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Recent advances in wearable technology have enabled us to visualize how stroke patients spend time and how they behave during physical activity over a period of 24-h. This capability is expected to provide new insights into rehabilitation research. However, wearable electrocardiograph (ECG) monitoring devices generate noise and artifacts from external factors such as body movements, which causes misdetection of the R wave. To compensate for the loss of heart rate data due to misdetection, the present study focused on ensemble averaging as a method to impute missing data and validated this method of data imputation on 24-h recordings. First, to investigate the measurement period for data imputation, we continuously measured heart rates of six healthy participants for four days and applied ensemble averaging to the first two, three and all four days of measurement data. Next, we validated the imputation by ensemble averaging with 218 measurement data from 63 stroke inpatients in a rehabilitation ward. For the healthy participants, the period with data losses decreased from 115 min (8.3% of the 24-h) to 5.5 min (0.4%), 0 min (0%), and 0 min (0%) when ensemble averaging was applied to two, three, and four days of measurement data, respectively. For data of stroke patients acquired in a two-day measurement session, ensemble averaging decreased the period with data losses more than the conventional method that selects data of the day with the least missing data among the measurement days did (0.17 and versus 1.7% of the 24-h). The median and maximum heart rate when ensemble averaging was applied was strongly correlated to the median and maximum heart rate when ensemble averaging was not applied. The results suggest that ensemble averaging is useful for imputing missing vital data such as heart rate.

Background: Recent advancements in wearable technology has enabled easy measurement of daily activities, which can be applied in rehabilitation practice for the purposes such as maintaining and increasing the activity levels of the patients. A smart clothing system is one of the newly developed wearable systems that enables the measurement of physical activity such as heart rate and/or acceleration. In this study, we aimed to examine the validity of trunk acceleration measurement using a smart clothing system (‘hitoe’ system) in assessing the physical activity, which was measured using the expiratory gas analysis. Methods: Twelve healthy individuals participated in the study. The trunk acceleration was simultaneously measured using a triaxial accelerometer embedded in a smart clothing activity monitoring system (‘hitoe’ system), and the percent VO2 reserve (%VO2R) was determined by performing expiratory gas analysis during treadmill testing. Three parameters, that is, moving average (MA), moving standard deviation (MSD), and moving root mean square (RMS), were calculated using the norm of the trunk acceleration. The relationships between these accelerometer-based parameters and %VO2R from expiratory gas analysis for each individual were examined. Results: The values of MA, MSD, RMS, and %VO2R were significantly different between levels 1, 2, 3, and 4 in the Bruce protocol (P2R vs. MA, %VO2R vs. MSD, and %VO2R vs. RMS were 0.89±0.05, 0.96±0.03 and 0.91±0.05, respectively. The parameters based on the trunk acceleration measurements were significantly correlated with %VO2R and activity levels. Among the parameters examined, MSD showed the best correlation with %VO2R, indicating high validity of the parameter for assessing physical activity. Conclusions: The present results support the validity of the MSD calculated from the trunk acceleration measured with a smart clothing system in assessing the exercise intensity.Trial registration: UMIN000034967Registered 21 November 2018 (retrospectively registered).

Background Recent advancements in wearable technology have enabled easy measurement of daily activities, potentially applicable in rehabilitation practice for various purposes such as maintaining and increasing patients’ activity levels. In this study, we aimed to examine the validity of trunk acceleration measurement using a chest monitor embedded in a smart clothing system (‘hitoe’ system), an emerging wearable system, in assessing the physical activity in an experimental setting with healthy subjects (Study 1) and in a clinical setting with post-stroke patients (Study 2). Methods Study 1 involved the participation of 14 healthy individuals. The trunk acceleration, heart rate (HR), and oxygen consumption were simultaneously measured during treadmill testing with a Bruce protocol. Trunk acceleration and HR were measured using the "hitoe" system, a smart clothing system with embedded chest sensors. Expiratory gas analysis was performed to measure oxygen consumption. Three parameters, moving average (MA), moving standard deviation (MSD), and moving root mean square (RMS), were calculated from the norm of the trunk acceleration. The relationships between these accelerometer-based parameters and oxygen consumption-based physical activity intensity measured with the percent VO2 reserve (%VO2R) were examined. In Study 2, 48 h of simultaneous measurement of trunk acceleration and heart rate-based physical activity intensity in terms of percent heart rate reserve (%HRR) was conducted with the "hitoe" system in 136 post-stroke patients. Results The values of MA, MSD, RMS, and %VO2R were significantly different between levels 1, 2, 3, and 4 in the Bruce protocol (P 2R versus MA, %VO2R versus MSD, and %VO2R versus RMS were 0.89 ± 0.05, 0.96 ± 0.03, and 0.91 ± 0.05, respectively. Among the parameters examined, MSD showed the best correlation with %VO2R, indicating high validity of the parameter for assessing physical activity intensity. The 48-h measurement of MSD and %HRR in post-stroke patients showed significant within-individual correlation (P Conclusions The results support the validity of the MSD calculated from the trunk acceleration measured with a smart clothing system in assessing the physical activity intensity. Trial registration: UMIN000034967. Registered 21 November 2018 (retrospectively registered).

Xylitol separation from a polyol mixture of the byproducts from bioethanol production processes was performed by liquid chromatography using short columns packed with lanthanide ion-loaded ion-exchange resins. Xylitol was successfully separated with sufficiently high resolution using adsorbents with medium rare-earth metal ions, such as Nd3+ and Sm3+. The adsorbents' specific nature is explained by the so-called "gadolinium break," which is known as a discontinuous behavior of thermodynamic parameters in complexation of the lanthanide series. From the observed behavior, the optimum lanthanide ions could be chosen to prepare appropriate adsorbents for ligand-exchange chromatography of given polyol mixtures.

BackgroundThe recent development of wearable devices has enabled easy and continuous measurement of heart rate (HR). Exercise intensity can be calculated from HR with indices such as percent HR reserve (%HRR); however, this requires an accurate measurement of resting HR, which can be time-consuming. The use of HR during sleep may be a substitute that considers the calibration-less measurement of %HRR. This study examined the validity of %HRR on resting HR during sleep in comparison to percent oxygen consumption reserve (%VO2R) as a gold standard. Additionally, a 24/7%HRR measurement using this method is demonstrated.MethodsTwelve healthy adults aged 29 ± 5 years underwent treadmill testing using the Bruce protocol and a 6-min walk test (6MWT). The %VO2R during each test was calculated according to a standard protocol. The %HRR during each exercise test was calculated either from resting HR in a sitting position (%HRRsitting), when lying awake (%HRRlying), or during sleep (%HRRsleeping). Differences between %VO2R and %HRR values were examined using Bland-Altman plots. A 180-day, 24/7%HRR measurement with three healthy adults was also conducted. The %HRR values during working days and holidays were compared.ResultsIn the treadmill testing, the mean difference between %VO2R and %HRRsleepingwas 1.7% (95% confidence interval [CI], − 0.2 to 3.6%). The %HRRsittingand %HRRlyingvalues were 10.8% (95% CI, 8.8 to 12.7%) and 7.7% (95% CI, 5.4 to 9.9%), respectively. In the 6MWT, mean differences between %VO2R and %HRRsitting, %HRRlyingand %HRRsleepingwere 12.7% (95% CI, 10.0 to 15.5%), 7.0% (95% CI, 4.0 to 10.0%) and − 2.9% (95% CI, − 5.0% to − 0.7%), respectively. The 180-day, 24/7%HRR measurement presented significant differences in %HRR patterns between working days and holidays in all three participants.ConclusionsThe results suggest %HRRsleepingis valid in comparison to %VO2R. The results may encourage a calibration-less, 24/7 measurement model of exercise intensity using wearable devices.Trial registrationUMIN000034967.Registered 21 November 2018 (retrospectively registered).

To find commercially available ion exchange resins comparable to a strong-base anion exchange resin Diaion MA03SS, which is specialized for the separation of sulfuric acid and sugars in concentrated sulfuric acid hydrolysates of non-food biomass by means of a simulated moving bed (SMB) chromatography, the screening test of 6 kinds of commercially available resins containing quaternary ammonium groups was carried out by a batch column-mode chromatographic separation of glucose and sulfuric acid at 50 °C. Based on results of the screening test, Dowex 1X4 and Dowex 1X8 were selected as replacements of Diaion MA03SS. The following SMB study using Diaion MA03SS, Dowex 1X4 and Dowex 1X8 at 50 °C clarified that Dowex 1X8 showed performances almost the same as those of Diaion MA03SS in the separations of sulfuric acid and sugars (mainly glucose and xylose) in hydrolysates of bamboo with 27 wt% sulfuric acid under the averaged flow rate of feed loading from 0.136 to 0.273 L/(h L-resin). For Dowex 1X8, recoveries of sulfuric acid were 90.5–93.4% and recoveries of glucose and xylose were 94.9–99.7% and 82.8–88.3%, respectively. Dowex 1X4 showed slightly higher recoveries for three solutes; namely sulfuric acid recoveries were 95.0–95.5% and glucose and xylose recoveries were 100–101% and 86.1–91.7%, respectively. However, the highest averaged flow rate of feed loading for Dowex 1X4 was 0.205 L/(h L-resin) because of the higher column pressure loss owing to its high shrinking in 30 wt% sulfuric acid. Thus, it became clear that Dowex 1X8 exhibit excellent performances comparable to or higher than those of Diaion MA03SS in the SMB chromatographic separation of sulfuric acid and sugars in concentrated sulfuric acid hydrolysate of bamboo.

We systematically evaluated the effects of operating conditions on biofouling behaviors in reverse osmosis (RO) membrane processes. The biofouling experiment was performed by filtrating nutrient-containing feed water with a cross-flow cylindrical membrane cell through a circular polyamide RO membrane with pre-adhered Pseudomonas putida. The trans-membrane pressure (TMP) and stirring rates in the cell were controlled as operating conditions. The stirring rates brought about shear force and thus corresponded to cross-flow velocities on the membrane surfaces in commercial operations. Permeate flux was monitored during the filtration, and bacterial adhesion to the membrane surfaces was observed using a confocal laser scanning microscope. An increase in TMP increased both the reduction rate of permeate flux and the volume of adhered bacteria, thus facilitating biofouling. Osmolarity calculation on the membrane surface suggested that TMP affected bacterial growth by concentration polarization (CP) of nutrients. Higher stirring rate prevented reduction of permeate flux and bacterial growth on membrane surfaces. The hydrodynamic shear force generated by stirring effectively detached the adhered bacteria, while CP of nutrients was not remarkably affected by the range of stirring rates used in this study. These results suggest that lower TMP and higher stirring rates prevent biofilm formation by decreasing CP and promoting bacterial detachment.

Platinum (Pt) nanosheets were developed by exfoliating layered platinum oxide. Moreover, we succeeded in synthesizing monolayer Pt nanosheets for the first time by adjusting the conditions for reduction. Monolayer Pt nanosheets were highly active in oxygen reduction reaction.

The fluorescence signal of a DNA sensor based on strand exchange on graphene oxide was amplified using a DNA circuit that consisted of autonomous cyclic reactions catalyzed by the target. Selectivi...

The thermal stability of the parallel motif triple helix DNA containing CG.CH+ base triplets is improved by silver ions. The N3 protons of cytosines on the third strand are replaced by the ions to ...

The bifunctional chelating fiber, FNPS, was prepared from vinylbenzyl chloride (CMS) grafted polyethylene-coated polypropylene fiber (PPPEf-g-CMS). In addition to the primary iminodi(methylphosphonate) chelating groups, FNPS has sulfonate groups as secondary functional group. FNPS was prepared by the following four steps. First, PPPEf-g-CMS was reacted with potassium phthalimide to substitute chlorine atoms in PPPEf-g-CMS with phthalimide groups. Second, sulfonate groups were introduced into the phenyl groups of benzyl moieties on the grafted polymer chains by the reaction with 95% sulfuric acid. Third, phthalimide moieties were hydrolyzed with ethanol solution of hydrazine hydrate to give the primary amino groups at the end of benzyl moieties on the grafted chains. Finally, these primary amino groups were converted into iminodi(methylphosphonate) groups by Mannich condensation reaction, in which the precursory fiber was reacted with large excess phosphorous acid and paraformaldehyde in 6 M hydrochloric acid media under the refluxed conditions for 6 h., The sulfonate and iminodi(methylphosphonate) groups in the resulting FNPS were identified by FT-IR spectroscopy. Contents of nitrogen, phosphorus, and sulfur in FNPS were found to be 1.53, 2.80, and 0.99 mmol/g, respectively. The phosphorus to nitrogen molar ratio was 1.83. This is very close to the ideal value of 2. The sulfur to nitrogen molar ratio was 0.65. The column-mode test on the Cu(II) uptake from a 0.1 mM Cu(II) aqueous solution revealed that FNPS can take up Cu(II) rapidly even in the extremely high feed flow rate range from 1000 to 7000 h-1 in space velocity. The breakthrough capacity of FNPS for Cu(II) is as high as ca. 0.8 mmol/g at the flow rate of 7000 h -1. In addition, it is expected that the FNPS packed column will make it possible to purify huge volumes of waters contaminated with 10-4 M levels of Zn(II), as long as the concentrations of the co-existing Ca(II) and Mg(II) are nearly equal to those in river waters.

Introduction/Background Exercise intensity is essential for exercise prescription. The estimation by heart rate can indicate intensity, however, this measurement can have limited accuracy, especially for low intensity exercise. One reason for inaccuracy is that exercise intensity calculations are based on heart rate at awake rest, which can easily fluctuate. In this study, we examined the validity of exercise intensity estimates generated from heart rate monitoring during sleep, which could be more stable than conscious waking heart rates. Material and method Fourteen healthy subjects participated to this study. VO2 max was determined by a maximal treadmill test to volitional exhaustion using the Bruce protocol. Maximum heart rate was estimated using age. To estimate exercise intensity during low intensity exercise, subjects participated in a six-minute distance walk (6MD). Exercise intensity was calculated using percent VO2 reserve (%VO2R), percent VO2max (%VO2max), and percent heart rate reserve based on heart rate during awake rest (HRR-a) and sleep (%HRR-s). To monitor heart rate at rest and during sleep, we employed a “smart clothing” system (Hitoe® system). Results Both %HRR-a and %HRR-s were significantly correlated with %VO2R and %VO2max. The correlation coefficient with %HRR-s tended to be higher than that of %HRR-a. The Bland-Altman plot showed systematic error in both %HRR-a and %HRR-s, with less error in %HRR-s. Conclusion Estimation of exercise intensity using heart rate during sleep may be easier and more accurate to monitor than waking heart rate, making it more feasible in clinical settings.

Salmon egg cells were the subject of investigation for all-elements analysis in a single biological cell, where the elements in egg cells were simultaneously determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) after microwave-assisted acid digestion. As a result, 74 elements among 78 stable isotope elements were determined or detected, although H, C, N, and O were determined separately by conventional CHN elemental analysis. In addition, the survey of protein-binding metallic elements as well as metalloid elements in salmon egg cell cytoplasm was performed by the fractionation analysis with a hyphenated system of high-performance liquid chromatography (HPLC)/ICP-MS using a 3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate (CHAPS)-coated octadecylsilyl silica (ODS) column and a size exclusion chromatography (SEC) column.

Chemical speciation of arsenic species in human blood serum was performed by high-performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICP-MS) with direct sample inj...

A multiply hyphenated HPLC/UV/ICP-MS system equipped with a fraction collection valve for subsequent MALDI-TOF-MS analysis was constructed, and its applicability to the speciation of metalloprotein...

Chemically engineered DNAs—in which global conformation can be modulated in response to specific stimuli—could be allosteric functional DNAs themselves or work as a modulator of the functional nucleic acids such as DNAzymes and aptamers. Here, we show that two terpyridines built in the DNA backbone form a stable intramolecular 1:2 complex, [M(terpy)2](2+), with divalent transition metal ions. Upon complexation, the DNA conjugates adopt a Ω-shape structure, in which two distal sequences located outside the terpyridines connect with each other to form a continuous segment with a specific structure or sequence. Such a DNA structure is globally controlled by local metal complexation events that can be rationally designed based on general coordination chemistry. This method is regarded as metal ion-directed dynamic sequence edition or DNA splicing. DNAzymes with peroxidase-like activity can thus be regulated by several transition metal ions through sequence edition techniques based on the Ω-motif.

Assay of alkaline phosphatase (ALP) in salmon egg cell cytoplasm was performed by size exclusion chromatography (SEC) with fluorescence detection of enzymatic activity and element-selective detecti...

Chemical speciation of arsenic in human urine was performed by HPLC separation with ICP-MS detection in order to investigate the urinary excretion patterns of arsenic metabolites after one-time ingestion of an edible seaweed, hijiki (Hizikia fusiforme). A Japanese male volunteer ingested one serving of ca. 15 g (dry weight) of hijiki (containing ca. 0.9 mg of arsenic), and urine samples were collected at 3-5 h intervals for the following 3 days. As a result, different urinary excretion patterns were observed between inorganic and methylated arsenicals. Toxic inorganic As(V) and As(III) were detected in the urine 3 h after ingestion. The highest concentrations of As(V) and As(III) were observed at 6 and 15 h after ingestion, respectively. In contrast, methylated arsenic species in the urine, such as monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and arsenobetaine (AB), began to increase 10 h after ingestion and provided the highest concentrations at 21 h after ingestion. These results indicate that a large amount of As(V) from hijiki is excreted rapidly in urine and some part of it is reduced to As(III) in the human body. As(III) may then be converted to non-toxic methylated arsenic species and excreted in urine later than inorganic ones. It can be concluded from these experimental results that detoxification of arsenic occurs in the human body through the rapid urinary excretion of toxic arsenicals or by conversion to organic methylated ones after ingestion of hijiki.

A versatile molecular device (lanthanide-complex molecular beacon; LCMB) was prepared by tethering ethylenediaminetetraacetic acid to the 5'-end and 1,10-phenanthroline to the 3'-end of stem-loop structured DNA as metal-capturing and sensitizer moieties, respectively. The emission from LCMB responded to the target molecule through the reversible structural change.

The speciation of diverse elements in salmon egg cell cytoplasm was performed by a surfactant-mediated HPLC/ICP-MS hyphenated system. In the present experiment, an ODS column coated with CHAPS (3-[(3cholamidopropyl)dimethylammonio]-1-propanesulfonate), which is a zwitterionic bile acid derivative, was employed as a surfactant-mediated separation column, and ICP-MS was used as an element-selective detector. The present surfactantmediated HPLC allowed us to separate large and small molecules within 10 min; large molecules, such as proteins, were eluted within 2.5 min, while small molecules were eluted after 2.5 min, but within 10 min. In the present experiment, Fe, Cu, and Zn in egg cell cytoplasm were observed mostly in species with large molecular weights, indicating that these elements are contained as metalloproteins or metalloenzymes in egg cell cytoplasm. On the contrary, it was found that P, S, Mo, and halogens in egg cell cytoplasm were contained as small molecules or inorganic ions. The major species of P in egg cell cytoplasm was identified as the phosphate ion (PO 4 3‐ ). Molybdenum, Cl, and Br in egg cell cytoplasm were molybdate (MoO4 2‐ ), chloride (Cl ‐ ), and bromide (Br ‐ ) ions, respectively.

A multielement determination of major-to-trace elements in black tea leaves and their tea infusions was carried out by ICP-AES (inductively coupled plasma atomic emission spectrometry) and ICP-MS (inductively coupled plasma mass spectrometry). Tea infusions were prepared as usual tea beverage by brewing black tea leaves in boiling water for 5 min. About 40 elements in tea leaves and tea infusions could be determined over the wide concentration range in 8 orders of magnitude. The extraction efficiency of each element was estimated as the ratio of its concentration in tea infusions to that in tea leaves. From the experimental results for the extraction efficiencies, the elements in black tea leaves were classified into three characteristic groups: (i) highly-extractable elements (>55%): Na, K, Co, Ni, Rb, Cs and Tl, (ii) moderately-extractable elements (20 - 55%): Mg, Al, P, Mn and Zn, and (iii) poorly-extractable elements (

The multielement determination of major-to-ultratrace elements in plant reference materials (SRM Pine Needles, SRM Tomato Leaves, and NIES Tea Leaves) was carried out by ICP-AES (inductively coupled plasma atomic emission spectrometry) and ICP-MS (inductively coupled plasma mass spectrometry). The plant sample was decomposed with nitric acid and hydrofluoric acid in a Teflon beaker on a hot plate. The digest was dissolved in 1 M HNO3 solution, and then subjected to elemental analyses. As a consequence, the analytical data for about 40 elements including rare earth elements (REEs) were obtained over a wide concentration range, for example, from 49600 µg g-1 of Ca to 6.2 ng g-1 of Lu in Tomato Leaves. The enrichment factors, which were estimated by normalizing the observed concentrations of analyte elements in plant reference materials to their soil abundances, were evaluated in order to discuss the relative abundances of various elements between plants and soil. It was found that most of the elements, except for REEs in Pine Needles and Tea Leaves, were significantly accumulated in the plant reference materials. In particular, the essential elements (K, Mg, Ca, Mn, Cu, Zn, B and P) for plant growth provided large enrichment factors.

飲料に供される緑茶葉の元素組成と溶出成分を調べるために,誘導結合プラズマ発光分析法(ICP-AES)及び誘導結合プラズマ質量分析法(ICP-MS)を用いて主成分から超微量成分までの多元素定量を行うとともに,サイズ排除クロマトグラフィー(SEC)を併用する化学形態別分析を行うことを目的とした。多元素定量分析の結果,緑茶要試料の酸分解溶液について%レベルの主成分元素からng g-1レベルの超微量元素までの40元素の定量を行うことができた。また,緑茶葉試料中の成分を熱水によって抽出した熱水浸出液では,29元素の定量値が得られた。これらの緑茶葉中の全元素量と熱水浸出液中の元素量の比から,各元素の緑茶葉からの浸出率を求めた。その結果,緑茶葉中の元素は浸出率が55%以上(Na,K,Co,Ni,Rb,Cs),20～55%(Mg.Al,P,Mn,Zn,Tl),20%以下(Ca,Fe,Cu,Sr,Y,Zr,Mo,Sn,Ba,希土類元素,Pb)の三つの元素群に分類された。更に,SEC,UV吸収検出器,ICP-AES又はICP-MSをオンラインで結合した複合分析システムにより,緑茶葉浸出液中元素の化学形態別分析を行った。その結果,SECクロマトグラム中に20元素が検出され,それぞれの元素が結合した化学種の分子量に関する知見が得られた。

誘導結合プラズマ質量分析法(ICP-MS)及び誘導結合プラズマ発光分析法(ICP-AES)を用いて,野菜試料中の多元素定量を以下のように行った。まず,ホウレンソウ乾燥試料0.5gをテフロンビーカーに入れ,硝酸とフッ化水素酸を加えてホットプレート上で加熱分解した。この溶液化した試料を内標準元素(Ge,In,Re各10ppb)を含む1mol dm-3HNO3溶液に調製後,ICP-AES及びICP-MSで測定し,%レベルで存在する元素からppbレベルで存在する元素まで約40元素の定量値を得た。また,異なる産地で栽培されたホウレンソウ試料について,元素濃度の平均とそのばらつきの大きさを検討した。主成分及び少量元素の中で,B,Mg,P,Kの濃度は試料によるばらつきが小さく,一方Ca,Na,Al,Mnについては変動係数が50%以上となった。微量元素及び超微量元素の変動係数は全般的に高く,100%を超える場合も見られた。更に,本分析法を11科23種類の野菜の多元素定量分析に応用し,野菜の種類による元素濃度の類似性と差異を明らかにした。

Fluorescent dye-labeled probe DNA was immobilized on fluorescence-quenching graphene oxide (GO) through a capture DNA. When targets were added, the probes were released from the GO through toehold-mediated strand exchange. Higher emission recovery and more signal contrast were achieved relative to conventional methods that are based on direct adsorption of probes.

Peptide nucleic acid (PNA) conjugates incorporating a bipyridine unit were prepared. The bipyridine was built into the loop moiety of PNAs that were designed to specifically form a hairpin and a PNA/DNA bimolecular triplex. While the thermal stability of the hairpin structure was only minimally affected by Cu(2+) addition, the PNA/DNA bimolecular triplex structure was significantly destabilized by complexation with Cu(2+). The melting temperature of the bimolecular triplex decreased by 17.4 °C in the presence of Cu(2+). This corresponds to more than a 1000 fold decrease in the binding constant for bimolecular triplex formation. Upon complexation, the bipyridine unit underwent a drastic conformational change which accounts for the observed differences in the thermal stabilities of the triplex upon binding. The bipyridine-PNA conjugate may be useful as an allosteric DNA carrier that releases the DNA in response to a certain metal ion concentration.

We propose a binary fluorimetric method for DNA and RNA analysis by the combined use of two probes rationally designed to work cooperatively. One probe is an oligonucleotide (ODN) conjugate bearing a β-cyclodextrin (β-CyD). The other probe is a small reporter ligand, which comprises linked molecules of a nucleobase-specific heterocycle and an environment-sensitive fluorophore. The heterocycle of the reporter ligand recognizes a single nucleobase displayed in a gap on the target labeled with the conjugate and, at the same time, the fluorophore moiety forms a luminous inclusion complex with nearby β-CyD. Three reporter ligands, MNDS (naphthyridine–dansyl linked ligand), MNDB (naphthyridine–DBD), and DPDB (pyridine–DBD), were used for DNA and RNA probing with 3′-end or 5′-end modified β-CyD–ODN conjugates. For the DNA target, the β-CyD tethered to the 3′-end of the ODN facing into the gap interacted with the fluorophore sticking out into the major groove of the gap site (MNDS and DPDB). Meanwhile the β-CyD on the 5′-end of the ODN interacted with the fluorophore in the minor groove (MNDB and DPDB). The results obtained by this study could be a guideline for the design of binary DNA/RNA probe systems based on controlling the proximity of functional molecules.

The incidence of implantable arterial post-related bloodstream infections (IAP-RBSI) among patients with unresectable hepatic malignancies is not well defined. We reviewed the 9-year incidence of implantable arterial post-related bloodstream infections in patients with hepatic malignancies, at a tertiary care center in Japan. The incidence was 1.9 infections per 10,000 catheter-days.

Speciation of mercury in salmon egg cell cytoplasm was investigated by surfactant-mediated high-performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICP-MS), where an ODS (octadecylsilica) column coated with a bile acid derivative, CHAPS (3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate), was used for species separation. Prior to the speciation analysis, total Hg in the cell cytoplasm was determined by ICP-MS at m/z 202 in a flow injection mode. For the precise measurement, salmon egg cell cytoplasm was diluted five-fold with 0.1M Tris (Tris(hydroxymethyl)aminomethane)-HNO(3) buffer solution, and the standard addition method was employed. Thus, the total concentration of Hg in cell cytoplasm was estimated to be 12.4ngg(-1) on the wet weight basis. Next, the cell cytoplasm diluted five-fold with 0.1M Tris-HNO(3) buffer solution was analyzed by surfactant-mediated HPLC with the dual detection system of a UV absorption detector and an ICP-MS instrument. Two peaks corresponding to some proteins and small molecules were mainly observed in those chromatograms. When salmon egg cell cytoplasm was diluted five-fold with 0.01M Tris buffer solution or pure water, some precipitates appeared probably because of precipitation of hydrophobic proteins in cytoplasm. After the precipitates were eliminated with a membrane filter, the filtrate was subjected to the analysis by surfactant-mediated HPLC/UV/ICP-MS. As a result, the peaks for small molecular species of Hg were clearly observed at the retention time near 4.0min (corresponding to low-molecular weight zone) in the chromatograms with UV absorption detection as well as with Hg- and S-specific ICP-MS detections. The small molecule bound with Hg was identified as cysteine through the cysteine-spiked experiment. In addition, the protein fraction on the chromatogram obtained by using the CHAPS-coated ODS column was further analyzed by SEC (size exclusion chromatography). Consequently, several protein peaks with molecular weight of 300, 50 and 12kDa were observed in all the detections of UV absorption, Hg and Se, although two peaks among them were coincident in the case of S. These results indicate that Hg in salmon egg cell cytoplasm binds with proteins containing selenocysteine and/or cysteine residues in proteins.

The major-to-ultratrace elements in human bone-marrow fluid were determined by ICP-AES (inductively coupled plasma atomic emission spectrometry), and ICP-MS (inductively coupled plasma mass spectrometry). The bone-marrow fluid sample was centrifuged prior to acid digestion to exclude the bone piece from bone marrow, and then digested with nitric acid. As a result, 20 elements could be determined over the concentration range from 1610 microg g(-1) for Na to 0.00043 microg g(-1) for W. It was found that Fe, Zn and Sb were enriched by ca. 264-, 7- and 15-fold, respectively, in bone-marrow fluid, compared to those in human blood serum. Alkali metals (K, Rb, Cs), except for Na, were also significantly enriched in bone-marrow fluid. Furthermore, the concentrations of various elements, such as Fe, P, Al, Zn, Cu, Se, Zr, Sn, Ag and W, were significantly higher than those in open seawater.

The total concentrations of some trace elements in blood serum are generally used as convenient parameters in medical diagnosis because of their extreme importance for diagnosis of health and disease,1 as well as their easy accessibility. However, most of the trace elements in blood serum are combined with biological substances to have their own specific functions. Therefore, more information about chemical species of the elements, in addition to the total concentrations,2,3 is required for the investigations on the biological and physiological functions of trace elements as well as for biomedical diagnosis of the physical conditions. Chemical species of trace elements in blood serum are generally divided into two chemical forms. 2 One is protein-associated species, which play important roles in enzymatic activities, and in transportation and storage of trace elements. The other is protein-non-associated species, which are related to membrane transport or excretion of the elements. In a previous work, 4 the present authors developed a surfactant-mediated chromatographic separation system which allowed simultaneous multi-component separation, based on the mixed-mode separation properties such as size-exclusion, electrostatic and hydrophobic interactions. In this system, large-molecule species (MW 6500‐2000000) were eluted within 3 min of elution time, while small-molecule species (MW< 1000) were eluted after 3.5 min. Thus, the surfactant-mediated separation system could be used for direct injection analysis of the serum samples to separate small-molecule drugs rapidly from proteins in human blood serum without any pretreatment, 4 where the UV absorption detector was employed. Since the surfactant-mediated separation column also allows us to couple with inductively coupled plasma mass spectrometry (ICP-MS) for simultaneous multielement detection, the HPLC/ICP-MS combined system using the surfactant-mediated separation column can be applied to speciation of trace elements in blood serum with direct sample injection. In the present paper, we report a preliminary study on speciation of trace elements binding and non-binding with proteins in human blood serum which was carried out by using the surfactant-mediated HPLC/ICP-MS system. The HPLC system was composed of a pump (Model LC10AD; Shimadzu, Kyoto), a sample injector (Model V7, Pharmacia-LKB, Uppsala, Sweden) with a 20 µl sample loop, and a UV absorption detector (Model 870-UV; Jasco, Tokyo). The UV detector was used for detection of UV-absorbing species. In the present experiment, an ODS column (L-column; 4.6 mm i. d. × 250 mm long; Chemical Inspection and Testing Institute, Tokyo) dynamically coated with 3-[(3-cholamidopropyl)dimethylammonium]-1-propanesulfonate (CHAPS), zwitterionic bile acid derivative, was employed as the separation column. The CHAPS-coated ODS column was prepared in a manner similar to that used in the previous paper. 4 The mobile phase of 0.2 mM Tris‐HCl buffer solution (pH 7.4) was used at a flow rate of 0.7 ml min ‐1 , into which 0.2 mM CHAPS was added to prevent the degradation of the separation column. For the on-line element-selective detection, an ICP-MS instrument (Model SPQ8000A, Seiko Instruments, Chiba) was used with direct introduction of the eluent from the column into the nebulizer of ICP-MS via a Teflon tubing. The ICP-MS instrument was operated using a time-sequential program, which allowed simultaneous multielement chromatogram measurements. The human blood serum samples were obtained from healthy volunteers. The sampling and pretreatment procedures of the serum samples were performed in a manner similar to those in the previous paper. 5 The CHAPS-coated ODS column with diverse physicochemical properties can separate a variety of solutes, such as inorganic anions, amino acids, aromatic compounds, and

Composite ceramics of MgO mixed with SiC fine powder up to 90vol% were fabricated by the hot-pressing at 1700°-1900°C under 30MPa for 30min. The properties (bending strength, fracture toughness, hardness, oxidation-resistance et al.) of the hot-pressed bodies were measured. Fairly dense MgO-SiC composite ceramics with relative densities above 95% were obtained in the region of SiC content up to 50vol% at a sintering temperature of 1850°C. The composites containing 30-50vol% SiC had higher strength, hardness and thermal shock resistance than MgO monolithic compacts. Little decrease in the strength was observed at temperatures up to 1400°C because of surpressing the fracture of MgO at grain boundary by SiC particles. The fracture toughness (about 5MPa·m1/2) of composite with a SiC content of 30vol% was two and half times as large as that of hot pressed MgO at 1400°C. This is considered to be due to the crack deflection by SiC particles. This composite ceramics showed poor oxidation-resistance, so that the high-temperature uses must be limited in certain range.