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1.
Opt Express ; 32(11): 18441-18452, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38858999

RESUMO

Imaging the complex dynamics of micro-vibrations plays a fundamental role in the investigation of microelectromechanical systems (MEMS). However, it remains a challenge for achieving both a wide bandwidth and a low noise due to the high photodetector noise and electromagnetic interference at GHz frequencies. Here, we propose a pulsed laser interferometry system with an adaptable switch to image GHz vibrations based on stroboscopic mixing, while measuring lower-frequency vibrations based on the homodyne scheme. The noise power spectral density is shown in both regions from DC to 10 GHz with an average noise down to 30.8 fm/√Hz at GHz frequencies, which holds the highest resolution to the best of our knowledge. Vibrational amplitude and phase mappings of a kHz comb-drive resonator, a GHz piezoelectric transducer, and a GHz film bulk acoustic resonator are presented with animated visualizations and k-space analysis, paving a new paradigm for the first time to image and analyze various MEMS devices of a bandwidth spanning 10 orders of magnitude.

2.
Drug Metab Dispos ; 49(4): 305-313, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33526515

RESUMO

To develop a functional alternative hepatocyte model for primary human hepatocytes (PHHs) with proliferative property, essential drug metabolic, and transporter functions, proliferating human hepatocytes (ProliHHs) expanded from PHHs were fully characterized in vitro. Herein, ProliHHs generated from multiple PHHs donors could be expanded more than 200-fold within four passages and maintained their metabolic or transporter capacities partially. Furthermore, ProliHHs were able to regain the mature hepatic property after three-dimensional (3D) culture. Particularly, the downregulated mRNA expression and function of three major cytochrome P450 (P450) enzymes (CYP1A2, CYP2B6, and CYP3A4) in the proliferating process (ProliHHs-P) could be recovered by 3D culture. The metabolic variabilities across different PHHs donors could be inherited to their matured ProliHHs (ProliHHs-M). The intrinsic clearances of seven major P450 enzymes in ProliHHs-M correlated well (r = 0.87) with those in PHHs. Also, bile canaliculi structures could be observed in sandwich-cultured ProliHHs (SC-ProliHHs), and the biliary excretion index of four probe compounds [cholyl-lys-fluorescein, 5-(and-6)-carboxy-2', 7'-dichlorofluorescein diacetate (CDF), deuterium-labeled sodium taurocholate acid, and rosuvastatin] in SC-ProliHHs (>10%) were close to sandwich-cultured PHHs. More importantly, both ProliHHs-P and ProliHHs-M could be used to evaluate hepatotoxicity. Therefore, these findings demonstrated that the 3D and sandwich culture system could be used to recover the metabolic and transporter functions in ProliHHs for clearance prediction and cholestasis risk assessment, respectively. Together, ProliHHs could be a promising substitute for PHHs in drug metabolism, transport, and hepatotoxicity screening. SIGNIFICANCE STATEMENT: This report describes the study of drug metabolic capacities, efflux transporter functions, and toxicity assessments of proliferating human hepatocytes (ProliHHs). The metabolic variability in different primary human hepatocyte donors could be inherited by their matured ProliHHs derivatives. Also, ProliHHs could form canalicular networks in sandwich culture and display biliary excretion capacities. More importantly, both the proliferative and maturation statuses of ProliHHs could be used to evaluate hepatotoxicity. Together, ProliHHs were feasible to support drug candidate screening in hepatic metabolism, disposition, and toxicity.


Assuntos
Proliferação de Células/efeitos dos fármacos , Citotoxinas/toxicidade , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Taxa de Depuração Metabólica/efeitos dos fármacos , Preparações Farmacêuticas/administração & dosagem , Proliferação de Células/fisiologia , Células Cultivadas , Humanos , Taxa de Depuração Metabólica/fisiologia , Microscopia de Contraste de Fase/métodos
3.
J Environ Manage ; 300: 113798, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34562819

RESUMO

The resuspension and sedimentation of particulate matter and the release of nutrients from sediment are important factors affecting the eutrophication of shallow lakes. The capture and removal of particles rich in nitrogen, phosphorus, and other nutrients at the bottom of lakes is of great significance for improving the management and eutrophication status of lakes. This study investigated the feasibility of applying lake bottom trap technology in seven different locations in Lake Chaohu, which is the fifth largest freshwater lake in China. The results showed that the trap in the western part of Lake Chaohu had the highest sedimentation rate and could capture most of the nutrients. The sedimentation rates were higher in spring and summer than in autumn and winter. The bottom trap effectively collected and preserved chlorophyll a, organic matter, total nitrogen, and total phosphorus. The trap per meter length (15-20 m wide) could catch 20.7-27.6 m3 of particles rich in nutrients with a water content of 50-70%, organic matter content of 281.9-375.8 kg, total nitrogen content of 24.5-32.6 kg, and total phosphorus content of 10.5-14 kg. The proposed bottom trap had little impact on the benthic organism system of the lake. The bottom trap technology used in this study could solve the problem of nitrogen, phosphorus, and algae accumulation in lakes and reservoirs, broaden the utility of lake hydrodynamics in environmental pollution control, and provide new ideas and strategies for the control and management of cumulative pollution in shallow lakes and reservoirs.


Assuntos
Sedimentos Geológicos , Lagos , China , Clorofila A , Monitoramento Ambiental , Eutrofização , Nitrogênio/análise , Nutrientes , Fósforo/análise , Tecnologia
4.
Toxicol Appl Pharmacol ; 404: 115169, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32738331

RESUMO

Being endocrine signaling molecules that regulate lipid metabolism and affect energy balance, bile acids are potential drug candidates for non-alcoholic steatohepatitis (NASH). Obeticholic acid (OCA) could improve NASH accompanied by significant side effects. Therefore, it is worthwhile to develop safer and more effective bile acid analogs. In this study, a new bile acid analog A17 was synthesized and its potential anti-NASH effects were assessed in vitro and in vivo. The impact of A17 on steatosis was investigated in the rat primary hepatocytes challenged with oleic acid. It was found that A17 alleviated lipid accumulation by reducing fatty acid (FA) uptake and promoting FA oxidation. The reduction of FA uptake came from inhibiting fatty acid translocase (Cd36) expression. The promotion of FA oxidation came from stimulating the phosphorylation of adenosine monophosphate (AMP)-activated protein kinase alpha (AMPKα). In addition, A17 reduced lipopolysaccharide-induced inflammation in Raw264.7 cells by activating Takeda G protein-coupled receptor 5 (TGR5). In in vivo study, male Golden Syrian hamsters were fed with high fat (HF) diet and then treated with 50 mg/kg/d A17 for 6 weeks. A17 lowered the lipid profiles and liver enzyme levels in serum and improved liver pathological conditions with less side effects compared with OCA. Further studies confirmed that the molecular mechanisms of A17 in vivo were similar to those in vitro. In conclusion, a novel bile acid analog A17 was identified to ameliorate NASH in HF-fed hamsters. The potential mechanisms could be contributed to reducing FA uptake, stimulating FA oxidation and relieving inflammation.


Assuntos
Ácidos e Sais Biliares/farmacologia , Dieta Hiperlipídica/efeitos adversos , Hepatopatia Gordurosa não Alcoólica/induzido quimicamente , Animais , Antígenos CD36/genética , Antígenos CD36/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Regulação da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Hepatócitos/metabolismo , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Células RAW 264.7 , Ratos , Ratos Sprague-Dawley , Receptores Citoplasmáticos e Nucleares/metabolismo
5.
Acta Pharmacol Sin ; 41(11): 1433-1445, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32404983

RESUMO

In general, anti-inflammatory treatment is considered for multiple liver diseases despite the etiology. But current drugs for alleviating liver inflammation have defects, making it necessary to develop more potent and safer drugs for liver injury. In this study, we screened a series of (dihydro-)stilbene or (dihydro-)phenanthrene derivatives extracted from Pholidota chinensis for their potential biological activities. Among 31 compounds, the dihydro-stilbene gigantol exerted most potent protective effects on human hepatocytes against lithocholic acid toxicity, and exhibited solid antioxidative and anti-inflammatory effect in vitro. In mice with CCl4-induced acute liver injury, pre-administration of gigantol (10, 20, 40 mg· kg-1· d-1, po, for 7 days) dose-dependently decreased serum transaminase levels and improved pathological changes in liver tissues. The elevated lipid peroxidation and inflammatory responses in the livers were also significantly alleviated by gigantol. The pharmacokinetic studies showed that gigantol was highly concentrated in the mouse livers, which consisted with its efficacy in preventing liver injury. Using a label-free quantitative proteomic analysis we revealed that gigantol mainly regulated the immune system process in liver tissues of CCl4-treated mice, and the complement and coagulation cascades was the predominant pathway; gigantol markedly inhibited the expression of complement component C9, which was a key component for the formation of terminal complement complex (TCC) C5b-9. These results were validated by immunohistochemistry (IHC) or real time-PCR. Confocal microscopy analysis showed that gigantol significantly inhibited the vascular deposition of TCC in the liver. In conclusion, we demonstrate for the first time that oral administration of gigantol potently relieves liver oxidative stress and inflammation, possibly via a novel mechanism of inhibiting the C5b-9 formation in the liver.


Assuntos
Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico , Bibenzilas/uso terapêutico , Guaiacol/análogos & derivados , Inflamação/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Administração Oral , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/farmacocinética , Antioxidantes/administração & dosagem , Antioxidantes/farmacocinética , Bibenzilas/administração & dosagem , Bibenzilas/farmacocinética , Tetracloreto de Carbono , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/patologia , Complexo de Ataque à Membrana do Sistema Complemento/antagonistas & inibidores , Guaiacol/administração & dosagem , Guaiacol/farmacocinética , Guaiacol/uso terapêutico , Hepatócitos/efeitos dos fármacos , Humanos , Inflamação/patologia , Peroxidação de Lipídeos/efeitos dos fármacos , Ácido Litocólico , Fígado/patologia , Masculino , Camundongos Endogâmicos ICR , Fenantrenos/farmacologia , Fenantrenos/uso terapêutico , Proteoma/metabolismo , Ratos Sprague-Dawley , Estilbenos/farmacologia , Estilbenos/uso terapêutico
6.
Acta Pharmacol Sin ; 41(1): 129-137, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31341258

RESUMO

Rheumatoid arthritis patients can be prescribed a combination of immunosuppressive drug leflunomide (LEF) and the antiviral drug acyclovir to reduce the high risk of infection. Acyclovir is a substrate of organic anion transporter (OAT) 1/3 and multidrug resistance-associated protein (MRP) 2. Considering the extraordinarily long half-life of LEF's active metabolite teriflunomide (TER) and the kidney injury risk of acyclovir, it is necessary to elucidate the potential impact of LEF on the disposition of acyclovir. Here we used a specific MRP inhibitor MK571 and probenecid (OAT1/3 and MRP2 inhibitor) to assess the effects of MRP2 and OAT1/3 on the pharmacokinetics and tissue distribution of acyclovir in rats. We showed that LEF and probenecid, but not MK571 significantly increased the plasma concentration of acyclovir. However, kidney and liver exposures of acyclovir were increased when coadministered with LEF, probenecid or MK571. The kidney/plasma ratio of acyclovir was increased to approximately 2-fold by LEF or probenecid, whereas it was increased to as much as 14.5-fold by MK571. Consistently, these drugs markedly decreased the urinary excretion of acyclovir. TER (0.5-100 µmol/L) dose-dependently increased the accumulation of acyclovir in MRP2-MDCK cells with an IC50 value of 4.91 µmol/L. TER (5 µmol/L) significantly inhibited the uptake of acyclovir in hOAT1/3-HEK293 cells. These results suggest that LEF/TER increased the kidney accumulation of acyclovir by inhibiting the efflux transporter MRP2, which increased its kidney/plasma ratio and renal injury risk. However, the inhibitory effects of LEF/TER on OAT1/3 reduced the tubular cells' uptake of acyclovir and increased the plasma concentration.


Assuntos
Aciclovir/farmacocinética , Rim/metabolismo , Leflunomida/farmacologia , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores , Proteína 1 Transportadora de Ânions Orgânicos/antagonistas & inibidores , Transportadores de Ânions Orgânicos Sódio-Independentes/antagonistas & inibidores , Aciclovir/administração & dosagem , Aciclovir/metabolismo , Administração Intravenosa , Animais , Células Cultivadas , Crotonatos/administração & dosagem , Crotonatos/metabolismo , Crotonatos/farmacologia , Cães , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Hidroxibutiratos , Leflunomida/administração & dosagem , Leflunomida/metabolismo , Células Madin Darby de Rim Canino/efeitos dos fármacos , Células Madin Darby de Rim Canino/metabolismo , Masculino , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Nitrilas , Proteína 1 Transportadora de Ânions Orgânicos/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Probenecid/administração & dosagem , Probenecid/metabolismo , Probenecid/farmacologia , Propionatos/administração & dosagem , Propionatos/metabolismo , Propionatos/farmacologia , Quinolinas/administração & dosagem , Quinolinas/metabolismo , Quinolinas/farmacologia , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual , Toluidinas/administração & dosagem , Toluidinas/metabolismo , Toluidinas/farmacologia
7.
iScience ; 27(4): 109500, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38715941

RESUMO

Cell therapy using proliferating human hepatocytes (ProliHHs) is an effective treatment approach for advanced liver diseases. However, rapid and accurate identification of high-quality ProliHHs from different donors is challenging due to individual heterogeneity. Here, we developed a machine learning framework to integrate single-cell Raman spectroscopy from multiple donors and identify different stages of ProliHHs. A repository of more than 14,000 Raman spectra, consisting of primary human hepatocytes (PHHs) and different passages of ProliHHs from six donors, was generated. Using a sliding window algorithm, potential biomarkers distinguishing the different cell stages were identified through differential analysis. Leveraging machine learning models, accurate classification of cell stages was achieved in both within-donor and cross-donor prediction tasks. Furthermore, the study assessed the relationship between donor and cell numbers and its impact on prediction accuracy, facilitating improved quality control design. A similar workflow can also be extended to encompass other cell types.

8.
Chemosphere ; 307(Pt 4): 136081, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35995189

RESUMO

Bottom traps capture and preserve nutrient-rich mobile bottom sediments by forming a weak hydrodynamic environment. In this study, Lake Chaohu, a large shallow lake in China, was considered the research object, and the influence of trap at the bottom of the lake on the physical, chemical, and biological characteristics of sediments and water were analysed by combining on-site monitoring and laboratory analysis. The results showed that the hydrodynamic intensity was attenuated by more than 65% at the bottom of the trap compared with that of the upper surface of the water body under different weather conditions, forming an obviously weak hydrodynamic environment. The weak dynamic environment and large sedimentation rate at the bottom of the trap were beneficial to the sedimentation and storage of fine particles that adsorb nutrients, such as nitrogen and phosphorus, in the water. Owing to the increase in local water depth, a low-temperature and low-dissolved oxygen environment was formed inside the trap. The abundance and diversity of microorganisms in the sediments inside the trap were reduced, and the abundance of nitrifying and denitrifying bacteria in the sediment was reduced by approximately 50%, indicating an environment favourable for nitrogen accumulation in the sediment in the trap. Therefore, the environment inside the bottom trap is favourable for capturing the high nutrient-rich particulate matter in the water, which provides theoretical support for use of the lake bottom traps for controlling the endogenous pollution of shallow lakes.


Assuntos
Lagos , Poluentes Químicos da Água , China , Monitoramento Ambiental , Sedimentos Geológicos/química , Lagos/química , Nitrogênio/análise , Nutrientes/análise , Oxigênio/análise , Material Particulado/análise , Fósforo/análise , Água/análise , Poluentes Químicos da Água/análise
9.
J Biomed Mater Res B Appl Biomater ; 110(9): 2015-2027, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35301798

RESUMO

A FEFEFKFK (FEK, F, phenylalaninyl; E, glutamyl; K, lysinyl)-based self-assembling peptide hydrogel (FEK-SAPH) was developed to replace sandwich culture (SC) for improved culture of primary hepatocytes in vitro. Under neutral conditions, FEK self-assembles to form ß-sheet nanofibers, which in turn form FEK-SAPH. For the culture of rat primary hepatocytes (RPH), the use of FEK-SAPH simplified operation steps and promoted excellent cell-cell interactions while maintaining the SC-related RPH polarity trend. Compared with SC, FEK-SAPH cultured RPH for 14 days, the bile duct network was formed, the secretion of albumin and urea was improved, and the metabolic clearance rate based on cytochrome P450 (CYPs) was comparable. In FEK-SAPH culture, the expression level of the biliary efflux transporter bile salt export pump increased by 230.7%, while the biliary excretion index value of deuterium-labeled sodium taurocholate (d8-TCA) differed slightly from the SC value (72% and 77%, respectively, p = .0195). The inhibitory effect of cholestasis drugs on FEK-SAPH was significantly higher than that of SC. In FEK-SAPH, hepatoprotective drugs were more effective in antagonizing hepatotoxicity induced by lithocholic acid (LCA). FEK-SAPH cultured RPH with hepatoprotective drugs can better recover from LCA-induced damage. In summary, FEK-SAPH can be used as a substitute for SC for pharmacokinetic screening to evaluate the drug absorption, disposition, metabolism, excretion, and toxicity (ADMET) in hepatocytes.


Assuntos
Hepatócitos , Hidrogéis , Animais , Transporte Biológico , Células Cultivadas , Hepatócitos/metabolismo , Hidrogéis/metabolismo , Hidrogéis/farmacologia , Peptídeos/farmacologia , Ratos
10.
Cell Prolif ; 55(4): e13147, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34936148

RESUMO

'Requirements for Primary Human Hepatocyte' is the first set of guidelines on Primary Human Hepatocyte in China, jointly drafted and agreed upon by experts from the Chinese Society for Stem Cell Research. This standard specifies the technical requirements, test methods, test regulations, instructions for use, labelling requirements, packaging requirements, storage requirements and transportation requirements for Primary Human Hepatocyte, which is applicable to the quality control for Primary Human Hepatocyte. It was originally released by the China Society for Cell Biology on 9 January 2021. We hope that publication of these guidelines will promote institutional establishment, acceptance and execution of proper protocols and accelerate the international standardization of Primary Human Hepatocyte for applications.


Assuntos
Hepatócitos , China , Humanos
11.
Sci Total Environ ; 781: 146756, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-33798898

RESUMO

Large hydraulic infrastructures have been constructed globally to address water challenges. Past studies have well documented their effects on downstream aquatic ecosystems, which have included disrupting hydrological regimes as well as nutrient delivery, cycling and mediating processes that affect primary production. However, how these infrastructure operations affect lake ecosystems where the infrastructures are situated remains poorly understood. In the present study, we used a three-dimensional hydrodynamic-biogeochemical lake model to quantify the potential effects of large lake sluice operations under extreme high water levels on current structure and water quality parameters of Lake Chaohu in China. We designed and simulated multiple operation strategies based on actual operation curves during the 2016 extreme rainfall season. The model successfully captured the water quality dynamics of Lake Chaohu during both the calibration and validation phases. Our results indicate that higher lake water release rates led to overall accelerations of the current velocity; however, the deceleration of along-shore current velocity along the shorelines was also evident. Higher release rates also resulted in rapid rises ammonium nitrogen (NH4-N), total nitrogen (TN) and total phosphorous (TP) concentrations in the eastern lake basin, as well as a lake-wide rise of chlorophyll-a (Chla) concentration. When the lake sluice was operated at its full capacity, mean concentrations of these four parameters increased by 5.21%, 5.58%, 9.6% and 7.46%, respectively. Modeling results demonstrate that the effects of lake sluice operations were still quite pronounced for four months after the operations. Modeling results also revealed that higher release rate during the operation phase may help decease TN and TP concentrations during the subsequent period. This study provides a useful perspective on how to support the planning and operation of large infrastructures in the face of climate change induced extreme events.

12.
Adv Sci (Weinh) ; 8(19): e2101188, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34382351

RESUMO

Although liver-humanized animals are desirable tools for drug development and expansion of human hepatocytes in large quantities, their development is restricted to mice. In animals larger than mice, a precondition for efficient liver humanization remains preliminary because of different xeno-repopulation kinetics in livers of larger sizes. Since rats are ten times larger than mice and widely used in pharmacological studies, liver-humanized rats are more preferable. Here, Fah-/- Rag2-/- IL2rg-/- (FRG) rats are generated by CRISPR/Cas9, showing accelerated liver failure and lagged liver xeno-repopulation compared to FRG mice. A survival-assured liver injury preconditioning (SALIC) protocol, which consists of retrorsine pretreatment and cycling 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC) administration by defined concentrations and time intervals, is developed to reduce the mortality of FRG rats and induce a regenerative microenvironment for xeno-repopulation. Human hepatocyte repopulation is boosted to 31 ± 4% in rat livers at 7 months after transplantation, equivalent to approximately a 1200-fold expansion. Human liver features of transcriptome and zonation are reproduced in humanized rats. Remarkably, they provide sufficient samples for the pharmacokinetic profiling of human-specific metabolites. This model is thus preferred for pharmacological studies and human hepatocyte production. SALIC may also be informative to hepatocyte transplantation in other large-sized species.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Hepatócitos/metabolismo , Hidrolases/metabolismo , Subunidade gama Comum de Receptores de Interleucina/metabolismo , Fígado/metabolismo , Proteínas Nucleares/metabolismo , Animais , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Humanos , Hidrolases/genética , Subunidade gama Comum de Receptores de Interleucina/genética , Proteínas Nucleares/genética , Ratos
13.
Water Res ; 185: 116162, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32810742

RESUMO

Correcting the systematic bias and quantifying uncertainty associated with the operational water quality forecasts are imperative works for risk-based environmental decision making. This work proposes a post-processing method for addressing both bias correction and total uncertainty quantification for daily forecasts of water quality parameters derived from dynamical lake models. The post-processing is implemented based on a Bayesian Joint Probability (BJP) modeling approach. The BJP model uses a log-sinh transformation to normalize the raw forecasts and corresponding observations, and uses a bivariate Gaussian distribution to characterize the dependence relationship. The posterior distribution of the transformation parameters is inferenced through Metropolis Monte Carlo Markov chain sampling; it generates unbiased probabilistic forecasts that account for uncertainties from all sources. The BJP is used to post-processing raw daily forecasts of dissolved oxygen (DO), ammonium nitrogen (NH), total phosphorus (TP) and total nitrogen (TN) concentrations of Lake Chaohu, the fifth largest lake in China with lead times from 0 to 5 days. Results suggest that an average 93.1% forecast bias has been removed by BJP. The root mean square error in probability skill scores range from 5.8% for NH to 68.2% for TP, and the non-parametric bootstrapping test suggests that 67.7% forecasts are significantly improved averaged across all sampling sites, water quality parameters and lead times. The probabilities of the calibrated forecasts are reasonably consistent with the observed relative frequencies, and have appropriate spread and thus correctly quantify forecast uncertainty. The BJP post-processing method used in this study can be a useful operational tool that help to better realize the potential of water quality forecasts derived from dynamical models.


Assuntos
Lagos , Qualidade da Água , Teorema de Bayes , Calibragem , China , Monitoramento Ambiental , Fósforo/análise , Incerteza
14.
Environ Sci Pollut Res Int ; 27(33): 41488-41502, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32686044

RESUMO

Nutrient retention is an important process in lake nutrient cycling of lakes and can mitigate lake eutrophication. However, little is known about temporal lake nutrient retention efficiency and it varies due to changes in hydrological, ecological, and nutrient inputs to lake waters. Quantitative information about seasonal lake N and P retention is critical for developing strategies to reduce eutrophication in lake systems. This study investigated TN and TP retention efficiencies and retention masses using water and mass balance calculations, and statistically analyzed the seasonal variability of nutrient retention in Lake Chaohu, China, from 2014 to 2018. Lake Chaohu experienced large amounts of external loads inputs (23.2 g N m-2 year-1 and 1.3 g P m-2 year-1), and approximately 58% TN and 48% TP were retained annually. The lake acted more as a sink for N than for P. The mean annual TP retention efficiency decreased (P < 0.05) over the study period, indicating that TP retention capacity was gradually exceeded. Seasonal variability of TN and TP retention efficiency was high and ranged from - 18.7 to 144.1% and from - 58.8 to 170.7%, respectively, over the five study years. The internal P loads over the study period were equivalent to roughly 9% of the total external loads. The annual nutrient retention efficiency of TN and TP increased with hydraulic residence time, while water temperature was an essential factor for the contrasting seasonal variation patterns of TN and TP retention efficiencies.


Assuntos
Lagos , Fósforo , China , Monitoramento Ambiental , Eutrofização , Nitrogênio/análise , Fósforo/análise
15.
Sci Total Environ ; 687: 218-231, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31207512

RESUMO

The socioeconomic benefits associated with informative water quality forecasts for large lakes are becoming increasingly evident. However, it remains an enormous challenge to produce forecasts of water quality variables that are accurate enough to meet public demand. In this study, we developed and evaluated a new forecast framework for real-time forecasting of daily dissolved oxygen (DO), ammonium nitrogen (NH), total phosphorus (TP) and total nitrogen (TN) concentrations at lead times from one to six days for Lake Chaohu, the fifth largest freshwater lake in China. The forecast framework is based on a 3-D hydrodynamic ecological model referred to as EcoLake. We used hydrological, meteorological and water quality data from multiple sources to generate initial conditions and forcing functions. Solar radiation and inflows from tributaries which are not readily available were calculated using forecasted cloud cover and rainfall. Forecast skill was evaluated based on 122 forecasts produced on different days in 2017 and for each of the 12 sampling sites. Results indicate that the skill of the forecast framework varies considerably across water quality variables, sampling sites, and lead times. Generally, the forecast framework is more skillful than the persistence forecasts, which use the most recent observations as forecasts. The TN forecasts tend to be the most skillful with a mean RMSE skill score of 28.5% averaged across the six lead times. The DO forecasts tend to have the lowest skill with an average value of 10.9%. Model sensitivity experiments further revealed that errors in the raw air temperature and wind speed forecasts have a noticeable impact on the overall skill of DO and NH forecasts. The forecast framework proposed here could be a useful operational forecasting tool to enhance the effectiveness of the drinking water supply and public health protection based on the water quality management of Lake Chaohu.


Assuntos
Monitoramento Ambiental/métodos , Poluição da Água/estatística & dados numéricos , China , Previsões , Hidrodinâmica , Hidrologia , Lagos , Modelos Teóricos , Nitrogênio/análise , Fósforo/análise , Qualidade da Água
16.
Sci Total Environ ; 673: 272-280, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-30995582

RESUMO

A novel multi-cathode, single-anode system integrating a sediment microbial fuel cell -based biosensor was developed for in-situ, continuous, and online monitoring of dissolved oxygen (DO) concentrations along various depths of lake water. The signal feedback mechanism was evaluated based on a relationship between voltage and DO concentration at corresponding depths. With an external resistance of 1000 Ω, a linear relationship was found (regression coefficient, R2 = 0.9576) between voltage and DO in the range of 0-9 mg L-1. The sensor performance was further optimized under various influence factors. The results of indoor experiments indicated that the optimal anode to single cathode area ratio was 11:1. The sensor signal could also be significantly influenced by organic matter content in sediment; thus, the addition of 5% organic matter could obtain a stable anode potential and a high voltage output. Furthermore, the sensor was operated in-situ for 67 days in a lake environment, which also led to a good correlation between the voltage and DO (R2 = 0.8897). Thus, this integrated system has great potential as an early-warning program to help identify environmental risks in aquatic environments.


Assuntos
Fontes de Energia Bioelétrica , Monitoramento Ambiental/métodos , Oxigênio/análise , Técnicas Biossensoriais , Eletrodos , Sedimentos Geológicos , Lagos/química , Sistemas On-Line , Águas Residuárias
17.
Oxid Med Cell Longev ; 2015: 903782, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26273426

RESUMO

Multidrug resistance-associated protein 1 (MRP1) plays a protective role in the etiology and progression of chronic obstructive pulmonary disease (COPD) which results from oxidative stress and inflammation of lung injury. The lower functional MRP1 activity is related to COPD development. Our previous study showed that Allyl isothiocyanate (AITC) induced the expression and activity of MRP1 in a dose-dependent manner. However, which signaling pathway contributes to the upregulation of MRP1 by AITC is unclear. In this study, signaling pathway specific inhibitors were used to examine the mechanism of AITC. We found that JNK inhibitor SP600125 treatment decreased MRP1 mRNA expression in 16HBE14o- cells. But the ERK inhibitor U0126 or PI3K/Akt inhibitor LY294002 produced no obvious effect. The AITC-induced increase of MRP1 mRNA expression was abolished by cotreatment of SP600125, while it was not obviously affected by U0126 or LY294002. Furthermore, AITC acivates the JNK signaling pathway in 16HBE14o- cells. Finally, we found that JNK pathway mediated the upregulation of AITC-induced expression and function of MRP1. Taken together, our results indicated that AITC increased the expression and the activity of MRP1 via a JNK-dependent pathway. ERK and PI3K signaling pathway were not involved in the expression of MRP1 mRNA.


Assuntos
Brônquios/patologia , Células Epiteliais/metabolismo , Isotiocianatos/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Sistema de Sinalização das MAP Quinases/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Brônquios/citologia , Linhagem Celular Tumoral , Humanos , Transdução de Sinais , Regulação para Cima
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