Showing papers by "Nanjing University published in 2009"
TL;DR: The results clearly indicate that the metal-free g-C(3)N(4) has good performance in photodegradation of organic pollutant.
Abstract: The g-C3N4 photocatalyst was synthesized by directly heating the low-cost melamine. The methyl orange dye (MO) was selected as a photodegrading goal to evaluate the photocatalytic activity of as-prepared g-C3N4. The comparison experiments indicate that the photocatalytic activity of g-C3N4 can be largely improved by the Ag loading. The strong acid radical ion (SO42− or NO3−) can promote the degrading rate of MO for g-C3N4 photocatalysis system. The MO degradation over the g-C3N4 is mainly attributed to the photoreduction process induced by the photogenerated electrons. Our results clearly indicate that the metal-free g-C3N4 has good performance in photodegradation of organic pollutant.
2,362 citations
TL;DR: A facile approach to the synthesis of high quality graphene nanosheets in large scale through electrochemical reduction of exfoliated graphite oxide precursor at cathodic potentials (completely reduced potential: -1.5 V) is reported.
Abstract: Graphene can be viewed as an individual atomic plane extracted from graphite, as unrolled single-walled carbon nanotube or as an extended flat fullerene molecule. In this paper, a facile approach to the synthesis of high quality graphene nanosheets in large scale through electrochemical reduction of exfoliated graphite oxide precursor at cathodic potentials (completely reduced potential: −1.5 V) is reported. This method is green and fast, and will not result in contamination of the reduced material. The electrochemically reduced graphene nanosheets have been carefully characterized by spectroscopic and electrochemical techniques in comparison to the chemically reduced graphene-based product. Particularly, FTIR spectra indicate that a variety of the oxygen-containing functional groups have been thoroughly removed from the graphite oxide plane via electrochemical reduction. The chemically converted materials are not expected to exhibit graphene’s electronic properties because of residual defects. Indeed, th...
2,065 citations
01 Apr 2009
TL;DR: Experiments show that the proposed algorithms, BalanceCascade and EasyEnsemble, have better AUC scores than many existing class-imbalance learning methods and have approximately the same training time as that of under-sampling, which trains significantly faster than other methods.
Abstract: Undersampling is a popular method in dealing with class-imbalance problems, which uses only a subset of the majority class and thus is very efficient. The main deficiency is that many majority class examples are ignored. We propose two algorithms to overcome this deficiency. EasyEnsemble samples several subsets from the majority class, trains a learner using each of them, and combines the outputs of those learners. BalanceCascade trains the learners sequentially, where in each step, the majority class examples that are correctly classified by the current trained learners are removed from further consideration. Experimental results show that both methods have higher Area Under the ROC Curve, F-measure, and G-mean values than many existing class-imbalance learning methods. Moreover, they have approximately the same training time as that of undersampling when the same number of weak classifiers is used, which is significantly faster than other methods.
1,586 citations
TL;DR: Several widely-used adsorption kinetic models are reviewed and it is believed that the review is of certain significance and improvement for adsorptive kinetic modeling.
Abstract: Adsorption is one of the most widely applied techniques for environmental remediation. Its kinetics are of great significance to evaluate the performance of a given adsorbent and gain insight into the underlying mechanisms. There are lots of references available concerning adsorption kinetics, and several mathematic models have been developed to describe adsorption reaction and diffusion processes. However, these models were frequently employed to fit the kinetic data in an unsuitable or improper manner. This is mainly because the boundary conditions of the associated models were, to a considerable extent, ignored for data modeling. Here we reviewed several widely-used adsorption kinetic models and paid more attention to their boundary conditions. We believe that the review is of certain significance and improvement for adsorption kinetic modeling.
1,339 citations
TL;DR: In this article, the authors used the Very Long Baseline Array and the Japanese VLBI Exploration of Radio Astronomy project to measure trigonometric parallaxes and proper motions of masers found in high-mass star-forming regions across the Milky Way.
Abstract: We are using the Very Long Baseline Array and the Japanese VLBI Exploration of Radio Astronomy project to measure trigonometric parallaxes and proper motions of masers found in high-mass star-forming regions across the Milky Way. Early results from 18 sources locate several spiral arms. The Perseus spiral arm has a pitch angle of 16 degrees +/- 3 degrees, which favors four rather than two spiral arms for the Galaxy. Combining positions, distances, proper motions, and radial velocities yields complete three-dimensional kinematic information. We find that star-forming regions on average are orbiting the Galaxy approximate to 15 km s(-1) slower than expected for circular orbits. By fitting the measurements to a model of the Galaxy, we estimate the distance to the Galactic center R(0) = 8.4 +/- 0.6 kpc and a circular rotation speed Theta(0) = 254 +/- 16 km s(-1). The ratio Theta(0)/R(0) can be determined to higher accuracy than either parameter individually, and we find it to be 30.3 +/- 0.9 km s(-1) kpc(-1), in good agreement with the angular rotation rate determined from the proper motion of Sgr A*. The data favor a rotation curve for the Galaxy that is nearly flat or slightly rising with Galactocentric distance. Kinematic distances are generally too large, sometimes by factors greater than 2; they can be brought into better agreement with the trigonometric parallaxes by increasing Theta(0)/R(0) from the IAU recommended value of 25.9 km s(-1) kpc(-1) to a value near 30 km s(-1) kpc(-1). We offer a "revised" prescription for calculating kinematic distances and their uncertainties, as well as a new approach for defining Galactic coordinates. Finally, our estimates of Theta(0) and Theta(0)/R(0), when coupled with direct estimates of R(0), provide evidence that the rotation curve of the Milky Way is similar to that of the Andromeda galaxy, suggesting that the dark matter halos of these two dominant Local Group galaxy are comparably massive.
1,167 citations
University of Toronto1, University of Turin2, Imperial College London3, Leicester General Hospital4, John Radcliffe Hospital5, Université de Montréal6, University of Washington7, LSU Health Sciences Center Shreveport8, Leiden University9, Columbia University10, Case Western Reserve University11, Mayo Clinic12, University of Amsterdam13, Vanderbilt University14, Western Infirmary15, German Cancer Research Center16, Johns Hopkins University17, St. Vincent's Health System18, Scott & White Hospital19, University of Florida20, University of North Carolina at Chapel Hill21, University of Alabama at Birmingham22, Jikei University School of Medicine23, The Chinese University of Hong Kong24, Nanjing University25, Austral University of Chile26, Juntendo University27, Peking University28, Erasmus University Rotterdam29, Wakayama Medical University30
TL;DR: In this article, a new classification for IgA nephropathy is presented by an international consensus working group and the goal of this new system was to identify specific pathological features that more accurately predict risk of progression of renal disease.
994 citations
TL;DR: This review summarizes recently published information on the types, distributions, and horizontal transfer of ARGs in various aquatic environments, as well as the molecular methods used to detect environmental ARGs, including specific and multiplex PCR, real-time PCR, DNA sequencing, and hybridization based techniques.
Abstract: The use of antibiotics may accelerate the development of antibiotic resistance genes (ARGs) and bacteria which shade health risks to humans and animals. The emerging of ARGs in the water environment is becoming an increasing worldwide concern. Hundreds of various ARGs encoding resistance to a broad range of antibiotics have been found in microorganisms distributed not only in hospital wastewaters and animal production wastewaters, but also in sewage, wastewater treatment plants, surface water, groundwater, and even in drinking water. This review summarizes recently published information on the types, distributions, and horizontal transfer of ARGs in various aquatic environments, as well as the molecular methods used to detect environmental ARGs, including specific and multiplex PCR (polymerase chain reaction), real-time PCR, DNA sequencing, and hybridization based techniques.
851 citations
University of Oxford1, Imperial College London2, Université de Montréal3, University of Washington4, University of Turin5, Leicester General Hospital6, LSU Health Sciences Center Shreveport7, Leiden University8, University of Toronto9, Columbia University10, Case Western Reserve University11, Mayo Clinic12, University of Amsterdam13, Vanderbilt University14, Western Infirmary15, German Cancer Research Center16, Johns Hopkins University17, St. Vincent's Health System18, Scott & White Hospital19, University of Florida20, University of North Carolina at Chapel Hill21, University of Alabama at Birmingham22, Jikei University School of Medicine23, The Chinese University of Hong Kong24, Nanjing University25, Austral University of Chile26, Juntendo University27, Peking University28, Erasmus University Rotterdam29, Wakayama Medical University30
TL;DR: A unique approach for the pathological classification of a glomerular disease, IgA nephropathy, is developed, in which renal pathologists first undertook extensive iterative work to define pathologic variables with acceptable inter-observer reproducibility.
779 citations
TL;DR: The remarkablyStrong adsorption of tetracycline to the carbon nanotubes and to graphite can be attributed to the strong adsorptive interactions (van der Waals forces, pi-pi electron-donor-acceptor interactions, cation-pi bonding) with the graphene surface.
Abstract: Significant concerns have been raised over the presence of antibiotics including tetracyclines in aquatic environments. We herein studied single-walled carbon nanotubes (SWNT) and multi-walled carbon nanotubes (MWNT) as potential effective adsorbents for removal of tetracycline from aqueous solution. In comparison, a nonpolar adsorbate, naphthalene, and two other carbonaceous adsorbents, pulverized activated carbon (AC) and nonporous graphite, were used. The observed adsorbent-to-solution distribution coefficient (Kd, L/kg) of tetracycline was in the order of 10(4)-10(6) L/kg for SWNT, 10(3)-10(4) L/kg for MWNT, 10(3)-10(4) L/kg for AC, and 10(3)-10(5) L/kg for graphite. Upon normalization for adsorbent surface area, the adsorption affinity of tetracycline decreased in the order of graphite/ SWNT > MWNT >> AC. The weaker adsorption of tetracycline to AC indicates that for bulky adsorbates adsorption affinity is greatly affected by the accessibility of available adsorption sites. The remarkably strong adsorption of tetracycline to the carbon nanotubes and to graphite can be attributed to the strong adsorptive interactions (van der Waals forces, pi-pi electron-donor-acceptor interactions, cation-pi bonding) with the graphene surface. Complexation between tetracycline and model graphene compounds (naphthalene, phenanthrene, pyrene) in solution phase was verified by ring current-induced 1H NMR upfield chemical shifts of tetracycline moieties.
676 citations
TL;DR: It is found that mechanical unloading of wildtype mice caused decrease of Wnt/β‐catenin signaling activity accompanied by upregulation of Sost, and sclerostin suppressed the activity of osteoblast and viability of osteoblasts and osteocytes, indicating sclerOSTin is a promising target for preventing disuse osteoporosis.
Abstract: Reduced mechanical stress leads to bone loss, as evidenced by disuse osteoporosis in bedridden patients and astronauts. Osteocytes have been identified as major cells responsible for mechanotransduction; however, the mechanism underlying the response of bone to mechanical unloading remains poorly understood. In this study, we found that mechanical unloading of wildtype mice caused decrease of Wnt/beta-catenin signaling activity accompanied by upregulation of Sost. To further analyze the causal relationship among these events, Sost gene targeting mice were generated. We showed that sclerostin selectively inhibited Wnt/beta-catenin in vivo, and sclerostin suppressed the activity of osteoblast and viability of osteoblasts and osteocytes. Interestingly, Sost(-/-) mice were resistant to mechanical unloading-induced bone loss. Reduction in bone formation in response to unloading was also abrogated in the mutant mice. Moreover, in contrast to wildtype mice, Wnt/beta-catenin signaling was not altered by unloading in Sost(-/-) mice. Those data implied that sclerostin played an essential role in mediating bone response to mechanical unloading, likely through Wnt/beta-catenin signaling. Our findings also indicated sclerostin is a promising target for preventing disuse osteoporosis.
584 citations
TL;DR: It is reported that impairment of bone marrow mesenchymal stem cells and their associated osteoblastic niche deficiency contribute in part to the pathogenesis of SLE‐like disease in MRL/lpr mice.
Abstract: Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease that, despite the advances in immunosuppressive medical therapies, remains potentially fatal in some patients, especially in treatment-refractory patients. Here, we reported that impairment of bone marrow mesenchymal stem cells (BMMSCs) and their associated osteoblastic niche deficiency contribute in part to the pathogenesis of SLE-like disease in MRL/lpr mice. Interestingly, allogenic BMMSC transplantation (MSCT) is capable of reconstructing the bone marrow osteoblastic niche and more effectively reverses multiorgan dysfunction when compared with medical immunosuppression with cyclophosphamide (CTX). At the cellular level, MSCT, not CTX treatment, was capable to induce osteoblastic niche reconstruction, possibly contributing to the recovery of regulatory T-cells and reestablishment of the immune homeostasis. On the basis of the promising clinical outcomes in SLE mice, we treated four CTX/glucocorticoid treatment-refractory SLE patients using allogenic MSCT and showed a stable 12-18 months disease remission in all treated patients. The patients benefited an amelioration of disease activity, improvement in serologic markers and renal function. These early evidences suggest that allogenic MSCT may be a feasible and safe salvage therapy in refractory SLE patients.
TL;DR: The present study provides the first evidences that miR-143 is significant in suppressing colorectal cancer cell growth through inhibition of KRAS translation.
Abstract: Dysregulated expression of microRNAs (miRNAs) is associated with a variety of diseases, including colorectal cancer By comparing more than 200 miRNAs in 13 pairs of matched colorectal cancer and normal adjacent tissue samples through qRT-PCR and microarray analysis, we found a widespread disruption of miRNA expression during colorectal tumorigenesis In particular, among a panel of presumed targets generated by in silico analysis that may interact with these aberrantly expressed miRNAs, KRAS oncogene has been further experimentally validated as the target of miR-143 First, an inverse correlation between KRAS protein and miR-143 in vivo was found Second, KRAS expression in Lovo cells was significantly abolished by treatment with miR-143 mimic, whereas miR-143 inhibitor increased KRAS protein level Third, luciferase reporter assay confirmed that miR-143 directly recognize the 3'-untranslated region of KRAS transcripts Four, Lovo cells treated with miR-143 inhibitor showed a stimulated cell proliferation, whereas miR-143 overexpression had an opposite effect Finally, inhibition of KRAS expression by miR-143 inhibits constitutive phosphorylation of ERK1/2 Taken together, the present study provides the first evidences that miR-143 is significant in suppressing colorectal cancer cell growth through inhibition of KRAS translation
TL;DR: These findings define DNMT3A as both a reader and a writer of repressive epigenetic marks, thereby directly linking histone and DNA methylation in gene silencing.
Abstract: Mammalian gene silencing is established through methylation of histones and DNA, although the order in which these modifications occur remains contentious. Using the human beta-globin locus as a model, we demonstrate that symmetric methylation of histone H4 arginine 3 (H4R3me2s) by the protein arginine methyltransferase PRMT5 is required for subsequent DNA methylation. H4R3me2s serves as a direct binding target for the DNA methyltransferase DNMT3A, which interacts through the ADD domain containing the PHD motif. Loss of the H4R3me2s mark through short hairpin RNA-mediated knockdown of PRMT5 leads to reduced DNMT3A binding, loss of DNA methylation and gene activation. In primary erythroid progenitors from adult bone marrow, H4R3me2s marks the inactive methylated globin genes coincident with localization of PRMT5. Our findings define DNMT3A as both a reader and a writer of repressive epigenetic marks, thereby directly linking histone and DNA methylation in gene silencing.
TL;DR: A simple one-dimensional model of an acoustic diode formed by coupling a superlattice with a strongly nonlinear medium is numerically demonstrated and the effectiveness of theoustic diode is proved despite its simplicity.
Abstract: We numerically demonstrate a simple one-dimensional model of an acoustic diode formed by coupling a superlattice with a strongly nonlinear medium. The first numerical observation is presented of a significant rectifying effect on the acoustic energy flux within particular ranges of frequencies. By studying the underlying rectifying mechanism and the parameter dependence of the rectifying efficiency, the effectiveness of the acoustic diode is proved despite its simplicity. We also briefly discuss possible schemes of the experimental realization of this model as well as devising more efficient models.
TL;DR: In the past decades, polymeric adsorbents have been emerging as highly effective alternatives to activated carbons for pollutants removal and subsequent recovery from industrial effluents as discussed by the authors, which opened up the new opportunities of their application in deep removal of inorganic pollutants from waters.
TL;DR: An Unequal Cluster-based Routing (UCR) protocol is proposed that mitigates the hot spot problem in multihop sensor networks, and achieves an obvious improvement on the network lifetime.
Abstract: Clustering provides an effective method for prolonging the lifetime of a wireless sensor network. Current clustering algorithms usually utilize two techniques; selecting cluster heads with more residual energy, and rotating cluster heads periodically to distribute the energy consumption among nodes in each cluster and extend the network lifetime. However, they rarely consider the hot spot problem in multihop sensor networks. When cluster heads cooperate with each other to forward their data to the base station, the cluster heads closer to the base station are burdened with heavier relay traffic and tend to die much faster, leaving areas of the network uncovered and causing network partitions. To mitigate the hot spot problem, we propose an Unequal Cluster-based Routing (UCR) protocol. It groups the nodes into clusters of unequal sizes. Cluster heads closer to the base station have smaller cluster sizes than those farther from the base station, thus they can preserve some energy for the inter-cluster data forwarding. A greedy geographic and energy-aware routing protocol is designed for the inter-cluster communication, which considers the tradeoff between the energy cost of relay paths and the residual energy of relay nodes. Simulation results show that UCR mitigates the hot spot problem and achieves an obvious improvement on the network lifetime.
TL;DR: In this paper, a phononic crystal in an acoustic “atom” scale has been proposed and some important characteristics such as acoustic band structure and negative refraction have been investigated in acoustic materials and devices.
TL;DR: The results showed that the photodegradation of RhB is enhanced significantly when EO is introduced into the P-25/RhB system, and it can be deduced that dissolved O(2) plays a crucial role in dye photodegrading and the O(*-) anion is possibly the major active oxygen species.
Abstract: Visible light-induced degradation of rhodamine B (RhB) and eosin Y (EO) in a heterogeneous TiO2 P-25/EO/RhB system was investigated in the present work. The results showed that the photodegradation of RhB is enhanced significantly when EO is introduced into the P-25/RhB system. Under optimal conditions (50 mg P-25, 20 mg L−1 EO), RhB (4 mg L−1) almost decomposed completely after 35 min of visible light irradiation, though EO was photodegraded simultaneously. The possible photodegradation mechanism was studied by the examination of active species HO•, O2•− anions, or dye radical cations through adding their scavengers such as methanol, t-butanol, benzoquinone, EDTA, and the I− anion. In addition, the electron paramagnetic resonance (EPR) spin trapping technique was also used to monitor the active oxygen species formed in the photocatalytic process. Combined with the contrastive experiments under different atmospheres (N2-purged or air) and in different systems, it can be deduced that dissolved O2 plays a c...
TL;DR: It was found that catalyst heating temperature significantly influenced the photocatalytic activity of the catalyst in which crystal water may played an important role, and the original sample exhibited higher activity than the heated samples did.
Abstract: The photocatalytic degradation of rhodamine B (RhB) over NaBiO3 under visible light irradiation was investigated in this study. RhB (20 mg/L) was almost completely decolorized in 30 min in given co...
TL;DR: This paper proposes a method called Mlnb which adapts the traditional naive Bayes classifiers to deal with multi-label instances and achieves comparable performance to other well-established multi- label learning algorithms.
TL;DR: It is expected this Au NPs-based Hg(2+) sensor will be a promising candidate for field detection of environmentally toxic mercury and exhibits excellent selectivity over a spectrum of interference metal ions.
Abstract: We report a highly sensitive electrochemical sensor for the detection of Hg2+ ions in aqueous solution by using a thymine (T)-rich, mercury-specific oligonucleotide (MSO) probe and gold nanoparticles (Au NPs)-based signal amplification. The MSO probe contains seven thymine bases at both ends and a “mute” spacer in the middle, which, in the presence of Hg2+, forms a hairpin structure via the Hg2+-mediated coordination of T−Hg2+−T base pairs. The thiolated MSO probe is immobilized on Au electrodes to capture free Hg2+ in aqueous media, and the MSO-bound Hg2+ can be electrochemically reduced to Hg+, which provides a readout signal for quantitative detection of Hg2+. This direct immobilization strategy leads to a detection limit of 1 μM. In order to improve the sensitivity, MSO probe-modified Au NPs are employed to amplify the electrochemical signals. Au NPs are comodified with the MSO probe and a linking probe that is complementary to a capture DNA probe immobilized on gold electrodes. We demonstrated that t...
TL;DR: Current data show that NBD-TPEA staining can be a reliable approach for the intact in vivo Zn(2+) imaging of zebrafish larva as well as for the clarification of subcellular distribution of Zn (2+) in vitro.
Abstract: The UV- and sensor-induced interferences to living systems pose a barrier for in vivo Zn2+ imaging. In this work, an intramolecular charge transfer (ICT) fluorophore of smaller aromatic plane, 4-amino-7-nitro-2,1,3-benzoxadiazole, was adopted to construct visible light excited fluorescent Zn2+ sensor, NBD-TPEA. This sensor demonstrates a visible ICT absorption band, a large Stokes shift, and biocompatibility. It emits weakly (Φ = 0.003) without pH dependence at pH 7.1−10.1, and the λex and λem are 469 (e469 = 2.1 × 104 M−1 cm−1) and 550 nm, respectively. The NBD-TPEA displays distinct selective Zn2+-amplified fluorescence (Φ = 0.046, e469 = 1.4 × 104 M−1 cm−1) with emission shift from 550 to 534 nm, which can be ascribed to the synergic Zn2+ coordination by the outer bis(pyridin-2-ylmethyl)amine (BPA) and 4-amine. The Zn2+ binding ratio of NBD-TPEA is 1:1. By comparison with its analogues NBD-BPA and NBD-PMA, which have no Zn2+ affinity, the outer BPA in NBD-TPEA should be responsible for the Zn2+-induced...
TL;DR: In this paper, two methods of reducing the storage capacitance in the ac/dc power supplies for light emitting diode (LED) lighting were proposed to achieve a long power suppliespsila lifetime.
Abstract: This paper proposes two methods of reducing the storage capacitance in the ac/dc power supplies for light emitting diode (LED) lighting. In doing so, film capacitors can be adopted instead of electrolytic capacitors to achieve a long power suppliespsila lifetime. The voltage ripple of the storage capacitor is intentionally increased to reduce the storage capacitance. The method of determining the storage capacitance for ensuring that the boost power factor correction converter operates normally in the whole input voltage range is also discussed. For the purpose of further reducing the storage capacitance, a method of injecting the third harmonic current into the input current flow is proposed. While ensuring that the input power factor is always higher than 0.9 to comply with regulation standards such as ENERGY STAR, the storage capacitance can be reduced to 65.6% of that with an input power factor of 1. A 60-W experimental prototype is built to verify the proposed methods.
TL;DR: Bi(2)WO(6) was successfully synthesized by a facile hydrothermal method, and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and BET, showing mainly square-plate-like morphologies with a short edge and the average crystalline size was in the range of 50-150 nm.
TL;DR: In this paper, the authors used the LA-ICPMS zircon U-Pb ages for a gneiss and five granites from the Tianhou, Danzhu, Xiaji and Lizhuang plutons to show that magmatism and metamorphism took place between 1888 and 1855-Ma.
TL;DR: In this paper, the authors used a regional geological investigation on various Mesozoic basins and a recently compiled 1:1,500,000 geological map of Southeast China Block (SECB) basins.
TL;DR: In this article, a general control strategy for series-parallel systems, which decouples the output voltage control loop and the sharing control loop, is proposed, and three modularization architectures are proposed for input-series output-series connected systems.
Abstract: This paper investigates DC/DC conversion systems constructed from connecting multiple converter modules in series and/or parallel at both the input and output sides. Control strategies aiming at achieving proper sharing of the voltage and/or current at the input or output sides are studied in detail. The relationship between sharing of input voltages/currents and that of output voltages/currents is studied. In particular, the inherent stability of control operations applied at the input side and the output side is analyzed. Based on the analysis, a general control strategy for series-parallel systems, which decouples the output voltage control loop and the sharing control loop, is proposed. Furthermore, three modularization architectures are proposed for input-series-output-parallel (ISOP), input-parallel-output-series (IPOS), and input-series-output-series (ISOS) connected systems. These architectures enjoy full advantages of modularization and no external controller is needed to coordinate the sharing control for the individual modules. Experimental prototypes are built and tested to validate the general control strategy and the proposed modularization architectures.
TL;DR: It is shown that the cytotoxicity of QDs can be modulated through elaborate surface coatings and that the CdTe/CdS/ZnS core-shell-shell structured QDs directly synthesized in aqueous phase are highly promising biological fluorescent probes for cellular imaging.
TL;DR: In order to investigate the contamination levels of trace metals, surface water samples were collected from six regions along Yangtze River in Nanjing Section and Hazard Quotients of all metals were lower than unity, except As and Cd, suggesting that those two metals have potential adverse effects on local residents.
Abstract: In order to investigate the contamination levels of trace metals, surface water samples were collected from six regions along Yangtze River in Nanjing Section. The concentrations of trace metals (As, B, Ba, Be, Cd, Cr, Cu, Fe, Pb, Li, Mn, Mo, Ni, Sb, Se, Sn, Sr, V and Zn) were determined using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Total concentrations of the metals in the water samples ranged from 825.1 to 950.4 μg/L. The result was compared with international water quality guidelines. Seven metals levels were above the permissible limit as prescribed by guidelines. A preliminary risk assessment was then carried out to determine the human health risk via calculating Hazard Quotient and carcinogenic risk of the metals. Hazard Quotients of all metals were lower than unity, except As. The carcinogenic risk of As and Cd was higher than 10−6, suggesting that those two metals have potential adverse effects on local residents.