Refine search
Results 1-10 of 18
Associations of multiple plasma metals with incident type 2 diabetes in Chinese adults: The Dongfeng-Tongji Cohort
2018
Yuan, Yu | Xiao, Yang | Yu, Yanqiu | Liu, Yiyi | Feng, Wei | Qiu, Gaokun | Wang, Hao | Liu, Bing | Wang, Jing | Zhou, Lue | Liu, Kang | Xu, Xuedan | Yang, Handong | Li, Xiulou | Qi, Lu | Zhang, Xiaomin | He, Meian | Hu, Frank B. | Pan, An | Wu, Tangchun
The long-term associations between multiple metals and incident diabetes are uncertain. We aimed to examine the relationship between plasma concentrations of 23 metals and the incidence of type 2 diabetes among Chinese senior adults. We quantified fasting plasma concentrations of 23 metals by inductively coupled plasma mass spectrometry among 1039 incident diabetes cases and 1039 controls (age and sex matched) nested in a prospective study, the Dongfeng-Tongji cohort. Both cases and controls were free of diabetes at baseline (2008–2010), incident diabetes were identified using the following criteria: fasting glucose ≥ 7.0 mmoL/l; or hemoglobin A1c (HbA1c) ≥ 6.5%; or self-reported physician diagnosis of diabetes or use of anti-diabetic medication during the follow-up visits in 2013. In the conditional logistic regression models, the multivariable adjusted ORs (95% CIs) of diabetes across quartiles (Q1–Q4) of metal concentrations were as follows: titanium, 1.00, 0.92, 1.31, 1.38 (1.00–1.91, Ptrend = 0.011); selenium, 1.00, 1.08, 1.45, 1.27 (0.93–1.74, Ptrend = 0.05); and antimony, 1.00, 0.79, 0.77, 0.60 (0.44–0.83, Ptrend = 0.002). Arsenic was significantly associated with diabetes in the crude model (ORs comparing extreme quartiles 1.30; 1.02–1.65; Ptrend = 0.006), but was not significant after adjustment for socio-demographic factors. No significant associations were found for other metals. In conclusion, titanium and selenium were positively while antimony was negatively associated with incident diabetes.
Show more [+] Less [-]Rationally designed core-shell and yolk-shell magnetic titanate nanosheets for efficient U(VI) adsorption performance
2018
Yinling, | Song, Shuang | Wang, Xiangxue | Niu, Fenglei | Ma, Ran | Yu, Shujun | Wen, Tao | Chen, Yuantao | Hayat, Tasawar | Alsaedi, Ahmed | Wang, Xiangke
The hierarchical core-shell and yolk-shell magnetic titanate nanosheets (Fe3O4@TNS) were successfully synthesized by employing magnetic nanoparticles (NPs) as interior core and intercrossed titanate nanostructures (NSs) as exterior shell. The as-prepared magnetic Fe3O4@TNS nanosheets had high specific areas (114.9 m2 g−1 for core-shell Fe3O4@TNS and 130.1 m2 g−1 for yolk-shell Fe3O4@TNS). Taking advantage of the unique multilayer structure, the nanosheets were suitable for eliminating U(VI) from polluted water environment. The sorption was strongly affected by pH values and weakly influenced by ionic strength, suggesting that the sorption of U(VI) on Fe3O4@TNS was mainly dominated by ion exchange and outer-sphere surface complexion. The maximum sorption capacities (Qmax) calculated from the Langmuir model were 68.59, 121.36 and 264.55 mg g−1 for core-shell Fe3O4@TNS and 82.85, 173.01 and 283.29 mg g−1 for yolk-shell Fe3O4@TNS, at 298 K, 313 K and 328 K, respectively. Thermodynamic parameters (ΔH0, ΔS0 and ΔG0) demonstrated that the sorption process was endothermic and spontaneous. Based on X-ray photoelectron spectroscopy (XPS) analyses, the sorption mechanism was confirmed to be cation-exchange between interlayered Na+ and UO22+. The yolk-shell Fe3O4@TNS had more extraordinary sorption efficiency than core-shell Fe3O4@TNS since the yolk-shell structure provided internal void space inside the titanate shell to accommodate more exchangeable active sites. The flexible recollection and high efficient sorption capacity made core-shell and yolk-shell Fe3O4@TNS nanosheets promising materials to eliminate U(VI) or other actinides in wastewater cleanup applications.
Show more [+] Less [-]Chemical and morphological characterization of respirable suspended particulate matter (PM10) and associated heath risk at a critically polluted industrial cluster
2018
Panda, Smaranika | Shiva Nagendra, S.M.
Present study investigated the physical and chemical characteristics of PM₁₀ at one of the critically polluted industrial clusters of India (Manali, Tamil Nadu). Chemical and morphological analysis were carried out for 103 PM₁₀ samples collected using high volume sampler during winter, summer, monsoon and post monsoon seasons (November 2014 to May 2016). The daily average PM₁₀ concentration at the study area exceeded the national ambient air quality standards (NAAQS) by 100, 68, 55, 78% of time during winter, summer, monsoon and post monsoon seasons, respectively. Results indicated dominance of SO₄²⁻ (5481 ng/m³) ions followed by NO₃²⁻ (4445 ng/m³), Na⁺ (4115 ng/m³) and NH₄⁺ (3993 ng/m³) with a strong correlation among SO₄²⁻, NO₃²⁻ and NH₄⁺ suggesting their common origin from industrial and vehicular exhausts. High SO₄²⁻ to NO₃²⁻ ratio indicated dominance of stationary sources at the study area. Metals such as Na, Fe, Ca, K and Al constituent 96% of total elements at the study site. Among toxic metals high concentration of Zn (681 ng/m³) followed by Ba (295 ng/m³), Mn (24.67 ng/m³), V (17.05 ng/m³) and Ni (14.37 ng/m³) were observed. Further, carcinogenic elements such as Cr, Cd, As, Ni and Pb were also observed at the study site with highest cancer risk for Cr. Factor analysis revealed the contributions from industrial processes, heavy oil combustion and petroleum refineries, crustal, marine aerosol and road dust re-suspension and metal industries. Further, morphological analysis showed various metal (C, Si, Fe, Mn, Ti, V) rich particles with irregular, spherical and elongated shapes.
Show more [+] Less [-]Interplay between elemental imbalance-related PI3K/Akt/mTOR-regulated apoptosis and autophagy in arsenic (III)-induced jejunum toxicity of chicken
2018
Wang, Yu | Zhao, Hongjing | Shao, Yizhi | Liu, Juanjuan | Li, Jinglun | Xing, Mingwei
Arsenic trioxide (As₂O₃), the most toxic form of arsenic found in foodstuffs, is considered a carcinogen for human and animal. But many of the events that occur during its passage through the gastrointestinal tract are uncharted in birds. This study assesses the toxic effect on the jejunum of chicken which subchronically exposed to diets that contain As₂O₃ (0, 0.625, 1.25, 2.5 mg/kg body weight) for 90 days. Electron microscopy, TdT-mediated dUTP nick-end labeling (TUNEL), qPCR, and Western blot were performed. The results showed that mitochondrial fusion and apoptosis inhibiting genes had degressive trends, whereas mitochondrial fission and apoptosis activating genes presented heightened expressions in the treatment group compared with the control (P < 0.05). Subsequently, significant inhibition in PI3K/AKT/mTOR signaling was observed. Moreover, the expression of autophagy markers (LC3-II/LC3-I, Beclin-1) increased time and dose-dependently. Additionally, metabolic disorders of trace elements were detected evidenced by their significant decreases (aluminum, silicon, calcium, manganese, strontium, titanium, lithium, boron, cobalt, mercury, chromium) and increases (arsenic, cadmium, selenium, lead, nickel) on 90 days using inductively coupled plasma mass spectrometer (ICP-MS). It is possible that the changes of trace elements have a hand in the come on and development of arsenism. Taken together, we conjectured that, in chicken jejunum, arsenic led to redistribution of trace elements, promoting apoptosis via regulating mitochondrial dynamics, leading to autophagy through PI3K/AKT/mTOR signal pathways.
Show more [+] Less [-]The removal of silver nanoparticle by titanium tetrachloride and modified sodium alginate composite coagulants: floc properties, membrane fouling, and floc recycle
2018
Wang, Ziyang | Wang, Yan | Yu, Cong | Zhao, Yanxia | Fan, Meixia | Gao, Baoyu
In this study, a modified sodium alginate (MSA) composited with TiCl₄ was used to treat the synthetic Ag nanoparticles (AgNPs) water in coagulation-ultrafiltration process. The floc properties and membrane fouling of TiCl₄ and MSA composite coagulants (TiCl₄ + MSA) were investigated by a laser diffraction instrument and ultrafiltration fouling model. The recycle of the AgNP-containing flocs was evaluated by XRD and photocatalytic experiments. The results showed that TiCl₄ + MSA could achieve better coagulation performance than TiCl₄ alone with AgNP and DOC removal up to 97 and 59% at the optimum condition (pH = 5 and dosage = 12 mg TiCl₄/L). TiCl₄ + MSA produced larger and looser flocs than TiCl₄ and TiCl₄ + SA composite coagulant (TiCl₄ + SA), which was benefit for the inhibition of subsequence membrane fouling. The strongly attached external fouling resistance (Rₑf₋ₛ) and the reversible internal fouling resistance (Rᵢf₋ᵣ₎ of TiCl₄ + MSA were only 43 and 39.2% of those achieved by TiCl₄ at the optimal coagulation condition. Besides, the adopted AgCl-TiO₂ could be recycled from AgNP-containing flocs. And MSA could promote the form of TiO₂ anatase. It gives us a possible way for silver nanoparticle recycle.
Show more [+] Less [-]Early plant growth and bacterial community in rhizoplane of wheat and flax exposed to silver and titanium dioxide nanoparticles
2018
Gorczyca, Anna | Przemieniecki, Sebastian W. | Kurowski, Tomasz | Oćwieja, Magdalena
Silver and titanium dioxide nanoparticles (AgNPs and TiO₂NPs) are highly useful, but they are also a significant reason for concern as they exert toxicity. The goal of research was to assess the role of three kinds of NPs in concentrations of 100 mg L⁻¹ on early growth plants (wheat, flax) and bacterial community in rhizoplane. Titanium (IV) oxide anatase (TiO₂NPs1) and titanium (IV) oxide nanopowder (TiO₂NPs2) are commercial products. A suspension of AgNPs was prepared via a procedure of reduction with tannic acid. The response of Monocot and Dicot growth form plants to the tested NPs was different. Germination and seedling growth of wheat treated with TiO₂NPs1 was better. The response of flax to NPs was noted as an increase of chlorophyll content. The bacterial community in wheat rhizoplane was not significantly modified, but there was a declining trend. In turn, a difference in the surface charge of NPs had an influence on the total bacterial community in Dicot rhizoplane. Positively charged TiO₂NPs2 significantly decreased the quantity of total bacteria in contrast to negatively charged AgNPs and TiO₂NPs1 which increased it. A qualitative analysis did not confirm the influence of the surface charge of NPs on an increase/decrease in the quantity of Pseudomonas and Bacillus bacteria, but did show that there was no toxicity of the tested NPs to the plant growth-promoting bacteria community. The rhizoplane microbiome was dependent on the species of plant, and the bacteria found in the communities are sensitive to NPs to a varying degree.
Show more [+] Less [-]Enhanced algae removal by Ti-based coagulant: comparison with conventional Al- and Fe-based coagulants
2018
Xu, Jie | Zhao, Yanxia | Gao, Baoyu | Zhao, Qian
The water eutrophication caused by cyanobacteria seasonally proliferates, which is a hot potato to be resolved for water treatment plants. This study firstly investigated coagulation performance of titanium tetrachloride (TiCl₄) for Microcystis aeruginosa synthetic water treatment. Results show complete algal cell removal by TiCl₄ coagulation without damage to cell membrane integrity even under harsh conditions; 60 mg/L TiCl₄ was effective in removing the microcystins up to 85%. Furthermore, besides having stronger UV₂₅₄ removal capability and the higher removal of fluorescent substances over Al- and Fe-based coagulants, TiCl₄ coagulant required more compact coagulation and sedimentation tanks due to its significantly improved floc growth and sedimentation speed. Meanwhile, its’ short hydraulic retention time avoided algal cell breakage and subsequent algal organic matter release. Microcystin concentrations were kept at a low level during sludge storage period, indicating that the TiCl₄ flocs could prevent algal cells from natural lysis. To facilitate water recycling without secondary contamination, the algae-containing sludge after TiCl₄ coagulation ought to be disposed within 12 days at 20 °C and 8 days at 35 °C.
Show more [+] Less [-]Tropidurus torquatus (Squamata: Tropiduridae) as a bioindicator of heavy metal (aluminum and zinc) pollution in Vila Velha, Brazil
2018
Salvador, RaizaMenezes Venturim | Pim, Fernanda | Júnior, HermínioArias Nalini | de Abreu, AdrianaTrópia | Pimentel, ElisângelaFlavia | de Cerqueira, LorenaOliveira | Junior, PauloDias Ferreira | Endringer, DeniseCoutinho
Urbanization is responsible for numerous environmental changes including pollution. Information on the susceptibility of reptiles to environmental contaminants is relatively scarce. Tropidurus torquatus represents a potential bioindicator of heavy metal pollution. Levels of heavy metals in tissues from T. torquatus depend on bioavailability and vary among different populations. The aim of this study was to determine the heavy metal concentration in liver and fat tissue of T. torquatus from three distinct populations in the state of Espírito Santo, Brazil. The study areas included coastal rocky outcrops, dunes, and mountain rocky outcrops; each area had a different climate, vegetation, and level of anthropogenic influence. Fifty-one individuals were captured. Biometrics and sexes were determined, and stomach contents were identified. The tissue samples were digested with nitric acid and analyzed via inductively coupled plasma optical emission spectrometry (ICP-OES) for aluminum (Al), arsenic (As), barium (Ba), cadmium (Cd), chromium (Cr), copper (Cu), lithium (Li), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), strontium (Sr), titanium (Ti), vanadium (V), and zinc (Zn) contents. The concentration of zinc in Tropidurus torquatus was higher in liver than in fat tissue (432 ± 1380 mg kg⁻¹), and that of aluminum was higher in fat tissue (765 ± 1455 mg.kg⁻¹). The animals’ diet may be related to heavy metal contamination. The study suggests that T. torquatus could be used for soil biomonitoring with liver as a bioindicator for aluminum contamination and fat tissue as a bioindicator for zinc contamination. Graphical abstract ᅟ
Show more [+] Less [-]A facile method to prepare translucent anatase thin films in monolithic structures for gas stream purification
2018
Rodrigues-Silva, Caio | Monteiro, Ricardo A. R. | Dezotti, Márcia | Silva, Adrián M. T. | Pinto, Eugénia | Boaventura, Rui A. R. | Vilar, Vítor J. P.
In the present work, a facile method to prepare translucent anatase thin films on cellulose acetate monolithic (CAM) structures was developed. A simple sol–gel method was applied to synthesize photoactive TiO₂ anatase nanoparticles using tetra-n-butyl titanium as precursor. The immobilization of the photocatalyst on CAM structures was performed by a simple dip-coating method. The translucent anatase thin films allow the UV light penetration through the CAM internal walls. The photocatalytic activity was tested on the degradation of n-decane (model volatile organic compound—VOC) in gas phase, using a tubular lab-scale (irradiated by simulated solar light) and pilot-scale (irradiated by natural solar light or UVA light) reactors packed with TiO₂-CAM structures, both equipped with compound parabolic collectors (CPCs). The efficiency of the photocatalytic oxidation (PCO) process in the degradation of n-decane molecules was studied at different operating conditions at lab-scale, such as catalytic bed size (40–160 cm), TiO₂ film thickness (0.435–0.869 μm), feed flow rate (75–300 cm³ min⁻¹), n-decane feed concentration (44–194 ppm), humidity (3 and 40%), oxygen concentration (0 and 21%), and incident UV irradiance (18.9, 29.1, and 38.4 WUV m⁻²). The decontamination of a bioaerosol stream was also evaluated by the PCO process, using Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive) as model bacteria. A pilot-scale unit was operated day and night, using natural sunlight and artificial UV light, to show its performance in the mineralization of n-decane air streams under real outdoor conditions. Graphical abstract Normally graphics abstract are not presented with captions/legend. The diagram is a collection of images that resume the work
Show more [+] Less [-]Drosophila melanogaster as model organism for monitoring and analyzing genotoxicity associated with city air pollution
2018
de Santana, Samuel Lima | Verçosa, Cícero Jorge | de Araújo Castro, Ícaro Fillipe | de Amorim, Érima Maria | da Silva, André Severino | da Rocha Bastos, Thiago Moura | da Silva Neto, Luiz Joaquim | dos Santos, Thiago Oliveira | De França, Elvis Joacir | Rohde, Claudia
This study evaluated the genotoxic potential of atmospheric pollution associated with urbanization using the model organism Drosophila melanogaster and the Comet assay with hemolymph cells. Larvae were exposed to atmospheric compounds in an urban and a rural area in the municipality of Vitória de Santo Antão, Pernambuco, Brazil, for 6 days (from the embryo stage to the third larval stage) in April 2015 and April 2017. The results were compared to a negative environmental control group exposed to a preserved area (Catimbau National Park) and to a negative control exposed to the laboratory room conditions. The Comet assay demonstrated significant genetic damage in the organisms exposed to the urban area compared with those exposed to the rural area and negative control groups. The evidences were supported by particulate matter analysis showing higher photopeaks of chemical elements such as aluminum, silicon, sulfur, potassium, calcium, titanium, and iron, associated to road dust fraction in urban environment. Once again, the results confirm D. melanogaster an ideal bioindicator organism to monitor genotoxic hazard associated with atmospheric pollution.
Show more [+] Less [-]