia/epidemiologia , Feminino , Humanos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Síndrome do Ovário Policístico/induzido quimicamente , Síndrome do Ovário Policístico/epidemiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA