Computational and experimental studies on band alignment of ZnO/InxGa2-xO3/GaN heterojunctions.

The ZnO/GaN heterojunctions are extensively investigated now, owing to their good luminescent properties and devisable capability to form efficient hybrid structures. An electron-blocking layer inserted into heterojunctions can greatly change their properties. In this work, n-ZnO/ß-InxGa2-xO3/p-GaN heterojunctions have been successfully formed using atomic layer deposition methods. We show that the doping of In can effectively tune the band edges of the heterojunctions. First-principle calculations reveal that the bandgap of bulk ß-InxGa2-xO3 shrinks linearly with the increase in In contents, accompanied by an upward movement of the valence band maximum and a downward movement of the conduction band minimum. As the indium concentrations increase, the valence band offsets show an upward movement at both the InxGa2-xO3/GaN and ZnO/InxGa2-xO3 interfaces, while the conduction band offsets present different trends. A broad, reddish yellow-green emission appears after In doping, which verifies the effect of band alignment. What is more, we show that the amorphization of InxGa2-xO3 can play an important role in tuning the band edge. This work provides access to a series of band offsets tunable heterojunctions and can be used for the further design of direct white light-emitting diodes without any phosphors, based on this structure.

Long Non-Coding RNA HAND2 Antisense RNA 1 Inhibits Colorectal Cancer Development by Sponging microRNA-3118/Leptin Receptor Axis.

OBJECTIVE: This study aimed to examine the function of long non-coding RNA HAND2 antisense RNA 1 (HAND2-AS1) in colorectal cancer (CRC) and explore its underlying mechanism of action. METHODS: HAND2-AS1, microRNA (miR)-3118, and leptin receptor (LEPR) levels were determined using western blot analysis and reverse transcription quantitative polymerase chain reaction (RT-qPCR). RNA-binding protein immunoprecipitation (RIP) and luciferase reporter assays were performed to evaluate the relationship between HAND2-AS1, miR-3118, and LEPR. Overexpression of genes in CRC cell lines was performed by transfection with the overexpression vector or miR-mimic. Cell proliferation, migration, and apoptosis-related protein levels were evaluated using the Cell Counting Kit-8 (CCK-8), Transwell, and western blotting assays. A CRC xenograft mouse model was established to verify the role of HAND2-AS1 in CRC in vivo. RESULTS: In both CRC cell lines and CRC tumor samples the HAND2-AS1 expression was reduced. Upregulation of HAND2-AS1 levels inhibited CRC cell line proliferation and migration, initiated apoptosis, and suppressed the growth of CRC xenografted tumors. In addition, HAND2-AS1 sponges miR-3118, which is up-regulated in CRC. Moreover, miR-3118 overexpression promoted CRC cell line proliferation along with cell migration, but hindered apoptosis of cells, along with altering the consequences of high expression levels of HAND2-AS1 in CRC cells. In addition, miR-3118 can target LEPR, which is downregulated in CRC. The effect of miR-3118 on CRC cells was blocked by LERP overexpression. CONCLUSION: HAND2-AS1 effectively inhibited CRC progression by sponging the miR-3118-LEPR axis. Our results may facilitate the development of therapeutic interventions for CRC.

The structural, electronic and optical properties of four α-Se-based heterostructures with hyperbolic characteristics.

The physical properties and potential applications of two-dimensional (2D) materials can be effectively modulated and enriched by constructing van der Waals heterostructures (VDWHs) with two or more 2D monolayer materials. In this work, by using first-principles calculations based on density functional theory (DFT), we have systematically investigated the structural, electronic and optical properties of four α-Se-based VDWHs, that is, α-Se/Ca(OH)2, α-Se/GaSe, α-Se/h-BN and α-Se/MoS2 VDWHs. The results show that both the band alignment and band gap of these four VDWHs can be effectively modulated by interlayer coupling, biaxial strain and an external electric field. Compared with interlayer coupling and biaxial strain, the external electric field can modulate the electronic properties of these VDWHs more significantly, which makes them exhibit more rich electronic properties. Interestingly, the optical property calculations revealed that both α-Se and the four α-Se-based VDWHs have intrinsic hyperbolic properties. In addition, compared with the individual components, the optical absorption of these four VDWHs in the visible and ultraviolet light regions is significantly enhanced. These results enrich the properties of selenene and selenene-based VDWHs and extend their potential applications in electronic and optoelectronic devices.

CircCDC6 restrains tumor growth and glycolysis energy metabolism in colorectal cancer via regulating miR-3187-3p and downstream PRKAA2.

The aberrant downregulation of circCDC6 in colorectal cancer (CRC) was previously identified by circRNA microarray analysis. However, the detailed role of circCDC6 in CRC is still lacking. We thus investigated the function of circCDC6 in CRC. The expression of circCDC6, miR-3187-3p and PRKAA2 mRNA was checked by real-time quantitative PCR (RT-qPCR). Cell growth was evaluated by MTT, EdU and colony formation assays. Cell apoptosis was evaluated by flow cytometry. Glycolysis was evaluated by glycolysis stress test and lactic acid level. The expression of PRKAA2, HK2 and LDHA proteins was checked by western blotting. The potential binding between miR-3187-3p and circCDC6 or PRKAA2 was confirmed by dual-luciferase reporter assay, RIP assay and pull-down assay. Xenograft model was established in nude mice. CircCDC6 showed poor expression in CRC tumor samples and cells. CircCDC6 ectopic expression repressed CRC cell proliferation, survival and glycolysis energy metabolism. MiR-3187-3p was targeted by circCDC6, and miR-3187-3p depletion also repressed CRC cell growth and glycolysis. PRKAA2 was a downstream target of circCDC6/miR-3187-3p pathway, and circCDC6 upregulated PRKAA2 expression via targeting miR-3187-3p. PRKAA2 knockdown rescued the functional effects of circCDC6 ectopic expression. CircCDC6 overexpression in vivo impeded tumor development in animal models. CircCDC6, acting as a tumor inhibitor, repressed tumor growth and glycolysis metabolism in CRC via targeting the miR-3187-3p/PRKAA2 axis, which partly clarified the role of circCDC6 in CRC.

Formation of stable polonium monolayers with tunable semiconducting properties driven by strong quantum size effects.

Elemental two-dimensional (2D) materials have attracted extraordinary interest compared with other 2D materials over the past few years. Fifteen elements from group IIIA to VIA have been discussed experimentally or theoretically for the formation of 2D monolayers, and the remaining few elements still need to be identified. Here, using first-principles calculations within density functional theory (DFT) and ab initio molecular dynamics simulations (AIMDs), we demonstrated that polonium can form stable 2D monolayers (MLs) with a 1T-MoS2-like structure. The band structure calculations revealed that polonium monolayers possess strong semiconducting properties with a band gap of ∼0.9 eV, and such semiconducting properties can well sustain up to a thickness of 4 MLs with a bandgap of ∼0.1 eV. We also found that polonium monolayers can be achieved through a spontaneous phase transition of ultrathin films with magic thicknesses, resulting in a weaker van der Waals interaction of ∼32 meV Å-2 between each three atomic layers. Also, the underlying physics comes from layered Peierls-like distortion driven by strong quantum size effects. Based on these intriguing findings, a suitable substrate on which the polonium monolayer can be grown through an epitaxial growth technique is proposed for further experiments. Our work not only extends completely the puzzle of elemental 2D monolayer materials from group IIIA to VIA, but also presents a new formation mechanism of 2D materials beyond the database of bulk materials with layered van der Waals interactions.

Equally Spaced Quantum States in van der Waals Epitaxy-Grown Nanoislands.

Pursuing the confinement of linearly dispersive relativistic Fermions is of interest in both fundamental physics and potential applications. Here, we report strong STM evidence for the equally spaced, strikingly sharp, and densely distributed quantum well states (QWSs) near Fermi energy in Pb(111) nanoislands, van der Waals epitaxially grown on graphitized 6H-SiC(0001). The observations can be explained as the quantized energies of confined linearly dispersive [111] electrons, which essentially "simulate" the out-of-plane relativistic quasiparticles. The equally spaced QWSs with an origin of confined relativistic electrons are supported by phenomenological simulations and Fabry-Pérot fittings based on the relativistic Fermions. First-principles calculations further reveal that the spin-orbit coupling strengthens the relativistic nature of electrons near Fermi energy. Our finding uncovers the unique equally spaced quantum states in electronic systems beyond Landau levels and may inspire future studies on confined relativistic quasiparticles in flourishing topological materials and applications in structurally simpler quantum cascade laser.

Do policy burdens induce excessive managerial perks? Evidence from China's stated-owned enterprises.

This paper explores the effect of policy burdens of China's state-owned enterprises (SOEs) on senior executives' excessive perks. The empirical analysis demonstrates that SOE policy burdens are significantly and positively correlated with senior executives' excessive perks, indicating that SOE policy burdens increase agency cost. The results hold after controlling for potential endogeneity. Moreover, we find the following evidences. Strategic policy burdens of SOEs have a significantly greater impact on their senior executives' excessive perks, compared with social policy burdens. The positive impact of SOE policy burdens on excessive perks is significantly weaker in east China due to the higher degree of marketization. The central government's stricter supervision can also alleviate the positive correlation between policy burdens of centrally administered SOEs and senior executives' excessive perks.

Catalytic hydrothermal liquefaction of rice straw for production of monomers phenol over metal supported mesoporous catalyst.

The catalytic (SBA-15, Ni/SBA-15, Al/SBA-15 and Ni-Al/SBA-15) hydrothermal liquefaction (HTL) of rice straw biomass was examined at different temperature with different amount of catalyst in the presence of different solvents. In comparison with water solvent liquefaction, the bio-oil yield significantly increased under alcoholic solvent (ethanol and methanol). The highest bio-oil yield was observed for water (44.3 wt%) with Ni-Al/SBA-15, while for ethanol (56.2 wt%), and for methanol (48.1 wt%) with, Ni/SBA-15 catalyst. The loading of Ni and Al on SBA-15, the acid strength of the catalyst enhanced. Bio-oils yield were analyzed with the help of GC-MS, FT-IR, NMR, GPC and CHNS. From the GC-MS analysis, the main monomeric phenolic compounds were produced, phenol, 4-ethyl-phenol, 2-methoxy-phenol, 2-methoxy-4-ethyl-phenol and Vanillin. It was observed by CHNS and GPC analysis of the bio-oil, compared to the non-catalytic liquefaction reaction, the catalytic liquefaction reaction promotes the hydrogenation/hydrodeoxygenation and produced lower molecular weight bio-oils.

Prevalence of pneumoconiosis among young adults aged 24-44 years in a heavily industrialized province of China.

OBJECTIVES: The purposes of this study were to clarify (i) the prevalence of pneumoconiosis among young adults and (ii) the factors associated with pneumoconiosis among young adults to explore targeted solution for control of pneumoconiosis among young adults (aged 24-44 years). METHODS: The new cases diagnosed from 2001 to 2015 (extracted from the National Occupational Disease and Occupational Health Information Monitoring System) were involved in this research, including information of employer, patient's name, date of birth, gender, date of diagnosis, first year of dust exposure, duration of exposure, aggregation etc RESULTS: A total of 1519 pneumoconiosis cases were diagnosed among young adults (21.6% of overall cases). Silicosis was the most common type with acute process of disease. Compared with overall cases, the young patients had shorter duration of exposure, more stage II/III cases and higher aggravation rate; and were even more concentrated in small and medium enterprises where more migrant workers were employed and insufficient protective measures were used. Without further regulation, the prevalence of pneumoconiosis among young adults would bring not only disease suffering for 3000 individuals and their families, but also an annual economic loss up to 180 million yuan for Hebei province till 2025. CONCLUSIONS: As a typical heavily industrialized province of China, Hebei has severe situation on pneumoconiosis among young adults. Special attention and effort on silica-contacting industries, small and medium enterprises, and migrant workers should be focused in future occupational supervision and regulation among young adults.

A novel nitrogen heterocycle platform-based highly selective and sensitive fluorescence chemosensor for the detection of Al3+ and its application in cell imaging.

In the study, a highly selective and sensitive fluorescence sensor derived from nitrogen heterocycle was synthesized and characterized. By the fluorescence experiments, it was found to show a higher response toward Al3+ than other commonly coexistent metal ions in C2H5OH/H2O media (pH = 7.2). Moreover, the large binding constant (3.44 × 1014 M-1) between Al3+ and the sensor was calculated by fluorescence titration experiment. In addition, the synergistic effect mechanism due to photoinduced electron transfer (PET) and C[double bond, length as m-dash]N isomerization was deduced according to the fluorescence behavior. In addition, the fluorescence imaging in living cells was studied systemically, which exhibited high fluorescence sensing activity toward Al3+.

Hairpin-shaped DNA Templated Copper Nanoparticles for Fluorescence Detection of Adenosine Triphosphate Based on Ligation-mediated Exonuclease Cleavage.

DNA-templated copper nanoparticles (CuNPs) have recently received considerable interest as functional fluorescent probes for biochemical analysis. In this work, a novel ATP-dependent ligation reactions (ATP-DLR) based ATP assay strategy was proposed by using hairpin-shaped (HS) DNA templated CuNPs as a fluorescent probe. Nick sealing by T4 DNA ligase leads to the formation of intact HS DNA, which can resist the exonuclease cleavage and be taken as the template for CuNPs formation, resulting in strong fluorescence. The proposed ATP detection is label free, sensitive and highly selective, and it has good linearity from 0.02 to 4 µM and a detection limit of 7 nM. This strategy is expected to promote the exploitation and application of DNA-templated CuNPs in biochemical and biomedical studies, and holds great promise in fluorescence detection for other ligation-related biomolecules.

C 20 - T carbon: a novel superhard sp (3) carbon allotrope with large cavities.

Through first-principles calculations, we predict a new superhard carbon allotrope named C 20 - T, which possesses a cubic T symmetry with space group No.198(P213). This new carbon allotrope has an all-sp (3) hybridized bonding network with 20 atoms in its primitive unit cell. The dynamic, mechanical, and thermal stabilities of this new carbon phase at zero pressure are confirmed by using a variety of state-of-the-art theoretical calculations. Interestingly, despite the fact that C 20 - T carbon has a porous structure with large cavities, our calculations identify its superhard properties with the Vickers hardness of 72.76 Gpa. The ideal tensile and shear strength of C 20 - T carbon are calculated to be 71.1 and 55.2 GPa respectively, comparable to that of c-BN. Electronic band calculations reveal that this new carbon allotrope is a transparent insulator with an indirect band gap of 5.44 eV. These results broaden our understanding of superhard carbon allotropes.

H18 Carbon: A New Metallic Phase with sp2-sp3 Hybridized Bonding Network.

Design and synthesis of three-dimensional metallic carbons are currently one of the hot issues in contemporary condensed matter physics because of their fascinating properties. Here, based on first-principles calculations, we discover a novel stable metallic carbon allotrope (termed H18 carbon) in () symmetry with a mixed sp(2)-sp(3) hybridized bonding network. The dynamical stability of H18 carbon is verified by phonon mode analysis and molecular dynamics simulations, and its mechanical stability is analyzed by elastic constants, bulk modulus, and shear modulus. By simulating the x-ray diffraction patterns, we propose that H18 carbon would be one of the unidentified carbon phases observed in recent detonation experiments. The analysis of the band structure and density of states reveal that this new carbon phase has a metallic feature mainly due to the C atoms with sp(2) hybridization. This novel 3D metallic carbon phase is anticipated to be useful for practical applications such as electronic and mechanical devices.

[Analyses on the characteristics and the trends of pneumoconiosis notified between 2001 and 2012 in Hebei Province].

OBJECTIVE: To describe the incidence, development and death of pneumoconiosis reported in Hebei from 2001 to 2012 and investigate the epidemiological trends and characteristics of pneumoconiosis to provide basic data for formulating the guidelines and policies for control of pneumoconiosis. METHODS: The Hebei database of new cases of pneumoconiosis reposed from 2001 to 2012 were subjected to systematic arrangement. Clean data and descriptive analysis using SPSS 17.0. The statistical indices included number of new and death pneumoconiosis cases in each year. RESULTS: From 2001 to 2012 a total of 4558 new cases of pneumoconiosis were reported. The situation was same to coal-workers' pneumoconiosis and silicosis. (2) The pneumoconiosis cases were distributed mainly in the city of Tang Shan, Cheng De, Zhang Jia Kou and Han Dan (88.24%). (3) Most cases were centerred in coal industry, metallurgical industry, nonferrous metals industry, architectural material industry and light industry. (4) The mean age of onset in new cases was shorted each year for silicosis, coal-workers' pneumoconiosis, potter pneumoconiosis and electric welder pneumoconiosis, especially for 2010 to 2012 (9 years). (5) The work types of these cases mainly included drilling (26.72%), mining as the main work (6.67%), hybrid coal mine work (6.95%), molding worker (5.24%) and berterring worker (4.82%). (6) The new cases of pneumoconiosis reposed from 2001 to 2012 were diagnosissed I (3415, 74.92%), II (782, 17.16%), III (361, 7.92%). (7) The death cases of pneumoconiosis reposed from 2001 to 2012 were 1182, most of them were distributed mainly in the city of Tang Shan, Cheng De, Zhang Jia Kou and Han Dan (88.24%). CONCLUSION: The incidence of pneumoconiosis is still high: the new cases of pneumoconiosis is still rising. The mean age of onset in new cases was shorted each year. The new cases of pneumoconiosis reposed from 2001 to 2012 were diagnosed II was above 25%. The prevention and control of pneumoconiosis should be enhanced in key industries and for people engaging in key regions, industries, types of work according to the epidemiological characteristics of pneumoconiosis. Most cases were centerred in coal-workers' pneumoconiosis and silicosis.

[Distribution of manganese, cobalt and molybdenum in blood and urine among general population in 8 provinces of China].

OBJECTIVE: To evaluated the manganese (Mn), cobalt (Co) and molybdenum (Mo) levels in blood and urine among general population in China, and thereby to analyze their prevalent features. METHODS: From 2009 to 2010, a total of 18 120 subjects of general population aged 6-60 years were recruited from 24 districts in 8 provinces in eastern, central and western China mainland, by cluster random sampling method. The information about their living environment and health status were collected by questionnaire, and their blood and urine samples were also collected.Inductive coupled plasma mass spectrometry (ICP-MS) was applied to test the Mn, Co and Mo levels of blood and urine samples, and the Mn, Co, Mo distribution in blood and urine among groups of population in different ages and genders were then analyzed. RESULTS: Among general population in China, the geometric mean (GM) of Mn concentration in blood was 8.98 µg/L. The Mn concentration in blood among males and females were separately 8.14 µg/L and 9.88 µg/L (Z = -18.84, P < 0.01). The GM of Mn concentration in urine was 0.63 µg/L. The Mn concentration in urine among males and females were separately 0.62 µg/L and 0.63 µg/L (Z = -0.67, P > 0.05). The geometric mean (GM) of Co concentration in blood was 0.194 µg/L. The Co concentration in blood among males and females were separately 0.166 µg/L and 0.225 µg/L (Z = -23.04, P < 0.01). The GM of Co concentration in urine was 0.282 µg/L. The Co concentration in urine among males and females were separately 0.260 µg/L and 0.307 µg/L (Z = -7.35, P < 0.01). The GM of Mo concentration in blood was 0.25 µg/L. The Mo concentration in blood among male and female group were separately 0.27 µg/L and 0.23 µg/L (Z = -5.03, P < 0.01). The GM of Mo concentration in urine was 27.7 µg/L. The Mo concentration in urine among males and females were 29.8 µg/L and 25.6 µg/L (Z = -6.31, P < 0.01), respectively. CONCLUSION: The Mn, Co and Mo levels in blood and urine varied by gender and area among general population in China, the study provided basic data evidence for the following Mn, Co and Mo biological monitoring studies in near future.

[Study of distribution and influencing factors of lead and cadmium in whole blood and urine among population in 8 provinces in China].

OBJECTIVE: To evaluate the levels of lead (Pb) and cadmium (Cd) in blood and urine among general population in China, and thereby analyze their prevalent features. METHODS: A total of 18 120 subjects from general population aged 6-60 years were recruited from 24 districts in 8 provinces in eastern, central and western China mainland from 2009 to 2010, by cluster random sampling method. The blood samples and urine samples of these people were collected. The questionnaire survey was used to collect the information of the living environment and health conditions.Inductive coupled plasma mass spectrometry was applied to test the Pb and Cd levels in the samples, and the distribution of Pb and Cd in blood and urine for different ages, genders, areas and life habits were then analyzed. RESULTS: Among the general population in China, the geometric mean (GM) of blood Pb concentration was 34.9 µg/L; the GM of blood Pb in male and female groups were 40.1 and 30.4 µg/L (Z = -28.05, P < 0.05), respectively; the GM from eastern, central and western China were 31.2, 38.8 and 58.9 µg/L (χ(2) = 1 483.33, P < 0.05) , respectively. The GM of urine Pb of the whole population was 1.05 µg/L;while the GM in male and female groups were 1.06 µg/L and 1.05 µg/L (Z = -0.73, P > 0.05) , respectively;the values from eastern, central and western China were 0.76, 2.85 and 3.22 µg/L (χ(2) = 1 982.11, P < 0.05), respectively. The GM of blood Cd concentration among general population was 0.49 µg/L; and the values in male and female group were 0.60 and 0.41 µg/L (Z = -11.79, P < 0.05) , respectively; the GM from eastern, central and western China were 0.45, 0.65 and 0.67 µg/L (χ(2) = 69.87, P < 0.05), respectively; the GM of urine Cd concentration of the whole population was 0.28 µg/L, while the GM in male and female groups were 0.29 and 0.28 µg/L (Z = -3.86, P < 0.05), respectively; the values from eastern, central and western China were 0.29,0.42 and 0.18 µg/L (χ(2) = 402.76, P < 0.05), respectively. the Spearman's rank correlation coefficient for Cd in blood and Cd in urine was 0.22, for Pb in blood and Pb in urine was 0.21. Both the correlations were statistic significant (P < 0.05). CONCLUSION: The Pb and Cd levels in blood and urine were relatively higher among general population in China varying by gender and area. There were positive correlations between Pb and Cd levels in blood and those in urine.

[Study of distribution and influencing factors of arsenic in whole blood and urine among population in 8 provinces in China].

OBJECTIVE: To evaluated the levels of arsenic (As) in blood and urine among general population in China and analyze its influencing factors. METHODS: A total of 18 120 subjects from general population aged 6-60 years were recruited from 24 districts in 8 provinces in eastern, central and western China mainland from 2009 to 2010, by cluster random sampling method. Blood samples and urine samples were collected, the information of the life-style was collected by questionnaire.Inductive coupled plasma mass spectrometry was applied to test the As level in the samples, and the distribution of As in blood and urine for different ages, genders, areas and life habits were then analyzed. RESULTS: The geometric mean (GM) of blood As concentration among general population was 2.33 µg/L;the GM of blood As in male (2.35 µg/L) was higher than and female (2.30 µg/L) (Z = -1.42, P < 0.05); from eastern, central to western China, the blood As level were 2.94, 1.30 and 0.98 µg/L (χ(2) = 643.22, P < 0.05) , respectively; the GM in smokers (2.84 µg/L) was higher than non-smokers (2.27) (Z = -6.28, P < 0.05) ;the seafood consumer had a higher blood As level (2.59 µg/L) than people not consuming seafood (1.47 µg/L) (Z = -23.68, P < 0.05). The urine As level of the whole population was 13.72 µg/L;while its GM in male (14.10 µg/L) was higher than female (13.33 µg/L) (Z = -3.94, P < 0.05); the values from eastern, central to western China were 14.14, 16.02 and 9.57 µg/L (χ(2) = 353.89, P < 0.05), respectively;the level in smokers (16.06 µg/L) was higher than nonsmokers (13.70 µg/L) (Z = -2.63, P < 0.05); the level in seafood consumers (14.82 µg/L) was higher than people not consuming seafood (10.99 µg/L) (Z = -3.20, P < 0.05). The blood As level had a positive correlation with urine As level (correlation coefficient:0.285, P < 0.05). CONCLUSION: The As level in blood and urine varied by gender and area among general population in China, and related to life-styles. There was a positive correlation between As level in blood and that in urine.

[Polycyclic aromatic hydrocarbons monohydroxy metabolites level in urine of general population in eight provinces of China].

OBJECTIVE: To assess the levels of polycyclic aromatic hydrocarbons monohydroxy metabolites in urine of general population in China among 8 provinces, provide the baseline of the metabolites in the general population. METHODS: From 2009 to 2010, 18 120 subjects of general population aged 6-60 years old were recruited from 24 areas among 8 provinces in east, west and central areas of China mainland by cluster random sampling. The information of the living environment and health condition were collected by questionnaire and spot urine samples were collected, 4 680 urine samples were analysed by high performance liquid chromatography with tandem mass spectrometry, and monohydroxy metabolites distribution in urine among groups of gender and ages were analysed. RESULTS: Geometric means (GM) of 2-naphthol, 1-naphthol, 3-phenanthrol and 1-hydroxypyrene concentration in urine (95%CI) were 1.85 (1.75-1.95), 1.55 (1.50-1.61), 0.57 (0.54-0.59) and 0.82 (0.78-0.85) µg/L, respectively;and median are 2.44, <0.50, 0.72 and 0.90 µg/L, respectively. The concentration between male and female were significantly different (P < 0.01), and the concentration among the groups of population were significantly different (P < 0.01), the GM of 2-naphthol among the groups of population aged 6-12, 13-16, 17-20, 21-30, 31-45 and 46-60 years old were 1.60, 1.56, 1.69, 2.23, 1.91 and 1.86 µg/L (χ(2) = 17.90, P < 0.01), the GM of 1-naphthol in the groups were 1.30, 1.16, 1.53, 1.68, 1.80 and 1.52 µg/L (χ(2) = 76.22, P < 0.01), the GM of 3-phenanthrol in the groups were 0.78, 0.76, 0.55, 0.42, 0.50 and 0.99 µg/L (χ(2) = 66.48, P < 0.01), the GM of 1-hydroxypyrene in the groups were 0.77,0.64, 1.00, 0.84, 0.84 and 0.57 µg/L (χ(2) = 51.48, P < 0.01), respectively. CONCLUSION: The distribution of monohydroxy metabolites levels in urine of general population were different, it provided a basic data for the further study of polycyclic aromatic hydrocarbons biomonitoring in the population.

[Distribution of copper and zinc in blood among general population from 8 provinces in China].

OBJECTIVE: To investigate the level of zinc (Zn) and copper (Cu) in whole blood among general population from 8 provinces in China, and to analyze the characteristics of distribution among different regions. METHODS: This cross-sectional study was performed in 8 provinces from eastern, middle and western China between 2009 and 2010, including 13 110 subjects from 24 regions, and the blood and urine samples were collected. The ICP-MS was applied to test the content of ICP-MS in blood samples, and the results were used to analyze the characteristics of contents and distributions of Zn and Cu among population from different ages, genders and regions groups. RESULTS: Totally, the mean (95%CI) contents of Cu and Zn in blood were 795 (791-799)µg/L and 3 996(3 976-4 015) µg/L, respectively. The characteristics of distribution of Cu content were as followed, the content of males were lower than it of females (male:767 µg/L; female: 822 µg/L, t = -13.302, P < 0.01). The contents of blood Cu in groups of people aging 6-12, 13-16, 17-20, 21-30, 31-45 and 46-60 years old were separately 860(853-868), 758(748-769), 734(728-734), 782(774-790), 811(795-827) and 820(815-826) µg/L. The differences showed statistical significance (F = 78.77, P < 0.01). The blood Cu content of people in eastern China (800µg/L) were also significantly higher than it in middle (774 µg/L)and western China (782 µg/L) (F = 10.94, P < 0.01). Distribution of blood Zn content showed characteristics as follows: the Zn content was higher in males than in females (male 4 085 µg/L and female 3 908 µg/L, t = 8.78, P < 0.01). The contents of blood Zn in groups of people aging 6-12, 13-16, 17-20, 21-30, 31-45 and 46-60 years old were separately 3 306 (3 261-3 350), 3 888 (3 839-3 937), 3 948 (3 902-3 994), 4 272(4 228-4 315), 4 231(4 180-4 281) and 4 250 (4 205-4 294)µg/L, which showed significant statistical differences (F = 233.68, P < 0.01). The blood Zn content of people in eastern China (3 938 µg/L) were significantly lower than it in middle (4 237 µg/L)and western China (4 105 µg/L) (F = 53.16, P < 0.01). In addition, the study also compared the relation between content of Cu and Zn and the frequency of eating seafood. The results found that the frequency of eating seafood could influence the content of Cu and Zn (Cu: F = 13.54, P < 0.01; Zn: F = 200.20, P < 0.01). CONCLUSION: The contents and distributions of Cu and Zn in blood differs among people from different groups in ages, genders and regions. The baseline data of this study provided reliable scientific evidence for further research.

[Distribution of chromium in whole blood and urine among general population in China between year 2009 and 2010].

OBJECTIVE: To evaluate the chromium (Cr) levels in blood and urine among general population in China between 2009 and 2010, and thereby to analyze its prevalent features. METHODS: From year 2009 to 2010, a total of 11 983 subjects of general population aged between 6 and 60 year-old were recruited from 24 districts in 8 provinces in eastern, central and western China mainland, by cluster random sampling method. The information about their living environment and health status were collected by questionnaire, and 11 983 blood samples and 11 853 urine samples were also collected. Inductively coupled plasma mass spectrometry (ICP-MS) was applied to test the Cr level both in blood and urine; and the Cr distribution in blood and urine among groups of population in different ages, genders and districts, were then analyzed. RESULTS: Among general population in China, the geometric mean (GM) of Cr concentration in blood was 1.19 µg/L, with median at 1.74 µg /L and 95% percentile at 5.59 µg/L. The Cr concentration in blood among males and females were separately 1.18 µg/L and 1.20 µg/L(P > 0.05); while its GM in the groups of population aged 6 - 12, 12 - 16, 16 - 20, 20 - 30, 30 - 45 and 45 - 60 years old were 1.00, 1.22, 1.01, 1.40, 1.27 and 1.30 µg/L (P < 0.01), respectively; and the figures in populations from eastern, central and western China were 1.00, 1.70 and 1.98 µg/L (P < 0.01), respectively. Among general population, the GM of Cr concentration in urine was 0.53 µg/L, with median was lower than 0.42 µg/L and 95% percentile at 3.53 µg/L. The Cr concentration in urine among males and females were separately 0.52 µg/L and 0.53 µg/L (P > 0.05);while its GM in the groups of population aged 6 - 12, 12 - 16, 16 - 20, 20 - 30, 30 - 45 and 45 - 60 years old were 0.56, 0.60, 0.52, 0.50, 0.52 and 0.46 µg/L (P < 0.01), respectively;and the figures in populations from eastern, central and western China were 0.58, < 0.42 and 0.60 µg/L (P < 0.01), respectively. CONCLUSION: The study reported the Cr levels in blood and urine among general population in China, and thereby provided basic data evidence for the following Cr biological monitoring studies in near future.