Association of exposure to multiple metals with hemoglobin levels in Chinese children and adolescents.

BACKGROUND: Previous studies have linked single metal to hemoglobin levels in children and adolescents; however, studies with regards to metal mixtures are still limited. OBJECTIVE: We aimed to investigate the associations of single metal and metal mixtures with hemoglobin levels in children and adolescents. METHODS: We conducted a cross-sectional study of 2064 children and adolescents aged 6 to 19 years in Liuzhou, China in 2018. The concentrations of 15 metals in urine were determined by inductively coupled plasma mass spectrometry. Generalized linear regression and weighted quantile sum (WQS) regression were used to estimate the associations of single metal and metal mixtures with hemoglobin levels, respectively. RESULTS: The multivariable-adjusted ß-values for the highest versus the first quartiles of urinary metal concentrations were - 1.57 (95 % confidence interval [CI]: -3.01, -0.13) for chromium, -2.47 (95 % CI: -3.90, -1.05) for nickel and 1.88 (95 % CI: 0.49, 3.28) for copper. In addition, we found a significant negative association between the WQS index and hemoglobin levels (adjusted ß = -0.93, 95 % CI: -1.69, -0.19), with nickel contributing the most to the WQS index at 59.0 %. Subgroup analyses showed that exposure to urinary nickel or metal mixtures were associated with decreased hemoglobin levels in adolescents, but not in children (all Pinteration < 0.001). CONCLUSION: Among children and adolescents, urinary chromium and nickel concentrations were associated with decreased hemoglobin levels, while copper showed a positive relationship. Moreover, a negative association was observed between exposure to metal mixtures and hemoglobin levels. These findings need to be further validated in prospective studies.

High-Magnetization Tetragonal Ferrite-Based Films Induced by Carbon and Oxygen Vacancy Pairs.

Herein, a low-temperature thermal decomposition method is utilized to grow new stable tetragonal Fe3O4-based thick ferrite films. The tetragonal Fe3O4-based film possesses high saturation magnetization of ∼800 emu/cm3. Doping with approximately 10% Co results in a high-energy product of ∼10.9 MGOe with perpendicular magnetocrystalline anisotropy, whereas doping with Ni increases electrical resistivity by a factor of 6 and retains excellent soft magnetic properties (high saturation magnetization and low coercivity). A combined experimental and first-principles study reveals that carbon interstitials (CiB) and oxygen vacancies (VO) form CiB-VO pairs which stabilize the tetragonal phase and enhance saturation magnetization. The magnetization enhancement is further attributed to local ferromagnetic coupling between FeA and FeB induced by CiB-VO pairs in a tetragonal spinel ferrite lattice.

Passively Q-switched Yb-doped dual-wavelength fiber laser based on a gold-nanocage saturable absorber.

In this paper, we demonstrate a passively Q-switched Yb-doped dual-wavelength fiber laser using gold nanocages (GNCs) as a saturable absorber. The GNCs are prepared by the seed-mediated method with modulation depth of 5.3% and saturable intensity of 0.16 MW/cm2. A simultaneous dual-wavelength operation is achieved at 1059.9 and 1060.5 nm with 3 dB bandwidths of 0.05 and 0.04 nm, respectively. A maximum average output power of 6.03 mW with minimum pulse width of 2.06 µs and maximum repetition rate of 134.9 kHz is obtained at a pump power of 385 mW, corresponding to optical-to-optical conversion efficiency of 1.57% and slope efficiency of 2.75%.

A coiled-coil- and C2-domain-containing protein is required for FAZ assembly and cell morphology in Trypanosoma brucei.

Trypanosoma brucei, a flagellated protozoan parasite causing human sleeping sickness, relies on a subpellicular microtubule array for maintenance of cell morphology. The flagellum is attached to the cell body through a poorly understood flagellum attachment zone (FAZ), and regulates cell morphogenesis using an unknown mechanism. Here we identified a new FAZ component, CC2D, which contains coiled-coil motifs followed by a C-terminal C2 domain. T. brucei CC2D is present on the FAZ filament, FAZ-juxtaposed ER membrane and the basal bodies. Depletion of CC2D inhibits the assembly of a new FAZ filament, forming a FAZ stub with a relatively fixed size at the base of a detached, but otherwise normal, flagellum. Inhibition of new FAZ formation perturbs subpellicular microtubule organization and generates short daughter cells. The cell length shows a strong linear correlation with FAZ length, in both control cells and in cells with inhibited FAZ assembly. Together, our data support a direct function of FAZ assembly in determining new daughter cell length by regulating subpellicular microtubule synthesis.

A comparative proteomic analysis reveals a new bi-lobe protein required for bi-lobe duplication and cell division in Trypanosoma brucei.

A Golgi-associated bi-lobed structure was previously found to be important for Golgi duplication and cell division in Trypanosoma brucei. To further understand its functions, comparative proteomics was performed on extracted flagellar complexes (including the flagellum and flagellum-associated structures such as the basal bodies and the bi-lobe) and purified flagella to identify new bi-lobe proteins. A leucine-rich repeats containing protein, TbLRRP1, was characterized as a new bi-lobe component. The anterior part of the TbLRRP1-labeled bi-lobe is adjacent to the single Golgi apparatus, and the posterior side is tightly associated with the flagellar pocket collar marked by TbBILBO1. Inducible depletion of TbLRRP1 by RNA interference inhibited duplication of the bi-lobe as well as the adjacent Golgi apparatus and flagellar pocket collar. Formation of a new flagellum attachment zone and subsequent cell division were also inhibited, suggesting a central role of bi-lobe in Golgi, flagellar pocket collar and flagellum attachment zone biogenesis.

[Gas pipeline leak detection based on tunable diode laser absorption spectroscopy].

The principle of tunable diode laser absorption spectroscopy and harmonic detection technique was introduced. An experimental device was developed by point sampling through small multi-reflection gas cell. A specific line near 1 653. 7 nm was targeted for methane measurement using a distributed feedback diode laser as tunable light source. The linearity between the intensity of second harmonic signal and the concentration of methane was determined. The background content of methane in air was measured. The results show that gas sensors using tunable diode lasers provide a high sensitivity and high selectivity method for city gas pipeline leak detection.

Growth of single-crystalline Ni and Co nanowires via electrochemical deposition and their magnetic properties.

Single-crystalline Ni nanowires have been successfully fabricated with anodic aluminum oxide as template by electrodeposition. Structural characterization (X-ray diffraction, XRD, and high-resolution transmission electron microscopy, HRTEM) shows that the single-crystalline Ni nanowire has a preferred orientation along the [220] direction. The effects of electrochemical deposition conditions on the structure of Ni nanowires are systematically studied to investigate the growth mechanism. Possible reasons for the growth of the single-crystalline Ni nanowires were discussed on the basis of electrochemistry and thermodynamics. These single-crystalline Ni nanowires have exhibited excellent magnetic properties (large anisotropy, large coercivity, and high remanence). By a similar process, single-crystalline Co nanowires with hexagonal close-packed (hcp) structure were achieved, also having large anisotropy, large coercivity (1.8 kOe), and high remanence ratio (80.8%).