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1.
Sci Total Environ ; 814: 152813, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34995590

RESUMO

Redox-active biochar has been regarded as an effective additive to promote heterotrophic denitrification, yet little is known about the feasibility of adding biochar for promoting anammox performance. In this study, we investigated the effects of different biochar doses (3-14 g/L; 1.5-7.1 g/g VSS) on anammox performance. Results showed that, in a short term (40 days), biochar could enhance anammox nitrogen removal rate (NRR) and nitrogen removal efficiency (NRE) by 0-18.0% and 0.2%-11.6%, respectively; this enhancement effect increased at 3-10 g biochar/L assays and reached a plateau at 10-14 g biochar/L assays. The optimal biochar dosage was identified to be 10 g/L (5.1 g/g VSS), with the NRR and NRE being 5.6%-18.0% and 4.0%-11.6% higher than those of the control, respectively. The highest specific anammox activity was simultaneously obtained at 10 g biochar/L assay, being 51% higher than that of the control. It revealed that biochar promoted the secretion of extracellular polymeric substances (increased by 30%-40% compared with that of the control) and increased the ratio of extracellular proteins to polysaccharides as well, directly enhancing the extracellular electron transfer capacity (ETC) of anammox biomass. The increased ETC of anammox biomass would further accelerate the metabolic activities of anammox bacteria, and promote the relative abundance of anammox bacteria, i.e., Ca. Brocadia was enriched by 5.8-12.6 folds than that of the control. These results demonstrate that biochar is feasible to enhance anammox activity and nitrogen removal performance, facilitating to a fast startup and enhanced nitrogen removal of anammox system.

2.
Sci Total Environ ; 802: 149695, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34438127

RESUMO

Particle number size distribution (PNSD) is of importance for understanding the mechanisms of particle growth, haze formation and climate impacts. However, the measurements of PNSD aloft in megacities are very limited. Here we report the first simultaneous winter measurements of size-resolved particle number concentrations along with collocated gaseous species and aerosol composition at ground level and 260 m in Beijing. Our study showed that the vertical differences of particle number concentrations between ground level and aloft varied significantly as a function of particle size throughout the study. Further analysis illustrated the impacts of boundary dynamics and meteorological conditions on the vertical differences of PNSD. In particular, the temperature and relative humidity inversions were one of the most important factors by decoupling the boundary layer into different sources and processes. Positive matrix factorization analysis identified six sources of PNSD at both ground level and city aloft. The local source emissions dominantly contributed to Aitken-mode particles, and showed the largest vertical gradients in the city. Comparatively, the regional particles were highly correlated between ground level and city aloft, and the vertical differences were relatively stable throughout the day. Our results point towards a complex vertical evolution of PNSD due to the changes in boundary layer dynamics, meteorological conditions, sources, and processes in megacities.


Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , Pequim , China , Monitoramento Ambiental , Tamanho da Partícula , Material Particulado/análise , Estações do Ano
3.
Water Res ; 210: 117998, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34968878

RESUMO

Iron is a recognized physiological requirement for microorganisms but, for anaerobic ammonium oxidation (anammox) bacteria, its role extends well beyond that of a nutritional necessity. In this study, the function of two typical Fe(III)-minerals (ferrihydrite and magnetite) in anammox processes was evaluated in the absence/presence of Fe(II) by integrated network and metagenomics analyses. Results showed that Fe-(III) minerals addition increased the activity of cellular processes and pathways associated with granule formation, enabling the peak values of particle size to increase by 144% and 115%, respectively. Notably, ferrihydrite (5 mM) enhanced nitrogen removal by 4.8% and 4.1%, respectively, in the short-term and long-term absence of Fe(II). Ferrihydrite also promoted the retention of anammox bacteria affiliated with phylum Planctomycetes in the reactor, contributing to an 11% higher abundance with ferrihydrite amendment when compared with the control (without iron additions) in the short-term absence of Fe(II). Network-based analyses revealed that ferrihydrite facilitated the microbial community to form densely clustered and complex topologies to improve resistance to environmental disturbance (i.e., Fe(II) deficiency), and effectively increased the underlying cooperation and facilitation in the community. Metagenomic analysis revealed that there was limited promotion of anammox central metabolism by the extra addition of Fe(III)-minerals in the presence of Fe(II), highlighting the poor utilization of Fe(III)-minerals by anammox bacteria under Fe(II) sufficiency. This study deepens our understanding of the function of Fe(III)-minerals in anammox systems at the community and functional level, and provides a fundamental basis for developing Fe-based anammox enhancement technologies.

4.
Sci Total Environ ; 806(Pt 3): 151325, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34718000

RESUMO

Sludge floatation is inevitable in anammox granular reactors, which reduces the effective granules participating in anammox reaction and weakens the robust operation of anammox reactors. However, so far, the involved floatation mechanisms as well as the floatation mitigation measurements have not been well proposed. In this study, floating sludge (including irreversibly floating sludge (FSI) and reversibly floating sludge (FSR)) and settled granule sludge (SGS) were collected from an anammox expanded granular sludge bed (EGSB) reactor and compared in terms of morphological, physical, chemical and microbial properties. The particle size ranked FSI > SGS > FSR, and cavities were distinctly observed in FSI due to the gas pockets and cell lysis. Rheological measurements revealed that the storage modulus (represent intensity of sludge) of FSI and SGS were comparable, both of which were approximately1.4 times greater than that of FSR. High storage modulus indicated that the hydraulic shear force in the EGSB was not strong enough to destroy FSI and release the gases trapped in gas pocket, resulting in the irreversible floatation of FSI. Whereas, the dinitrogen gases adhered onto FSR were readily stripped from FSR under hydraulic shearing, which contributed to their reversible floatation property. It is concluded that sludge floatation is resulted from the gas accumulation or gas adhesion onto the sludges, while the sludge floatation reversibility depends on the sludge intensity and hydraulic shear force. Our findings elucidate the floatation properties of anammox sludge via rheological analysis, which will contribute to the proper sludge floatation control and facilitate the optimization of anammox granule fluidization in EGSB reactor.


Assuntos
Reatores Biológicos , Esgotos , Anaerobiose , Gases , Nitrogênio , Oxirredução
5.
Artigo em Inglês | MEDLINE | ID: mdl-34767517

RESUMO

The automatic and accurate segmentation of the prostate cancer from the multi-modal magnetic resonance images is of prime importance for the disease assessment and follow-up treatment plan. However, how to use the multi-modal image features more efficiently is still a challenging problem in the field of medical image segmentation. In this paper, we develop a cross-modal self-attention distillation network by fully exploiting the encoded information of the intermediate layers from different modalities, and the generated attention maps of different modalities enable the model to transfer significant spatial information that contains more details. Moreover, a novel spatial correlated feature fusion module is further employed for learning more complementary correlation and non-linear information of different modality images. We evaluate our model in five-fold cross-validation on 358 MRI images with biopsy confirmed. Without bells and whistles, our proposed network achieves state-of-the-art performance on extensive experiments.

6.
Environ Sci Technol ; 2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34806377

RESUMO

The understanding at a molecular level of ambient secondary organic aerosol (SOA) formation is hampered by poorly constrained formation mechanisms and insufficient analytical methods. Especially in developing countries, SOA related haze is a great concern due to its significant effects on climate and human health. We present simultaneous measurements of gas-phase volatile organic compounds (VOCs), oxygenated organic molecules (OOMs), and particle-phase SOA in Beijing. We show that condensation of the measured OOMs explains 26-39% of the organic aerosol mass growth, with the contribution of OOMs to SOA enhanced during severe haze episodes. Our novel results provide a quantitative molecular connection from anthropogenic emissions to condensable organic oxidation product vapors, their concentration in particle-phase SOA, and ultimately to haze formation.

7.
Huan Jing Ke Xue ; 42(10): 5010-5020, 2021 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-34581145

RESUMO

Focusing on typical mildly saline soil, S1 (EC, 0.62 dS·m-1), and moderately saline soil, S2 (EC, 1.17 dS·m-1), in Hetao Irrigation District of Inner Mongolia, the response of nitrification and denitrification process to salinization degree and the proportion of organic and inorganic nitrogen application were studied. The experimental treatments consisted of(1) no nitrogen(CK), (2) only inorganic nitrogen(U1), and(3) organic nitrogen(U3O1, U1O1, U1O3, and O1) compared to 25%, 50%, 75%, and 100% inorganic nitrogen. The results showed that increasing salinity reduced the soil nitrification potential and increased the soil denitrification capacity. The soil nitrification potential of the S1 soil was 28.81%-69.67% higher than that of the S2 soil, while the denitrification capacity was reduced by 17.16%-88.91%. With an increase in salinity, the AOB abundance and nitrification contribution rate were reduced, but the AOA abundance and nitrification contribution rate were increased. Furthermore, an increase in salinity increased the abundance of nirK and nirS bacteria, and increased N2O/(N2O+N2) production, but reduced the abundance of nosZ. In the S1 soil, the nitrification potential and denitrification capacity of U1O1 were highest, increasing by as much as 18.59% and 15.87%, respectively, compared to the U1 treatment. In the S2 soil, the difference in the soil nitrification potential between the various fertilization treatments was not significant, and the denitrification capacity of the O1 treatment was highest. The S1 and S2 saline soils treated with U1O1 and O1, respectively, had higher AOB gene abundance and nitrification contribution rates, increased nirS and nosZ gene abundances, and significantly reduced N2O/(N2O+N2) product ratios. Our findings suggested that mildly saline soils(120 kg·hm-2 urea+120 kg·hm-2 organic fertilizer) and moderately saline soils(240 kg·hm-2 organic fertilizer) are more conducive to soil nitrification and denitrification processes compared to soils to which inorganic nitrogen is applied alone.


Assuntos
Nitrificação , Solo , Desnitrificação , Nitrogênio , Óxido Nitroso/análise , Microbiologia do Solo
8.
Biotechniques ; 71(3): 465-472, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34350779

RESUMO

Laboratory biosafety has become a core focus in biological analysis, owing to the frequent occurrence of laboratory-acquired infections caused by the leakage of pathogenic microorganisms. For this purpose, the authors developed a safe pretreatment device combining a sealing technique with a direct injection technique. In this study, several bacteria and viruses were used to validate the filtration effect of the invention. Data show that the new device can completely filter bacteria and that the filtration rates for hepatitis B virus and hepatitis C virus reached 94% and 96%, respectively. The results show that the new preparation device can effectively block these pathogens and can improve biological safety and provide powerful protection for technicians.

9.
Entropy (Basel) ; 23(5)2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-34067056

RESUMO

With the increasing demand of location-based services, neural network (NN)-based intelligent indoor localization has attracted great interest due to its high localization accuracy. However, deep NNs are usually affected by degradation and gradient vanishing. To fill this gap, we propose a novel indoor localization system, including denoising NN and residual network (ResNet), to predict the location of moving object by the channel state information (CSI). In the ResNet, to prevent overfitting, we replace all the residual blocks by the stochastic residual blocks. Specially, we explore the long-range stochastic shortcut connection (LRSSC) to solve the degradation problem and gradient vanishing. To obtain a large receptive field without losing information, we leverage the dilated convolution at the rear of the ResNet. Experimental results are presented to confirm that our system outperforms state-of-the-art methods in a representative indoor environment.

10.
Nat Commun ; 12(1): 1993, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33790274

RESUMO

The formation mechanism of aerosol sulfate during wintertime haze events in China is still largely unknown. As companions, SO2 and transition metals are mainly emitted from coal combustion. Here, we argue that the transition metal-catalyzed oxidation of SO2 on aerosol surfaces could be the dominant sulfate formation pathway and investigate this hypothesis by integrating chamber experiments, numerical simulations and in-field observations. Our analysis shows that the contribution of the manganese-catalyzed oxidation of SO2 on aerosol surfaces is approximately one to two orders of magnitude larger than previously known routes, and contributes 69.2% ± 5.0% of the particulate sulfur production during haze events. This formation pathway could explain the missing source of sulfate and improve the understanding of atmospheric chemistry and climate change.

11.
Toxicology ; 456: 152770, 2021 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-33823232

RESUMO

Extensive health studies had declared that exposure to particulate matter (PM) was closely associated with neurodegenerative diseases, i.e. Parkinson's disease (PD). Our aim was to clarify the potential molecular mechanism by which PM2.5 aggravated PD symptoms using in vitro and in vivo PD models. In this study, PC12 cells treated with rotenone (1 µM) and/or PM2.5 (50 µg/mL) for 4 days was used as the in vitro model. C57BL/6 J mice expored to PM2.5 (inhalation, 2.5 mg/kg) and rotenone (intraperitoneal injection, 30 mg/kg) for 28 days was used as the in vivo model. Rapamycin was used to promote the level of autophagy. The results showed that after exposure to PM2.5, the apoptosis of rotenone-treated PC12 cells were increased by increasing the ROS levels and decreasing the levels of mitochondrial membrane potential. In rotenone-treated PC12 cells, exposure to PM2.5 could decrease the expression levels of LC3II and Atg5, and increase the expression level of mTOR, suggesting that PM2.5 exposure inhibited autophagy. Furthermore, the mitophagy related genes, including PINK1 and Parkin, were decreased. At the same time, inhalation of PM2.5 could relieve the behavioral abnormalities of PD mouse induced by rotenone. The levels of inflammatory factors (TNF-α, IL-1ß, and IL-6) were significantly increased. Inhalation of PM2.5 could induce the oxidative stress and apoptosis in the substantia nigra of PD mouse, as well as the key markers of autophagy and mitophagy were also changed, which was consistent with the cell model. Besides, rapamycin would relieve the damaging effect of PM2.5 by triggering autophagy and mitophagy in rotenone-induced PD models. These results indicated that exposure to PM2.5 aggravated the behavioral abnormalities of PD symptoms through increasing oxidative stress, decreasing autophagy and mitophagy, and inducing mitochondria-mediated neuronal apoptosis. These findings not only revealed the effects and mechanism of PM2.5 exposure on PD, but also provided fundamental data that can be exploited to develop environmental safety policies.


Assuntos
Autofagia/efeitos dos fármacos , Exposição por Inalação/efeitos adversos , Mitofagia/efeitos dos fármacos , Transtornos Parkinsonianos/induzido quimicamente , Transtornos Parkinsonianos/metabolismo , Material Particulado/toxicidade , Animais , Autofagia/fisiologia , Inseticidas/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitofagia/fisiologia , Células PC12 , Transtornos Parkinsonianos/patologia , Material Particulado/administração & dosagem , Ratos , Rotenona/toxicidade , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
12.
Oncol Rep ; 45(6)2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33907854

RESUMO

Spindle assembly abnormal protein 6 homolog (SASS6) is crucial for centriole duplication; however, the role of SASS6 in the proliferation of cancer cells remains unclear. In the present study, the expression and functional role of SASS6 in triple negative breast cancer (TNBC) was assessed. Immunohistochemical staining was performed using an anti­SASS6 antibody in TNBC and normal tissues. Lentivirus­mediated RNA interference was used to knockdown SASS6 in MDA­MB­231 TNBC cells. Cell viability was determined using an MTT assay, and cell cycle distribution and apoptosis were measured using flow cytometry. Additionally, PathScan intracellular signaling arrays were used to detect the presence of intracellular signaling molecules. The results revealed that SASS6 expression was increased in TNBC tissues compared with the control tissue. Moreover, SASS6 knockdown significantly suppressed the growth of MDA­MB­231 cells. MDA­MB­231 cell cycle progression was arrested at the G2/M phase and cyclin dependent kinase 1 (CDK1), cyclin B1 and PCNA expression in MDA­MB­231 cells was decreased following SASS6 knockdown. Furthermore, the phosphorylation of STAT3, BAD and rpS6 was reduced following SASS6 knockdown. A strong correlation between SASS6 and CDK1 expression was observed in TNBC tissues based on immunohistochemical staining analysis (R=0.989; P<0.001). In conclusion, the present study revealed the crucial role of SASS6 in promoting MDA­MB­231 cell growth, regulating cell cycle progression and its ability to downregulate the CDK1/cyclin B1 signaling pathway, thus highlighting the potential of SASS6 as a therapeutic target for treatment of TNBC, and merits further investigation in animal models or in preclinical and clinical studies.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Pontos de Checagem da Fase G2 do Ciclo Celular/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias de Mama Triplo Negativas/genética , Proteína Quinase CDC2/metabolismo , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Ciclina B1/metabolismo , Feminino , Técnicas de Silenciamento de Genes , Humanos , Transdução de Sinais/genética , Neoplasias de Mama Triplo Negativas/patologia
13.
Sensors (Basel) ; 21(4)2021 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-33668436

RESUMO

With the rise of location-based services and the rapidly growing requirements related to their applications, indoor localization based on channel state information-multiple-input multiple-output (CSI-MIMO) has become an important research topic. However, indoor localization based on CSI-MIMO has some disadvantages, including noise and high data dimensions. To overcome the above drawbacks, we proposed a novel method of indoor localization based on CSI-MIMO, named SICD. For SICD, a novel localization fingerprint was first designed which can reflect the time-frequency and space-frequency characteristics of CSI-MIMO under a single access point (AP). To reduce the redundancy in the data of CSI-MIMO amplitude, we developed a data dimensionality reduction algorithm. Moreover, by leveraging a log-normal distribution, we calculated the conditional probability of the naive Bayes classifier, which was used to predict the moving object's location. Compared with other state-of-the-art methods, the results of the experiment confirm that the SICD effectively improves localization accuracy.

14.
J Phys Chem A ; 125(18): 3813-3825, 2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-33687210

RESUMO

Oxidants are central species in the atmosphere, where they not only determine secondary particle formation but also impact human health and climate change. In general, they are unstable, highly reactive, and recyclable and have been studied in field observations, laboratory studies, and model simulations. The most widely investigated oxidants, such as OH radicals, O3, and Cl atom, HONO, NO3, N2O5, and Criegee Intermediates (CIs) have attracted more attention recently. Furthermore, secondary particles formed in the oxidations processes impact the particle physicochemical properties, such as hygroscopicity and optical properties and therefore impact the atmospheric radiation balance. Therefore, the newest investigation results of important oxidants (HONO, NO3, N2O5, and CIs) are reviewed in this manuscript, and the environmental effects of secondary particles formed through corresponding oxidation processes are also stated. Furthermore, some perspectives are further discussed in the article.

15.
J Environ Sci (China) ; 102: 185-197, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33637243

RESUMO

Understanding the formation mechanisms of secondary air pollution is very important for the formulation of air pollution control countermeasures in China. Thus, a large-scale outdoor atmospheric simulation smog chamber was constructed at Chinese Research Academy of Environmental Sciences (the CRAES Chamber), which was designed for simulating the atmospheric photochemical processes under the conditions close to the real atmospheric environment. The chamber consisted of a 56-m3 fluorinated ethylene propylene (FEP) Teflon film reactor, an electrically-driven stainless steel alloy shield, an auxiliary system, and multiple detection instrumentations. By performing a series of characterization experiments, we obtained basic parameters of the CRAES chamber, such as the mixing ability, the background reactivity, and the wall loss rates of gaseous compounds (propene, NO, NO2, ozone) and aerosols (ammonium sulfate). Oxidation experiments were also performed to study the formation of ozone and secondary organic aerosol (SOA), including α-pinene ozonolysis, propene and 1,3,5-trimethylbenzene photooxidation. Temperature and seed effects on the vapor wall loss and SOA yields were obtained in this work: higher temperature and the presence of seed could reduce the vapor wall loss; SOA yield was found to depend inversely on temperature, and the presence of seed could increase SOA yield. The seed was suggested to be used in the chamber to reduce the interaction between the gas phase and chamber walls. The results above showed that the CRAES chamber was reliable and could meet the demands for investigating tropospheric chemistry.


Assuntos
Poluentes Atmosféricos , Smog , Aerossóis/análise , Poluentes Atmosféricos/análise , China , Processos Fotoquímicos , Smog/análise
16.
J Environ Sci (China) ; 102: 53-63, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33637265

RESUMO

A distinctive kind of organic carbon aerosol that could absorb ultraviolet-visible radiation is called brown carbon (BrC), which has an important positive influence on radiative budget and climate change. In this work, we reported the absorption properties and potential source of BrC based on a seven-wavelength aethalometer in the winter of 2018-2019 at an urban site of Sanmenxia in Fenwei Plain in central China. Specifically, the mean value of BrC absorption coefficient was 59.6 ± 36.0 Mm-1 at 370 nm and contributed 37.7% to total absorption, which made a significant impact on visibility and regional environment. Absorption coefficients of BrC showed double-peak pattern, and BrC had shown small fluctuations under haze days compared with clean days. As for the sources of BrC, BrC absorption coefficients expressed strong correlations with element carbon aerosols and primary organic carbon aerosols, indicating that most of BrC originated from primary emissions. The linear correlations between trace metal elements (K, As, Fe, Mn, Zn, and Pb) and BrC absorption coefficients further referred that the major sources of BrC were primary emissions, like coal burning, biomass burning, and vehicle emissions. The moderate relationship between BrC absorption coefficients and secondary organic aerosols suggested that secondary production of BrC also played an important role. The 120 hr backward air mass trajectories analysis and concentration-weighted trajectories analysis were also used to investigate potential sources of BrC in and around this area, which inferred most parts of BrC were derived from local emissions.


Assuntos
Poluentes Atmosféricos , Carbono , Aerossóis/análise , Poluentes Atmosféricos/análise , Carbono/análise , China , Monitoramento Ambiental , Material Particulado/análise
17.
Sci Total Environ ; 751: 141620, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32889456

RESUMO

With the development of the economy, anthropogenic emissions in the atmospheric environment increases, and air pollution has caused wide public concern. Vehicle exhaust is an important emission source in the atmosphere, and alkanes are the representative components in it. In this study, the optical properties of secondary organic aerosol (SOA) derived from several C12 alkanes (2-methylundecane, hexylcyclohexane, and cyclododecane) in the absence of NOX were determined. Absorption (imaginary part of the refractive index (RI), k) at 532 nm was negligible for all the derived SOA, and the scattering (real part of RI, n) of the SOA at 532 nm followed the order of cyclododecane SOA < hexylcyclohexane SOA < 2-methylundecane SOA, at both room- (25 °C) and low- (5 °C) temperature. The chemical compositions of the SOA formed were analyzed with an electrospray ionization time-of-flight mass spectrometer (ESI-TOF-MS). The mass spectra showed that the oligomers were generated in the reactions. It was shown that the different reaction pathways (due to various alkane structures) leaded to the difference in SOA chemical composition, which changed the RI values. The low-temperature condition promoted the progress of the oligomerization reaction so that the final RI values also changed. This work suggested that when estimating the radiative forcing of SOA using regional or global models, the structure of the precursors and reaction conditions should be taken into account.

18.
Environ Pollut ; 271: 116329, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33370612

RESUMO

Limited data were on the acute respiratory responses in the elderly in response to personal exposure of particulate matter (PM). In order to evaluate the changes of airway inflammation and pulmonary functions in the elderly in response to individual exposure of particles (PM1.0, PM2.5 and PM10), we analyzed 43 elderly subjects with either asthma, chronic obstructive pulmonary disease (COPD) or Asthma COPD Overlap (ACO) and 40 age-matched subjects without asthma nor COPD in an urban community in Shanghai, China. Data were collected at the baseline and in 6 follow-ups from August 2016 to December 2018, once every 3 months except for the last twice with a 6-month interval. In each follow-up, pulmonary functions, fractional exhaled nitric oxide (FeNO), 7-day continuous personal exposure to airborne particles were measured. Multivariate linear mixed effect regression models were applied to investigate the quantitative changes of pulmonary functions and FeNO in two respective groups. The results showed that on average 4.7 follow-up visits were completed in each participant. In subjects with CRDs, an inter-quartile range (IQR) increase of personal exposure to PM1.0, PM2.5 and PM10 was significantly associated with an average increase of FeNO(Lag1) of 6.7 ppb (95%CI 1.2, 9.9 ppb), 6.2 ppb (95%CI 1.5, 12.0 ppb) and 5.6 ppb (95%CI 1.5, 11.0 ppb), respectively, and an average decrease of FEV1(Lag2) of -3.6 L (95%CI -6.0, -1.1 L), -3.6 L (95%CI -6.4, -0.8 L) and -3.2 L (95%CI -5.8, -0.6 L), respectively, in the single-pollutant model. These associations remained consistent in the two-pollutant models adjusting for gaseous air pollutants. Stratified analysis showed that subjects with lower BMI, females and non-allergies were more sensitive to particle exposure. No robust significant effects were observed in the subjects without CRDs. Our study provided data on the susceptibility of the elderly with CRDs to particle exposure of PM1.0 and PM2.5, and the modification effects by BMI, gender and history of allergies.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Asma , Doença Pulmonar Obstrutiva Crônica , Idoso , Poluentes Atmosféricos/análise , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , China , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Feminino , Humanos , Material Particulado/análise
19.
Anaerobe ; 67: 102295, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33246096

RESUMO

OBJECTIVE: Clostridioides difficile may colonize healthy infants and young children asymptomatically and for the long-term. C. difficile genotypes and the rate and determinants of colonization differ substantially and vary among countries and regions. A 1-year follow-up study was performed to determine the incidence, kinetics and influencing factors of C. difficile intestinal colonization. METHODS: Twenty-nine healthy infants (14 girls and 15 boys) living at home with their parents in Handan City were followed by survey from birth to 1 year of age, specifically from October 2014 through December 2015. C. difficile isolates were typed by PCR ribotyping and analyzed for the presence of toxin genes. RESULTS: During the follow-up study period in the first year of life, 20 of the 29 total enrolled infants acquired C. difficile. A total of 437 fecal samples were obtained, and 111 (25.4%) samples contained C. difficile, including 79 (71.2%) toxigenic strains. The toxigenic isolates comprised six PCR ribotypes, and two PCR ribotypes were identified as nontoxigenic strains. CONCLUSION: Our study showed that C. difficile colonization increase with age during the 12-month period, and the dominant toxigenic types of C. difficile isolates in infants were those involved in long-term colonization. Feeding patterns may affect the dynamic progress of C. difficile colonization.


Assuntos
Portador Sadio/epidemiologia , Clostridioides difficile/classificação , Clostridioides difficile/genética , Infecções por Clostridium/epidemiologia , Biodiversidade , China/epidemiologia , Clostridioides difficile/isolamento & purificação , DNA Bacteriano , Fezes/microbiologia , Comportamento Alimentar , Feminino , Seguimentos , Genótipo , Humanos , Incidência , Lactente , Recém-Nascido , Intestinos/microbiologia , Masculino , Reação em Cadeia da Polimerase , RNA Ribossômico 16S , Ribotipagem
20.
Environ Res ; 194: 110646, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33359458

RESUMO

Anammox bacteria are widely found to grow in bioaggregates form, but the reason for their high aggregation ability remains elusive. In this study, four kinds of sludge, i.e., anammox granules, anaerobic granules, aerobic granules, and partial nitrification flocs, were studied and compared to investigate their differences in adherence properties. We directly explored the adherence properties of sludge samples before and after extracellular polymeric substances (EPS) extraction, using quartz-crystal microbalance technique with dissipation monitoring technique. Results showed that EPS indeed stimulated the adherence properties of all sludge samples. The most striking feature here is that anammox consortia had the highest adhesion rate and mass, and formed the most compact layer on the gold-coated sensor surfaces both before and after EPS extraction among the four sludge samples, indicating their inherent high adhesion ability. The composition and spectral characteristics of EPS samples were also investigated, and it reveals that the relatively high extracellular proteins/polysaccharides ratio of anammox granules (3.2 ± 0.4) rather than total EPS concentration had contributed to their high adhesion ability. The findings are helpful for understanding the adherence properties of anammox bacteria, and will serve as a guide for further researches to exploring the aggregation process of anammox bacteria.


Assuntos
Reatores Biológicos , Nitrogênio , Matriz Extracelular de Substâncias Poliméricas , Nitrificação , Esgotos
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