Determination of trace perchlorate in river water by ion chromatography with online matrix removal and sample concentration.

This paper proposes a simple ion chromatographic approach to determine trace amounts of perchlorate in river water samples. Determination of the trace perchlorate by ion chromatography typically faces two challenges: interference by matrix ions such as chloride, nitrate, and sulfate in the samples and insufficient detection sensitivity. In the present study, online pretreatment of the samples with an OnGuard II Ba/Ag/H disposable sample pretreatment cartridge prevented the sulfate peak tailing from overlapping with the perchlorate peak on the chromatogram. In addition, the matrix removal enabled as large as 10 mL of sample to be loaded into a high exchange capacity anion concentrator, significantly improving perchlorate's detection sensitivity. The proposed approach achieved a detection limit (S/N = 3) of 0.046 µg L-1 without using a costly mass spectrometer and successfully determined sub µg L-1 levels of perchlorate in river water.

Investigation of the concentration ratios of anthropogenic metal elements in fresh snow at mountain area as a tracer for the discrimination between short- and long-range transport contributions.

Atmospheric deposition of anthropogenic aerosols, which is concerned about several targets of SDGs, was investigated in Japan. Concentrations of trace metal elements (V, Ni, Cd, and Pb), which are index of source for fossil fuel combustion, in winter wet deposition (fresh snow) in mountain area were determined. Average concentrations of snow samples were 0.338 ± 0.289 µg L-1 for V, 0.409 ± 0.724 µg L-1 for Ni, 0.109 ± 0.110 µg L-1 for Cd, and 1.77 ± 1.81 µg L-1 for Pb µg L-1. No significant correlations between V and Ni were found for snow samples at remote mountains. A significant correlation between Cd and Pb was observed when the back trajectories of air mass deriving snowfall passed through Northeast China and Huabei. Significant correlations between V and Pb were found in mountains when the air mass passed through Northeast China and Huabei. Changes in normalized concentrations of trace metal elements in snow at the same snowfall event indicated contributions from short-range transportation in suburb area. The metal element concentration ratios were shown to be useful tracers for discrimination between short- and long-range contributions of anthropogenic elements in snow.

Determination of Trace Elements in Aerosols at a Rural Mountainous Area and a Local City of Eastern Shikoku Region, Japan.

A simple digestion method for a mixed cellulose membrane filter in order to analyze trace elements in aerosols was examined. The determination of Cu, Fe and Ni in the certified reference materials of China loess (CJ-1) could be conducted using the digestion method. Trace elements in aerosols smaller than 10 µm size collected at Tokushima City and near mountain areas for each season were determined as a water-soluble fraction and all components by the digestion method. Back trajectory analysis implied that the contribution from the Asian continent was larger in the winter and spring than the summer. Systematic changes in the trace element compositions for each season were not observed, except for Fe, Th and U. Water-soluble components in aerosols at Tokushima City showed higher concentrations of all trace elements than those of the mountain areas. For aerosols in Tokushima City and near to the mountain areas, As, Bi, Cd, Cu and Pb were mainly derived from anthropogenic sources, whereas Ba, Co, Cs, Ga, Mn, Rb, Sr, Th, U and V were derived from natural crustal sources. The origin of Pb and Cd was considered based on the Pb/Cd ratio.

Relationships Between Cortically Mediated Attentional Dysfunction and Social Anxiety, Self-Focused Attention, and External Attention Bias.

Social anxiety disorder is characterized by a marked fear and avoidance of social situations or a fear of being evaluated by others. Although training for top-down attentional control has been an effective treatment for social anxiety disorder, few studies have demonstrated that individuals with social anxiety have top-down attentional dysfunction. This study used dichotic listening (DL) tasks to investigate the relationship between social anxiety and top-down attentional control over relevant brain activities. We also investigated relationships between both social situation-dependent self-focused attention and external attention bias and situation-independent attentional control. Thirty-six healthy participants underwent near-infrared spectroscopy scanning while performing top-down selective and divided attention DL tasks. Then, they undertook a speech task and completed a questionnaire to assess the degrees of their self-focused attention and external attention bias. The results showed that the degree of social fear and self-focused attention during the speech task were negatively correlated with scores on the selective attention task and with the activity of the left pars opercularis during the selective DL task, which were related to each other. These results suggest that a relationship exists between social fear, self-focused attention in a social situation, and top-down selective attentional dysfunction as assessed both behaviorally and by brain activity changes.

Sulfur Chemical State and Chemical Composition of Insoluble Substance in Soft Rime, Hard Rime, and Snow Collected in Remote and Rural Areas in Japan Using Wavelength-dispersive X-ray Fluorescence.

Using a commercially available wavelength-dispersive X-ray fluorescence (WDXRF) spectrometer, the chemical composition and S-Kα spectrum of rime and snow samples collected in remote and rural areas of Japan were measured with a membrane filter sample technique to investigate the long-range transport of aerosol from the East Asian continent. Insoluble substances are derived into three categories: 1) conventional mineral origin (crustal substance), 2) urban dust origin (Fe-Zn-Ca) and 3) coal origin (S-As). Assuming that (i) S(VI) was found as a plaster-like substance in hard rime, depending on [Ca], and that (ii) S(-II) was found as non-crustal sulfur compounds, fractions of S(VI) and S(-II) in rime could be calculated as 35 ± 6 and 66 ± 7% by [Ca], which is in agreement with 32 ± 8 and 68 ± 8%, respectively, by the chemical shift of the S-Kα line. During a one-day meteorological event that included the accumulation of both rime and snow, differences to the snow-like content corresponded to characteristics typical of rime since the chemical compositions of rime also includes the composition of the snow. The fractions of 22 ± 12% of S(VI) and 76 ± 12% of S(-II), respectively, were found in rime. The fraction of S(-II) decreased from the Chugoku district towards the Shikoku district. Along the coast of the Japan Sea, the fraction of S(-II) decreased from Chugoku district toward the Northeast Japan. It can be proposed that other analytical techniques of S, Al, and Ca in that are favorable to this fractionation.

Cellular adverse actions of dibromoacetonitrile, a by-product in water bacterial control, at sublethal levels in rat thymocytes.

The aim of this study was to investigate the effects of dibromoacetonitrile (DBAN), a by-product in water bacterial control, at sublethal concentrations on rat thymocytes, by using a cytometric technique with appropriate fluorescent dyes. By using this method, the possibility that DBAN induces cellular actions related to oxidative stress was assessed. DBAN reduced the content of cellular nonprotein thiols under Zn2+-free conditions. It elevated the intracellular level of Zn2+, being independent from external Zn2+. DBAN increased cell vulnerability to the cytotoxic action of hydrogen peroxide. These actions of DBAN were likely related to oxidative stress. DBAN is formed by the reaction of bromides and chlorinated oxidants during water disinfection. Hydrolysis of 2,2-dibromo-3-nitrilopropionamide, an antimicrobial used in hydraulic fracturing fluids for production of shale gas and oil, produces DBAN. Therefore, the concern regarding the levels of DBAN in industrial water systems is necessary to avoid the environmental risk to humans and wild mammals.

Corneal Erosion With Pigments Derived From a Cosmetic Contact Lens: A Case Report.

PURPOSE: To report a case of corneal erosion with pigments derived from a cosmetic contact lens (CCL). METHODS: A 29-year-old woman complained of foreign body sensation after wearing CCL. Slit-lamp examination of her left eye revealed corneal erosion with yellow pigment at its edges. The surface of the CCLs was examined using the rub-off test and scanning electron microscopy (SEM). An elementary analysis using SEM with energy-dispersive x-ray (SEM-EDX) was also performed. RESULTS: On the back surface of the CCL, the pigments easily came off during the rub-off test. An SEM examination found exposed pigments with needle-like construction on the back surface. SEM-EDX revealed the presence of carbon, oxygen, iron, titanium, and chlorine in the pigments. CONCLUSION: Direct contact between the bare pigments on a CCL and the corneal surface can cause corneal damage.

Use of Multichannel Near Infrared Spectroscopy to Study Relationships Between Brain Regions and Neurocognitive Tasks of Selective/Divided Attention and 2-Back Working Memory.

While dichotic listening (DL) was originally intended to measure bottom-up selective attention, it has also become a tool for measuring top-down selective attention. This study investigated the brain regions related to top-down selective and divided attention DL tasks and a 2-back task using alphanumeric and Japanese numeric sounds. Thirty-six healthy participants underwent near-infrared spectroscopy scanning while performing a top-down selective attentional DL task, a top-down divided attentional DL task, and a 2-back task. Pearson's correlations were calculated to show relationships between oxy-Hb concentration in each brain region and the score of each cognitive task. Different brain regions were activated during the DL and 2-back tasks. Brain regions activated in the top-down selective attention DL task were the left inferior prefrontal gyrus and left pars opercularis. The left temporopolar area was activated in the top-down divided attention DL task, and the left frontopolar area and left dorsolateral prefrontal cortex were activated in the 2-back task. As further evidence for the finding that each task measured different cognitive and brain area functions, neither the percentages of correct answers for the three tasks nor the response times for the selective attentional task and the divided attentional task were correlated to one another. Thus, the DL and 2-back tasks used in this study can assess multiple areas of cognitive, brain-related dysfunction to explore their relationship to different psychiatric and neurodevelopmental disorders.

Study of the roles of chemical modifiers in determining boron using graphite furnace atomic absorption spectrometry and optimization of the temperature profile during atomization.

The measurement conditions for determining boron using graphite furnace-atomic absorption spectrometry (GF-AAS) were investigated. Differences in the boron absorbance profiles were found using three different commercially available GF-AAS instruments when the graphite atomizers in them were not tuned. The boron absorbances found with and without adjusting the graphite atomizers suggested that achieving an adequate absorbance for the determination of boron requires a sharp temperature profile that overshoots the target temperature during the atomization process. Chemical modifiers that could improve the boron absorbance without the need for using coating agents were tested. Calcium carbonate improved the boron absorbance but did not suppress variability in the peak height. Improvement of boron absorbance was comparatively less using iron nitrate or copper nitrate than using calcium carbonate, but variability in the peak height was clearly suppressed using iron nitrate or copper nitrate. The limit of detection was 0.0026 mg L(-1) when iron nitrate was used. It appears that iron nitrate is a useful new chemical modifier for the quick and simple determination of boron using GF-AAS.

Scanning Electron Microscopy Findings With Energy-Dispersive X-ray Investigations of Cosmetically Tinted Contact Lenses.

OBJECTIVE: To investigate the surfaces and principal elements of the colorants of cosmetically tinted contact lenses (Cos-CLs). METHODS: We analyzed the surfaces and principal elements of the colorants of five commercially available Cos-CLs using scanning electron microscopy with energy-dispersive x-ray analysis. RESULTS: In two Cos-CLs, the anterior and posterior surfaces were smooth, and colorants were found inside the lens. One lens showed colorants located to a depth of 8 to 14 µm from the anterior side of the lens. In the other lens, colorants were found in the most superficial layer on the posterior surface, although a coated layer was observed. The colorants in the other three lenses were deposited on either lens surface. Although a print pattern was uniform in embedded type lenses, uneven patterns were apparent in dot-matrix design lenses. Colorants used in all lenses contained chlorine, iron, and titanium. In the magnified scanning electron microscopy images of a certain lens, chlorine is exuded and spread. CONCLUSIONS: Cosmetically tinted contact lenses have a wide variety of lens surfaces and colorants. Colorants may be deposited on the lens surface and consist of an element that has tissue toxicity.

Yttrium decreases the intracellular Zn2+ concentration in rat thymocytes by attenuating a temperature-sensitive Zn2+ influx.

Yttrium is used in the production of various electronic devices because the alloy it contains enhances or modifies the properties of other elements. In order to study the cytotoxic action of yttrium, the effect of yttrium chloride (YCl(3)) on the intracellular Zn(2+) level was examined in rat thymocytes using a flow cytometer with FluoZin-3-AM and propidium iodide. The application of YCl(3) significantly decreased the intensity of the FluoZin-3 fluorescence, suggesting a decrease in the intracellular Zn(2+) level or quenching of the FluoZin-3 fluorescence by Y(3+). However, since Y(3+) did not attenuate the FluoZin-3 fluorescence under cell-free conditions, the latter suggestion was ruled out. Rat thymocytes possess a temperature-sensitive membrane pathway that carries Zn(2+) into the cells. The application of YCl(3) attenuated the FluoZin-3 fluorescence augmented by externally applied ZnCl(2) in a concentration-dependent manner. This suggested that Y(3+) inhibited the Zn(2+) influx, resulting in the decrease in the intracellular Zn(2+) level. Yttrium may induce dyshomeostasis of intracellular Zn(2+), leading to some cytotoxic actions.

Radical scavenging activity of spring mountain herbs in the Shikoku mountain area and identification of antiradical constituents by simple HPLC detection and LC-MS methods.

The functionality of spring mountain herbs, which were collected in the Kajigamori mountain area of Shikoku area in Japan, was investigated in the course of our studies for utilizing local plant resources. The radical scavenging activity of the extracts from seventeen herbs was measured. Among these herbs, two extracts from Polystichym ovato-paleaceum (Japanese name: Tsuyanashiinode) and Sambucus racemosa subsp. sieboldiana (Japanese name: Niwatoko) showed potent DPPH radical scavenging activity. The material evidence for the potent activity of the extracts was studied by a combination of our developed method for detecting antiradical compounds, LC-MS/MS, and enzymatic hydrolysis.

Evaluation of bony impingement in regard to internal rotation limit after total hip arthroplasty using rotation matrix.

OBJECTIVES: Bony impingement of the proximal femur on the pelvis is an important factor for dislocation after total hip arthroplasty (THA). We evaluated bony impingement after THA using the rotation matrix derived from postoperative computed tomography (CT) images. PATIENTS AND METHODS: One hundred and seven hip joints were subjected to primary THA via a posterolateral approach. We used the rotation matrix derived from CT images to calculate internal rotation (IR) limit prior to bony impingement, and compared this limit with the intraoperative limit. RESULTS: The average calculated IR limit was 63 degrees (range: 30 to 85 degrees). The average intraoperative IR limit was 49 degrees (range: 20 to 70 degrees). The correlation between the intraoperative IR limit (Y) and the calculated IR limit (X) was expressed as Y=8.9+0.66X (R=0.73; p < 0.0001). CONCLUSIONS: We could show a patient's safe range of motion prior to bony impingement, and this will be a good indicator for dislocation not occurring during postoperative rehabilitation.

Some characteristics of membrane Cd²+ transport in rat thymocytes: an analysis using Fluo-3.

Although cadmium-induced apoptosis of lymphocytes is one of common features in the immunotoxicity of cadmium, the membrane pathway for intracellular cadmium accumulation is not fully elucidated. To characterize membrane Cd(2+) transport of rat thymocytes, the change in intracellular Cd(2+) concentration under various conditions was examined by the use of Fluo-3, a fluorescent probe for monitoring the change in intracellular concentration of divalent metal cations. The membrane Cd(2+) transport was estimated by the augmentation of Fluo-3 fluorescence induced by bath application of CdCl(2). Lowering temperature strongly suppressed the augmentation of Fluo-3 fluorescence by CdCl(2), suggesting that the metabolic process can be involved in membrane Cd(2+) transport. External acidification (decreasing pH) and membrane depolarization by adding KCl attenuated the augmentation, indicating the requirement of electrochemical driving force for membrane Cd(2+) transport into the cells. Bath application of CaCl(2) and ZnCl(2) equally decreased the augmentation, suggesting their competition with Cd(2+) at the membrane transport. The augmentation by CdCl(2) was lesser in the cells treated with N-ethylmaleimide inducing chemical depletion of cellular thiols. The result suggests the contribution of sulfhydryl groups to membrane Cd(2+) transport. Taken together, it is suggested that the cells possess a temperature-sensitive membrane Cd(2+) pathway, driven by electrochemical gradient of Cd(2+) and transmembrane potential, with competitive binding site. Based on the characteristics described above, it is unlikely that the membrane Cd(2+) transport in rat thymocytes is attributed to a single transport system although it has characteristics that are similar to those of divalent cation transporter 1.

Zn(2+), derived from cell preparation, partly attenuates Ca(2+)-dependent cell death induced by A23187, calcium ionophore, in rat thymocytes.

A23187, a calcium ionophore, is used to induce Ca(2+)-dependent cell death by increasing intracellular Ca(2+) concentration ([Ca(2+)](i)) under in vitro condition. Since this ionophore also increases membrane permeability of metal divalent cations such as Zn(2+) and Fe(2+) rather than Ca(2+), trace metal cations in cell suspension may affect Ca(2+)-dependent cell death induced by A23187. Therefore, the effects of chelators for divalent metal cations, EDTA and TPEN, on the A23187-induced cytotoxicity were cytometrically examined in rat thymocytes. The cytotoxicity of A23187 was attenuated by 1mM EDTA while it was augmented by 50 microM EDTA and 10 microM TPEN. These changes were statistically significant. The A23187-induced increase in Fluo-3 fluorescence intensity, a parameter for [Ca(2+)](i), was significantly reduced by 1mM EDTA while it was not the case for 50 microM EDTA and 10 microM TPEN. The intensity of FluoZin-3 fluorescence, a parameter for [Zn(2+)](i), increased by A23187 was respectively reduced by 50 microM EDTA and 10 microM TPEN. It is suggested that the attenuation of A23187-induced cytotoxicity by 1mM EDTA is due to the chelation of extracellular Ca(2+) and Zn(2+) while the augmentation by 50 microM ETDA or 10 microM TPEN is due to the chelation of extracellular Zn(2+). The Tyrode's solution without thymocytes contained 32.4 nM of zinc while it was 216.9 nM in the cell suspension. In conclusion, trace Zn(2+), derived from cell preparation, partly attenuates the Ca(2+)-dependent cell death induced by A23187.

Beneficial effects of Ajuga decumbens on osteoporosis and arthritis.

Extract of the whole plant, Ajuga decumbens (KE) has long been used in China as a medication for the relief of joint pain. Previously, we proved that KE up-regulated the synthesis of collagen in false aged model rats. In this paper we examined the effects of KE on nitric oxide (NO) production, expression of inducible nitric oxide synthase (iNOS), osteoblast and osteoclast activity. We also investigated whether KE had any anti-osteoporosis or anti-arthritic activity by using ovariectmized mice and adjuvant induced arthritic rats. KE exhibited down-regulation of differentiation into osteoclast and up-regulation of mineralization in osteoblast-like MC3T3-E1 cells in a concentration-dependent manner. NO synthesized by iNOS plays important roles in inflammatory disease and imbalance between bone resorption and bone formation caused by estrogen depletion. KE inhibited expression of iNOS which caused concentration dependent inhibition of NO production. Furthermore, KE prevented brittle bones in ovariectomized mice and swelling of the left hind ankle in adjuvant induced arthritic rats. Therefore, KE improved the balance of bone resorption and bone formation, showing anti-inflammatory effects. Consequently, KE is beneficial for sufferers of bone and joint disease.

Anti-obesity effect of Nelumbo nucifera leaves extract in mice and rats.

The leaf of Nelumbo nucifera Gaertn. (family Nymphaeaceae) has been used for summer heat syndrome as home remedy in Japan and China, and it has recently been used to treat obesity in China. So we investigate the pharmacological mechanism of the anti-obesity effect of Nelumbo nucifera leaves extract (NNE). We examined the effect of NNE on digestive enzyme activity, lipid metabolism and theromogenesis and evaluated the effects of anti-obesity using high-fat diet-induced obesity in mice that were treated with NNE for 5 weeks. NNE caused a concentration-dependent inhibition of the activities of alpha-amylase and lipase, and up-regulated lipid metabolism and expression of UCP3 mRNA in C2C12 myotubes. NNE prevented the increase in body weight, parametrial adipose tissue weight and liver triacylglycerol levels in mice with obesity induced by a high-fat diet. UCP3 mRNA expression in skeletal muscle tended to be higher, when mice were administrated by NNE and were exercised. Therefore, NNE impaired digestion, inhibited absorption of lipids and carbohydrates, accelerated lipid metabolism and up-regulated energy expenditure. Consequently, NNE is beneficial for the suppression of obesity.

Large-volume injection electrothermal AAS combined with tungsten-treated pyrolytic graphite furnace: determination of cadmium in tap, snow and river water samples with phosphate modifier.

A large-volume (100 microl) injection-ETAAS with W-treated PG furnace combined with a phosphate modifier was applied to the determination of unpolluted levels of Cd in tap, snow and river-water samples. The limit of detection of 1.1 ng l(-1) was observed for a 4 w/v% NH4H2PO4 modifer. Matrix interference studies were tested for major ion species well found in fresh water. The direct determination of Cd in certified river water (12 +/- 2 ng l(-1)) was carried out and the observed value was in agreement with the certified one. The good recoveries of Cd added to real environmental water samples were also observed. This method was applied to the determination of Cd in unpolluted environmental water samples.

Pyrolytic and non-pyrolytic boron nitride platforms in electrothermal AAS for the determination of cadmium in sea and estuarine water without chemical modification.

The analytical performance of pyrolytic and non-pyrolytic boron nitride (PBN and NBN) platforms, attached to a commercially available graphite tube furnace, in electrothermal atomic absorption spectrometry (ETAAS) for Cd was studied. Although the tolerable pyrolysis temperature was 300 degrees C with the conventional pyrolytic graphite platform, it increased to 600 and 950 degrees C with the PBN and NBN platforms, respectively. The lifetime of the ceramic platform was 500 firings. The NBN platform provided an enhanced sensitivity with a better reproducibility than others. Using the NBN platform allowed the LOD, based on the variability of the blank (3sigma), to be 0.1 microg l(-1) within a seawater matrix (20,000 mg NaCl l(-1)) and a constant sensitivity in the range 0-30,000 mg NaCl l(-1). Good recovery in the range of 90-105% was observed for Cd (2.0 microg l(-1)) spiked into sea, estuarine and river water samples using the recommended procedure. This work proposes that using the NBN platform allows the direct monitoring and control of contaminated water for Cd by ETAAS without any chemical modification.