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This study aimed to elucidate the effects of Qingrehuoxue Formula (QRHXF) on NSCLC and its underlying mechanisms. Nude mouse model of subcutaneous tumors was established. QRHXF and erastin were administered orally and intraperitoneally, respectively. Mice's body weight and subcutaneous tumor volumes were measured. The effects of QRHXF on epithelial-mesenchymal transition (EMT), tumor-associated angiogenesis and matrix metalloproteinases (MMPs) were assessed. Importantly, we also analysed the anti-NSCLC of QRHXF form the aspect of ferroptosis and apoptosis and investigate its underlying mechanisms. The safety of QRHXF in mice was also evaluated. QRHXF slowed down the speed of tumor growth and visibly inhibited tumor growth. The expression levels of CD31, VEGFA, MMP2 and MMP9 were prominently suppressed by QRHXF. Furthermore, QRHXF appeared to remarkably inhibite cell proliferation and EMT by decreasing Ki67, N-cadherin and vimentin expression but elevating E-cadherin expression. There were more apoptotic cells in QRHXF group's tumor tissues, and QRHXF treatment increased BAX and cleaved-caspased 3 levels but decreased Bcl-2 levels. QRHXF significantly increased the accumulation of ROS, Fe2+, H2O2, and MDA while reduced GSH levels. SLC7A11 and GPX4 protein levels were considerably suppressed by QRHXF treatment. Moreover, QRHXF triggered ultrastructural changes in the mitochondria of tumor cells. The levels of p53 and p-GSK-3ß were upregulated, whereas that of Nrf2 was downregulated in the groups treated with QRHXF. QRHXF displayed no toxicity in mice. QRHXF activated ferroptosis and apoptosis to suppress NSCLC cell progression via p53 and GSK-3ß/Nrf2 signaling pathways.
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The temporal and spatial characteristics of urban river bacterial communities help us understand the feedback mechanism of bacteria to changes in the aquatic environment. The Fuhe River plays an important role in determining the water ecological environment of Baiyangdian Lake. 16S rRNA gene sequencing was used to study the microbial distribution characteristics in the Fuhe River in different seasons. The results showed that some environmental factors of the surface water (ammonia nitrogen (NH3-N), total nitrogen (TN), and total phosphorus (TP)) were different on the spatial and temporal scales. Moreover, there were no seasonal differences in the contents of TN, TP, total organic carbon (TOC), or heavy metals in the sediments. The distributions of Cyanobacteria, Actinomycetes and Firmicutes in the water and Actinomycetes and Planctomycetes in the sediments differed significantly among seasons (P < 0.05). There were significant spatial differences in bacteria in the surface water, with the highest abundance of Proteobacteria recorded in the river along with the highest nutrient concentration, while the abundance of Bacteroidetes was higher in the upstream than the downstream. Microbial communities in the water were most sensitive to temperature (T) and the TP concentration (P < 0.01). Moreover, differences in the bacterial community were better explained by the content of heavy metals in the sediments than by the chemical characteristics. A PICRUSt metabolic inference analysis showed that the effect of high summer temperatures on the enzyme action led to an increase in the abundances of the metabolic-related genes of the river microorganisms.
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Metais Pesados , Microbiota , Amônia/análise , Bactérias/genética , Carbono/análise , China , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Metais Pesados/análise , Nitrogênio/análise , Fósforo/análise , RNA Ribossômico 16S/genética , Água/análiseRESUMO
Enshi City, in the Hubei Province of China, is known as the world capital of selenium with the most abundant selenium resource. An important selenium hyperaccumulator plant, Cardamine violifolia, was found to naturally grow in this high-selenium ecosystem. However, relatively little is known about the impact of the selenium levels on microbial community and functional shifts in C. violifolia rhizosphere. Here, we tested the hypothesis that underground microbial diversity and function vary along a selenium gradient, including antibiotic resistance genes (ARGs). Comprehensive metagenomic analyses, such as taxonomic investigation, functional detection, and ARG annotation, showed that selenium, mercury, cadmium, lead, arsenic, and available phosphorus and potassium were correlated with microbial diversity and function. Thaumarchaeota was exclusively dominant in the highest selenium concentration of mine outcrop, and Rhodanobacter and Nitrospira were predominant in the high-selenium ecosystem. The plant C. violifolia enriched a high concentration of selenium in the rhizosphere compared to those in the bulk soil, and it recruited Variovorax and Polaromonas in its rhizosphere. Microbial abundance showed a trend of increasing first and then decreasing from low to high selenium concentrations. Annotation of ARGs showed that the multidrug resistance genes adeF, mtrA, and poxtA, the aminoglycoside resistance gene rpsL, and the sulfonamide resistant gene sul2 were enriched in the high-selenium system. It was discovered that putative antibiotic resistant bacteria displayed obvious differences in the farmland and the soils with various selenium concentrations, indicating that a high-selenium ecosystem harbors the specific microbes with a higher capacity to enrich or resist selenium, toxic metals, or antibiotics. Taken together, these results reveal the effects of selenium concentration and the selenium hyperaccumulator plant C. violifolia on shaping the microbial functional community and ARGs. Metalloid selenium-inducible antibiotic resistance is worth paying attention to in future.
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Microbiota , Selênio , Selênio/farmacologia , Selênio/análise , Antibacterianos/farmacologia , Ecossistema , Resistência Microbiana a Medicamentos/genética , Bactérias/genética , Solo , Microbiologia do Solo , Genes BacterianosRESUMO
Objective: Trigeminal neuralgia (TN), one of the most severe and debilitating chronic pain conditions, is often accompanied by mood disorders, such as anxiety and depression. Electroacupuncture (EA) is a characteristic therapy of Traditional Chinese Medicine with analgesic and anxiolytic effects. This study aimed to investigate whether EA ameliorates abnormal TN orofacial pain and anxiety-like behavior by altering synaptic plasticity in the hippocampus CA1. Materials and methods: A mouse infraorbital nerve transection model (pT-ION) of neuropathic pain was established, and EA or sham EA was used to treat ipsilateral acupuncture points (GV20-Baihui and ST7-Xiaguan). Golgi-Cox staining and transmission electron microscopy (TEM) were administrated to observe the changes of synaptic plasticity in the hippocampus CA1. Results: Stable and persistent orofacial allodynia and anxiety-like behaviors induced by pT-ION were related to changes in hippocampal synaptic plasticity. Golgi stainings showed a decrease in the density of dendritic spines, especially mushroom-type dendritic spines, in hippocampal CA1 neurons of pT-ION mice. TEM results showed that the density of synapses, membrane thickness of the postsynaptic density, and length of the synaptic active zone were decreased, whereas the width of the synaptic cleft was increased in pT-ION mice. EA attenuated pT-ION-induced orofacial allodynia and anxiety-like behaviors and effectively reversed the abnormal changes in dendritic spines and synapse of the hippocampal CA1 region. Conclusion: EA modulates synaptic plasticity of hippocampal CA1 neurons, thereby reducing abnormal orofacial pain and anxiety-like behavior. This provides evidence for a TN treatment strategy.
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BACKGROUND: Urbanization and global warming are generating ecological degradation and land pattern alteration problems in natural wetlands. These changes are greatly affecting the ecological services of wetlands. Therefore, there is an urgent need to explore the relationship between pollutants and land-use type for wetland restoration purposes. Zaozhadian Lake is a freshwater wetland in the North China Plain, which is facing degradation and land-use types changes. An experiment for analyzing soil pollutants was conducted in three land-use types of farmland, lake, and ditch in the Zaozhadian Lake. The aims of this study were to identify the distribution, pollution degree, and sources of pollutants in different land-use types, and to explore the influence of land-use type changes on contamination. METHODS: In this study, surface sediments (0-10 cm) of three land types (farmland, lake, and ditch) in Zaozhadian Lake were collected, and heavy metals (Cu, Ni, Zn, Pb, Cd, Cr, Hg), As, total nitrogen (TN), total phosphorus (TP) and organic matter (OM) were determined. Kriging interpolation was used to visualize the pollutants distribution. The pollution degree of TN and TP was evaluated by the Nemerow pollution index. The pollution of heavy metals and As was evaluated by the geological accumulation index (Igeo ) and the potential ecological risk index (RI). Then, dual hierarchical clustering analysis and the principal component analysis were performed to further analyze the impact of land type changes on pollutants. RESULTS: The heavy metal contents in the farmland were higher than other areas, while the TN (3.71 ± 1.03 g kg-1) and OM (57.17 ± 15.16 g kg-1) in lake sediments were higher than that in other regions. Farmland, lake, and ditches had low ecological risks, with RI values of 84.21, 71.34, and 50.78, respectively. The primary heavy metal pollutants are Pb, Cu, and Ni. Furthermore, Cu, As, Ni, Pb, and Zn were primarily derived from agriculture pollution, the source of Cd was the industrial pollution, and Cr mainly originated from natural sources. Nutrients primarily came from the decomposition of aquatic animals, plants, and human-related activities. When the lake area was converted into farmland, the heavy metal concentrations in the soils increased and the TN and OM decreased. Based on the results, this study put forward key strategies including the adjustment of the land-use type and restriction of the entry of pollutants into the wetland ecosystems in the Zaozhadian Lake. More attention should be paid to the impact of land-use type change on pollutants in wetlands.
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Poluentes Ambientais , Metais Pesados , Humanos , Solo , Poluentes Ambientais/análise , Áreas Alagadas , Monitoramento Ambiental/métodos , Ecossistema , Cádmio/análise , Chumbo/análise , Metais Pesados/análise , Fósforo/análise , Medição de RiscoRESUMO
Periodic oxygen supplementation (A-O) strategy was proposed to improve pollutant removal and enhance bioresource production of photosynthetic bacteria (PSB). The A-O strategy obtained higher COD (91.4%) and NH4+-N (78.6%) removal compared with the non-oxygen supplementation (N-O) strategy, which was similar to the continuous oxygen supplementation (C-O) strategy. A-O strategy achieved the highest biomass concentration of 1338.5 mg/L. Bacteriochlorophyll and carotenoids concentration in the A-O strategy were 24.9-31.1% and 15.1-23.7% higher than those in the other two strategies; coenzyme Q10 concentration and content were 52.5% and 21.3% higher than that in the N-O strategy. The metabolomic analysis showed that the A-O strategy enhanced the tricarboxylic acid cycle after fumaric acid formation and ß-alanine metabolism, then caused higher biomass accumulation. The A-O strategy reduced the inhibition of photophosphorylation by oxidative-phosphorylation and maintained both characteristics. Hence, A-O might be an economic strategy for enhancing pollutant removal and bioresource production in PSB-based wastewater treatment.
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Águas Residuárias , Purificação da Água , Biomassa , Bactérias Gram-Negativas , Oxigênio , Oxigenoterapia , FotossínteseAssuntos
Nutrientes , Águas Residuárias , Nitrogênio/análise , Fósforo , Eliminação de Resíduos LíquidosRESUMO
Alzheimer's disease (AD) is a neurodegenerative disease characterized progressive memory loss and cognitive impairment. In previous studies, the activities of extracts of Chinese medicinal herbs to treat brain function disorders caused by AD have already been reported. ZiShen prescription was a traditional Chinese medicine (TCM) compound prescription reformed for AD disease based on the basic theory of TCM. To explore the effect of ZiShen (kidney-reinforcing) prescription on the learning and memory abilities, we made compound AD model rats by injecting d-galactose and ibotenic acid into the abdominal cavity to damage both sides of the nucleus basalis of Meynert with ibotenic acid. The trisected Y-maze was used to test the learning and memory abilities of AD model rats before and after treatment by ZiShen prescription and Piracetam. To investigate the mechanism of ZiShen prescription, the expressions of apoptosis-related genes (Bcl-2/Bax) in the cortex and hippocampus of compound AD model rats were detected in the cortex and hippocampus. The results show that, comparing with Piracetam, a clinical medicine to promote the thinking and memory for AD patients, ZiShen prescription significantly increased the learning and memory abilities of the compound AD model rats. After the treatment of ZiShen prescription, the expression of Bcl-2 was upregulated, along with a downregulation of Bax in the cortex and hippocampus of compound AD model rats. And the results indicated that the clinical benefits of ZiShen prescription were slightly better than Piracetam. Still, further well-designed studies are required to ensure the clinical effect of ZiShen.
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Photosynthetic bacteria (PSB) have two sets of metabolic pathways. They can degrade pollutants through light metabolic under light-anaerobic or oxygen metabolic pathways under dark-aerobic conditions. Both metabolisms function under natural light-microaerobic condition, which demands less energy input. This work investigated the characteristics of PSB wastewater treatment process under that condition. Results showed that PSB had very strong adaptability to chemical oxygen demand (COD) concentration; with F/M of 5.2-248.5 mg-COD/mg-biomass, the biomass increased three times and COD removal reached above 91.5%. PSB had both advantages of oxygen metabolism in COD removal and light metabolism in resource recovery under natural light-microaerobic condition. For pollutants' degradation, COD, total organic carbon, nitrogen, and phosphorus removal reached 96.2%, 91.0%, 70.5%, and 92.7%, respectively. For resource recovery, 74.2% of C in wastewater was transformed into biomass. Especially, coexistence of light and oxygen promote N recovery ratio to 70.9%, higher than with the other two conditions. Further, 93.7% of N-removed was synthesized into biomass. Finally, CO2 emission reduced by 62.6% compared with the traditional process. PSB wastewater treatment under this condition is energy-saving, highly effective, and environment friendly, and can achieve pollution control and resource recovery.
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Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Aerobiose , Análise da Demanda Biológica de Oxigênio , Luz , Fósforo , Fotossíntese , Poluentes Químicos da Água/análiseRESUMO
BACKGROUND: The objective of the study was to investigate the relationship between baseline blood pressure (BP) and the magnitude of BP reduction in patients with essential hypertension treated with nifedipine gastrointestinal therapeutic system (NGTS). METHODS AND PATIENTS: One hundred and thirty-eight patients with essential hypertension were enrolled in this prospective, single-arm, open-label study. NGTS was administered for 24 weeks to achieve target BP of 140/90 mmHg. The dose could be uptitrated to 60 mg/d in case of unsatisfactory BP reduction after 4-week treatment. Home blood pressure measurement was recorded through the initial 1-14 days, and office BP and heart rate were evaluated at 2, 4, 8, 12, and 24 weeks. RESULTS: One hundred and seventeen patients (84.8%) completed the study, and their average BP decreased by 19.0/11.3 mmHg after 24 weeks. The reduction of either systolic or diastolic BP was positively correlated with baseline BP at weeks 2, 4, or 24 after treatment (r=0.603-0.762, all p<0.05). The maximal BP reduction was observed in 83% of patients at 4 weeks of treatment even though the dose of nifedipine remained unchanged (30 mg/day). CONCLUSION: These findings show that BP reduction is greatly influenced by the baseline level. Patients with high baseline BP had maximum reduction after treatment with NGTS, and the maximal antihypertensive efficacy of NGTS could appear even at 4 weeks after treatment initiation.
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Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Nifedipino/farmacologia , Anti-Hipertensivos/administração & dosagem , China , Relação Dose-Resposta a Droga , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipertensão/diagnóstico , Nifedipino/administração & dosagem , Estudos ProspectivosRESUMO
One of the most strikingly universal features of the high-temperature superconductors is that the superconducting phase emerges in the close proximity of the antiferromagnetic phase, and the interplay between these two phases poses a long-standing challenge. It is commonly believed that, as the antiferromagnetic transition temperature is continuously suppressed to zero, there appears a quantum critical point, around which the existence of antiferromagnetic fluctuation is responsible for the development of the superconductivity. In contrast to this scenario, we report the observation of a bi-critical point identified at 2.88GPa and 26.02K in the pressurized high-quality single crystal Ca0.73La0.27FeAs2 by complementary in-situ high pressure measurements. At the critical pressure, we find that the antiferromagnetism suddenly disappears and superconductivity simultaneously emerges at almost the same temperature, and that the external magnetic field suppresses the superconducting transition temperature but hardly affects the antiferromagnetic transition temperature.
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Starch wastewater is a type of nutrient-rich wastewater that contains numerous macromolecular polysaccharides. Using photosynthetic bacteria (PSB) to treat starch wastewater can reduce pollutants and enhance useful biomass production. However, PSB cannot directly degrade macromolecular polysaccharides, which weakens the starch degradation effect. Therefore, co-metabolism with primary substances was employed in PSB wastewater treatment to promote starch degradation. The results indicated that co-metabolism is a highly effective method in synthetic starch degradation by PSB. When malic acid was used as the optimal primary substrate, the chemical oxygen demand, total sugar, macromolecules removal and biomass yield were considerably higher than when primary substances were not used, respectively. Malic acid was the primary substrate that played a highly important role in starch degradation. It promoted the alpha-amylase activity to 46.8â U and the PSB activity, which induced the degradation of macromolecules. The products in the wastewater were ethanol, acetic acid and propionic acid. Ethanol was the primary product throughout the degradation process. The introduction of co-metabolism with malic acid to treat wastewater can accelerate macromolecules degradation and bioresource production and weaken the acidification effect. This method provides another pathway for bioresource recovery from wastewater. This approach is a sustainable and environmentally friendly wastewater treatment technology.
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Rhodobacter sphaeroides/metabolismo , Amido/química , Águas Residuárias/química , Purificação da Água/métodos , Etanol/metabolismo , Malatos/metabolismo , Fotossíntese , alfa-Amilases/metabolismoRESUMO
RATIONALE: Chronic exposure to heroin results in decreased dopamine transporter levels. Jitai tablets, a traditional Chinese medicine, have been effective at increasing striatal dopamine transporter availability after 6 months of treatment. However, it remains unknown how long the heroin-induced impairment persists and whether dopamine transporter can be normalized following long-term abstinence or treatment. OBJECTIVES: This study was to evaluate the time course of dopamine transporter changes in heroin users undergoing long-term abstinence and treatment with Jitai tablets for 1 year. METHODS: Single-photon emission computed tomography using [(99m)Tc]TRODAT-1 was performed on 64 heroin users and 20 healthy subjects to assess striatal dopamine transporter availability at baseline, 3, 6, and 12 months. Heroin users were randomly assigned to treatment with either placebo or Jitai tablets. Depression and anxiety scores were measured before each imaging session. RESULTS: Compared with healthy controls, significant reduction in dopamine transporter availability was found in heroin users at baseline in both the right (by â¼ 31.6%) and left striatum (by â¼ 33.2%). At 6 months, dopamine transporter availability was significantly higher in Jitai tablet-treated group than placebo group in the bilateral striatum (p < 0.01). At 12 months, dopamine transporter levels in both groups were upregulated substantially from baseline but still not recovered to normal levels in the left striatum (p < 0.05). Depression and anxiety scores significantly decreased at 3, 6, and 12 months (p < 0.05). CONCLUSIONS: Our results confirmed that heroin abuse induces pronounced, long-term reduction in dopamine transporter. Treatment with Jitai tablets appears to stimulate recovery.
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Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Medicamentos de Ervas Chinesas/uso terapêutico , Dependência de Heroína/metabolismo , Neostriado/metabolismo , Adulto , Ansiedade/psicologia , Estudos de Casos e Controles , Depressão/psicologia , Método Duplo-Cego , Feminino , Dependência de Heroína/tratamento farmacológico , Dependência de Heroína/psicologia , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , TropanosRESUMO
Large amount of sludge has been a great trouble and raised significant concerns in China. This paper reviewed the current situation of sludge production, management, treatment and disposal in China. Total sludge production in China had an average annual growth of 13% from 2007 to 2013, and 6.25 million tons dry solids was produced in 2013. Per Capita sludge production in China is lower than that in developed countries. However, sludge management is poor in China. Administrative agents of sludge are not in accordance with each other. Laws and regulations of sludge management are incomplete and sometimes unrealistic. As to sludge treatment and disposal, many technical routes have been applied in China. Thickening, conditioning, and dewatering are three most used treatment methods, while application ratios of stabilization and drying are low in China. More than 80% of sludge is disposed by improper dumping in China. Regarding proper disposal, sanitary landfill is the commonest, followed by land application, incineration and building materials. According to the overall situation of China, "thickening-anaerobic digestion-dewatering-land application" is the priority technical route of sludge treatment and disposal. Good changes, current challenges and future perspectives of this technical route in China were analyzed and discussed in details.
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Esgotos , Eliminação de Resíduos Líquidos/métodos , Agricultura , China , Incineração , Esgotos/legislação & jurisprudência , Solo , Eliminação de Resíduos Líquidos/legislação & jurisprudênciaRESUMO
Nitrogen (N) and phosphorus (P) are important limiting nutrients for plant production and consumer performance in a variety of ecosystems. As a result, the N:P stoichiometry of herbivores has received increased attention in ecology. However, the mechanisms by which herbivores maintain N:P stoichiometric homeostasis are poorly understood. Here, using a field manipulation experiment we show that the grasshopper Oedaleus asiaticus maintains strong N:P stoichiometric homeostasis regardless of whether grasshoppers were reared at low or high density. Grasshoppers maintained homeostasis by increasing P excretion when eating plants with higher P contents. However, while grasshoppers also maintained constant body N contents, we found no changes in N excretion in response to changing plant N content over the range measured. These results suggest that O. asiaticus maintains P homeostasis primarily by changing P absorption and excretion rates, but that other mechanisms may be more important for regulating N homeostasis. Our findings improve our understanding of consumer-driven P recycling and may help in understanding the factors affecting plant-herbivore interactions and ecosystem processes in grasslands.
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Fezes/química , Gafanhotos/metabolismo , Homeostase , Nitrogênio/metabolismo , Fósforo/metabolismo , Análise de Variância , Animais , Tamanho Corporal , Feminino , Masculino , Plantas/metabolismoRESUMO
RATIONALE: Previous imaging studies have indicated that the levels of the dopamine transporter (DAT) are reduced in the brains of heroin users. However, whether these changes can be reversed by abstinence and/or treatment remains unclear. OBJECTIVES: This study aims to investigate DAT availability in heroin users and changes in DAT availability after abstinence and treatment with the Jitai tablets, a traditional Chinese medicinal product that is approved for the treatment of opioid addiction. METHODS: Single-photon emission computed tomography (SPECT) with [(99m)Tc] TRODAT-1 was performed on heroin-dependent patients (n = 64) and healthy controls (n = 15). The patients were randomly assigned to treatment with either placebo or the Jitai. All patients underwent SPECT imaging both at baseline and after 6 months of treatment. DAT availability was assessed in the caudate and putamen. Depression and anxiety were evaluated at baseline. RESULTS: DAT availability remained at low levels during a 6-month period in the placebo-treated group but was increased (14-17 %) in the Jitai-treated group. The ratio of DAT availability at month 6 to that at baseline in the Jitai-treated group was significantly higher than that in the placebo-treated group in both the bilateral caudate and putamen. DAT uptake in the striatum was significantly correlated with daily heroin dose, years of heroin use, and depression. CONCLUSIONS: These findings suggest that chronic heroin use induces long-lasting striatal DAT reductions. DAT availability remained unchanged during a 6-month period of abstinence. Treatment with Jitai appears to be effective at increasing striatal DAT availability.
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Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Dependência de Heroína/reabilitação , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Adulto , Ansiedade/epidemiologia , Estudos de Casos e Controles , Núcleo Caudado/metabolismo , Corpo Estriado/metabolismo , Depressão/epidemiologia , Método Duplo-Cego , Medicamentos de Ervas Chinesas/administração & dosagem , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Putamen/metabolismo , ComprimidosRESUMO
Stoichiometric homeostasis, the degree to which an organism maintains its C:N:P ratios around a given species- or stage-specific value despite variation in the relative availabilities of elements in its resource supplies, is a key parameter in ecological stoichiometry. However, its regulation and role in affecting organismal and ecosystem processes is still poorly understood in vascular plants. We performed a sand culture experiment and a field nitrogen (N) and phosphorus (P) addition experiment to evaluate the strength of N, P and N:P homeostasis in higher plants in the Inner Mongolia grassland. Our results showed that homeostatic regulation coefficients (H) of vascular plants ranged from 1.93 to 14.5. H varied according to plant species, aboveground and belowground compartments, plant developmental stage, and overall plant nutrient content and N:P ratio. H for belowground and for foliage were inversely related, while H increased with plant developmental stage. H for N (H(N)) was consistently greater than H for P (H(P)) while H for N:P (H(N:P)) was consistently greater than H(N) and H(P). Furthermore, species with greater N and P contents and lower N:P were less homeostatic, suggesting that more homeostatic plants are more conservative nutrient users. The results demonstrate that H of plants encompasses a considerable range but is stronger than that of algae and fungi and weaker than that of animals. This is the first comprehensive evaluation of factors influencing stoichiometric homeostasis in vascular plants.
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Chenopodium/metabolismo , Homeostase , Nitrogênio/metabolismo , Fósforo/metabolismo , Poaceae/metabolismo , Chenopodium/crescimento & desenvolvimento , Mongólia , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Poaceae/crescimento & desenvolvimento , Solo/químicaRESUMO
Understanding how food web interactions alter the processing of limiting nutrient elements is an important goal of ecosystem ecology. An experiment manipulating densities of the grasshopper Oedaleus asiaticus was performed to assess top-down effects of grasshoppers on C:N:P stoichiometry of plants and soil in a grassland ecosystem in Inner Mongolia (China). With increased grasshopper feeding, plant biomass declined fourfold, litter abundance increased 30%, and the plant community became dominated by non-host plant taxa. Plant stoichiometric response depended on whether or not the plant was a grasshopper host food species: C:N and C:P ratios increased with increasing grasshopper density (GD) for host plants but decreased in non-host plants. These data suggest either a direct transfer of grasshopper-recycled nutrients from host to non-host plants or a release of non-host plants from nutrient competition with heavily grazed host plants. Litterfall C:N and C:P decreased across moderate levels of grasshopper density but no effects on C:N:P stoichiometry in the surface soil were observed, possibly due to the short experimental period. Our observations of divergent C:N:P stoichiometric response among plant species highlight the important role of grasshopper herbivory in regulating plant community structure and nutrient cycling in grassland ecosystems.
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Ecossistema , Gafanhotos , Plantas/química , Solo/química , Animais , Carbono/análise , Ciclo do Carbono , Feminino , Masculino , Mongólia , Nitrogênio/análise , Ciclo do Nitrogênio , Fósforo/análiseRESUMO
Previous study showed that sonication was effective to reduce waste activated sludge (WAS) using artificial wastewater. This paper confirms the viability and evaluates the performance of this method in practical wastewater treatment using urban sewage without temperature control. The results showed that sonication significantly lowered the WAS and biomass synthesis, and greatly enhanced the mineralization of sewage organics. The optimal specific energy for sludge lysis was 20.0k Wh/kg DS. Further energy-increase had little benefit on WAS reduction. When the specific energy was 20.0kWh/kgDS and the sludge recycle ratio was 0.007, the WAS decreased by 54%, the biomass synthesis abated by 59%, and the sewage mineralization ratio increased from 31% to 58%. The effluent COD and nitrogen were stable but phosphorus was higher than that of the control bioreactor. The COD removal was lower but the WAS reduction was higher for urban sewage than for artificial wastewater. The accumulation pattern of heavy metals in sludge was greatly alternated by the sonication-cryptic growth; and different metals behaved differently. The sludge Ni concentration increased by 141% while As decreased by 53%.
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Esgotos , Ultrassom , Eliminação de Resíduos Líquidos/métodos , Biomassa , Carbono , Metais Pesados/análise , Nitrogênio , FósforoRESUMO
The population distribution patterns of fig wasps associated with Ficus racemosa in Xishuangbanna were studied by using several indexes. The results indicated that the distribution patterns of 6 fig wasp species were all clump. The aggregative intensity of pollinating wasp (Ceratosolen fusciceps) population at primeval rain forest was nearly equal to that at seriously disturbed site, whereas they were both much higher than that at moderately disturbed site. In the meanwhile, the population aggregative intensity for the same wasp species was higher in rainy season than in dry-hot season, and the lowest was occurred in foggy-cool season. Non-pollinating wasp (Platyneura testacea, Platyneura mayri, Platyneura agraensis, Apocrypta westwoodi, Apocrypta sp.) population and each of their sex group were varied significantly in aggregative intensity, responding to the habitat change and seasonal alteration. The protection of original habitat should be focused on the protection of the mutualism of Ficus racemosa and fig wasps.