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The measurement protocol of solid particle number with the lower detection limit (D50) at 10 nm (SPN10) is planned to be implemented in European emission regulations by means of laboratory-grade measurement systems. Furthermore, SPN10 measurement as the real driving emissions (RDE) regulations is under development by defining appropriate technical specifications for the portable emissions measurement system (PEMS). It is under discussion to implement SPN10 limits as one of additional pollutants to the new European emissions regulations, so-called “Euro 7”. As the Consortium for ultra LOw Vehicle Emissions (CLOVE) has proposed, RDE testing by means of PEMS will be the primary means of emissions determination for certification purposes. Measurement equivalency between laboratory-grade emissions measurement systems and PEMS is still important due to the necessity of validation in laboratories before on-road testing by comparing determined emissions by both. The current draft technical requirements for SPN10 measurement in laboratory and on-board allow certain difference in detection efficiencies, especially around the D50 of 10 nm. However, good agreement in the efficiencies between the commercially available laboratory systems and PEMS was observed experimentally by using similar measurement principles based on condensation particle counters (CPCs). The results suggested that the difference in detection efficiencies for the applicable particle size range greater than 10 nm between the laboratory system and PEMS could be within ±10%. Moreover, it is found that the entire system detection efficiencies calibrated directly were equivalent to the calculated efficiencies by individual calibration coefficients of the volatile particle remover and the CPC defined by the regulations.

The electro-gravitational aerosol balance (EAB) is a method of measuring the mass of nearly monodisperse aerosol particles using a Millikan-type cell. We propose in the present study a procedure fo...

A method to determine the cutoff diameter and counting efficiency of single-particle optical particle counters (OPC) is presented. An aerodynamic aerosol classifier (AAC) coupled with an atomizer was used to generate monodisperse dioctyl phthalate particles with a condensation particle counter (CPC) as the reference instrument. This method is accurate for capturing the counting efficiency of OPCs at lower size ranges and determining the cutoff diameter. The CPC was found to be a poor reference instrument for particles larger than 1 µm in which case an inkjet aerosol generator (IAG) was used as the monodisperse particle source and reference instrument. Two different particle materials were used with the IAG: lactose monohydrate and an ionic liquid (1-ethyl-3-methylimidazolium trifluoromethanesulfonate). A combination of the AAC to size smaller particles ( µm) and IAG to generate larger particles (>1 µm) was found to provide a comprehensive method capable of covering the counting efficiency over the entire operating range of OPCs. Copyright © 2020 American Association for Aerosol Research

We have developed a measurement method that enables accurate determination of the number concentration of liquid-borne particles by adopting simultaneous particle counting and mass measurement. The new measurement method consists of an optical particle counter (OPC) for particle counting, an electronic balance for mass measurement, a syringe pump for sampling, and a pulse height analyzer for signal processing. We refer to this method as the mass-measurement-type optical particle counting (M-OPC) method. The M-OPC method facilitates both metrological traceability of the mass of measured suspensions and evaluation of the counting efficiency of OPCs. Using the M-OPC method, we evaluated the measurement accuracy of two different types of OPCs: a light-scattering type and a light-extinction type. The validity of the measurement results obtained with the M-OPC method was examined by comparison with the results of an independent microscopic method using a scanning electron microscope (SEM). The M-OPC method also offers the possibility of calibrating the number concentration of particles in suspensions with diameters from the sub-micrometer to micrometer range by combining multiple OPCs. This method is expected to be used as the national primary standard at the National Metrology Institute of Japan of the National Institute of Advanced Industrial Science and Technology.

Main text This report presents the results of CCQM-K150, a key comparison between nine National Measurement Institutes (NMIs) which tested the capability of the NMIs to measure particle number concentration (in the range of 100 to 20 000 cm-3) using condensation particle counters (CPCs), and particle charge concentration (in the range of 0.15 to 3 fC cm-3) using aerosol electrometers (AEs). Measurements of aerosol particle number concentration are needed to demonstrate compliance to vehicle emission legislation and are becoming increasingly important in other areas such as ambient air and workplace monitoring. The measurements are typically carried out using condensation particle counters, which are calibrated using either reference CPCs or reference AEs. An analogous report is available for the CCQM-P189 comparison. CCQM-P189 was identical to and used the same experimental data as CCQM-K150 with one exception: data from TROPOS, which is not an NMI or Designated Institute (DI), were only included in CCQM-P189. CCQM-K150 was an amount-of-substance Track C comparison. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text This report presents the results of CCQM-P189, a pilot comparison between 10 laboratories which tested the participants’ capability to measure particle number concentration (in the range of 100 to 20 000 cm-3) using condensation particle counters (CPCs), and particle charge concentration (in the range of 0.15 to 3 fC cm-3) using aerosol electrometers (AEs). Measurements of aerosol particle number concentration are needed to demonstrate compliance to vehicle emission legislation and are becoming increasingly important in other areas such as ambient air and workplace monitoring. The measurements are typically carried out using condensation particle counters, which are calibrated using either reference CPCs or reference AEs. An analogous report is available for the CCQM-K150 comparison. CCQM-K150 was identical to, and used the same experimental data as CCQM-P189 with one exception: data from TROPOS, which is not a National Measurement Institute (NMI) or Designated Institute (DI), were only included in CCQM-P189. CCQM-P189 was an amount-of-substance Track C comparison. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

This study introduces a method to deposit polystyrene latex (PSL) particles on a silicon wafer in a manner that allows their number to be predicted with a high degree of accuracy. A laminar...

The most important parameter for light-scattering measurements in the Rayleigh scattering region is the Rayleigh ratio, which is necessary to obtain the absolute scattered light intensity from the relative scattered light intensity. The absolute scattered light intensity is directly related to the molar masses of polymers, colloids, biomolecules, and the like. A new Rayleigh ratio was determined by measuring static light scattering from certified reference materials with highly accurate certified values of the molecular weight determined by several other techniques, such as MALDI-TOF mass spectrometry or size-exclusion chromatography. The new Rayleigh ratio can be used for evaluating the uncertainty of the molecular weight of polymers and macromolecules, as measured by light scattering.

The first bilateral comparison of particle number concentration (PNC) standards via calibrating the counting efficiency (CE) of an optical particle counter (OPC) at high concentration of 1000 cm-3 is reported. An OPC (GRIMM 11-D) has been used as the transfer standard between NMC and NMIJ, with its CE being calibrated using monodisperse polystyrene latex (PSL) particles around 0.3 µm by the Faraday Cup Aerosol Electrometers (FCAE) of both metrology institutes. The CE of the OPC has been evaluated for a series of increasing concentrations to determine the highest concentration level which is free from coincidence loss. The OPC was also calibrated at 0.5 µm using an inkjet aerosol generator (IAG) and FCAE to compare its CE at different concentration levels. We have analysed the CE’s stability at decreasing concentration levels from 1228 to 0.5 cm-3 to derive the evidence for the equivalence of CE at different concentration levels. The CE values of the OPC around 0.3 and 0.5 µm measured by two institutes have agreement within 1.5% (normalized error En

This study introduces the method to evaluate the counting efficiencies of optical particle counters (OPCs), , at particle diameter greater than 1 μm by using an inkjet aerosol generator (IAG). This study demonstrates the evaluations at 5 and 10 μm in volume equivalent diameter. The chemical composition of the particles is either sodium chloride or lactose monohydrate. The aerosol flowrate of the IAG is set at 0.3 L/min, and the aerosol is delivered to an OPC with sampling flowrate 6 L/min (Omron, ZN-PD50S). The mismatch of the flowrates is compensated for by adding particle-free air in a laminar flow chamber. In order to simulate the sampling of uniformly mixed aerosol from a real environment, the particles are delivered to different points over the inlet plane of the isokinetic probe attached to the OPC. Particle flux into the isokinetic probe is proportional to the gas-velocity into the probe; however, the true velocity distribution is usually unknown. It is assumed that the true velocity distri...

A new nebulizer called NanoAerosol Generator (NAG) by Kanomax FMT, Inc. was evaluated experimentally in their performance in aerosolizing sub-100 nm particles and sub-10 nm protein molecules which cannot be aerosolized with conventional compressed-air jet nebulizers due to the interference by a number of residue particles. For the challenge particles, 29 nm-polystyrene latex (PSL) particles and bovine serum albumin (BSA) protein molecules were used as sub-100 nm and sub-10 nm test materials, respectively. For both particles, the aerosolization by the NAG was successful with a clear separation between the peak of the challenge particles and the peak of residual particles in the size distribution spectra. The size distributions of aerosolized 29 nm-PSL particles were compared between the NAG and an electrospray aerosol generator (EAG) with liquid samples of the same particle concentration. The EAG showed clearer separation of the PSL peak from the residual peak; on the other hand, the peak height was taller for the NAG by a factor of 6 than for the EAG, which indicated the generation of airborne particles from a liquid suspension/solution of the same concentration was more efficient for the NAG than for the EAG.

In this study, we present a traceable method for determining the counting efficiency of optical particle size spectrometers (OPSS), also known as aerosol spectrometers. The primary standard consists of an aerosol generation setup, a vertical flow tube for particle homogenization and a reference optical particle counter. The OPSS under testing and the reference optical particle counter sample aerosol simultaneously through specially designed isokinetic sampling probes at number concentrations ranging from 0.5 cm−3 up to several hundred particles per cm3 (depending on the particle size). Calibration in terms of particle size relies by convention on the use of certified PS (polystyrene) spheres in the size range 100 nm - 10 μm. Here, the counting efficiency profiles of two commonly used OPSS, namely the Model 3330 OPS (TSI Inc., USA) and the 11-D monitor (Grimm GmbH, Germany) are presented for the first time and discussed within the context of the ISO 21501–1:2009 and 21501–4:2018 standards on the calibration of OPSS for indoor/outdoor measurements and optical particle counters (OPC) for clean rooms applications, respectively. We believe that this study can help manufacturers improve the design of their instruments, contribute to the further development of relevant national and international standards and pave the way for a standardised and traceable calibration of OPSS units installed at air quality monitoring stations and industrial/workplace environments.

A butanol-type ultrafine condensation particle counter (UCPC, Model 3776, TSI, Inc., Shoreview, MN, USA), which can achieve a 50% detection efficiency diameter (d50) of 2.5 nm using a capillary-sheath structure, was modified and tested in the laboratory for airborne measurements. The aerosol flow rate through the capillary is a key factor affecting the quantification of aerosol particle number concentrations. A pressure-dependent correction factor for the aerosol flow rate was determined using a newly added mass flow meter for the sheath flow and the external calibration system. The effect of particle coincidence in the optical sensing volume was evaluated using an aerosol electrometer (AE, Model 3068B, TSI, Inc.) as a reference. An additional correction factor for the coincidence effect was derived to improve the quantification accuracy at higher concentrations. The particle detection efficiency relative to the AE was measured for mobility diameters of 3.1–50 nm and inlet absolute pressures of 101–40 kPa. The pressure dependence of the d50 value, asymptotic detection efficiency, and shape of the particle detection efficiency curve is discussed, along with simple theoretical calculations for the diffusion loss of particles and the butanol saturation ratio in the condenser. © 2017 American Association for Aerosol Science

The flat surface of Nuclepore filters is suitable for observing collected particles with a scanning electron microscope (SEM). However, experimental data on surface-collection efficiency are limited because surface-collection efficiencies cannot be measured directly using aerosol measuring instruments. In this study, the surface-collection efficiencies of Nuclepore filters were determined by establishing the ratio of the number of particles deposited on the surface of the filter visually counted with an SEM to the number of inflow particles counted by a condensation particle counter, using monodispersed polystyrene latex particles (30–800 nm) and silver particles (15–30 nm). Because Nuclepore filters with smaller pore sizes would be expected to produce higher minimum surface-collection efficiency and a higher pressure-drop, 0.08 and 0.2 µm Nuclepore filters were chosen as the test filters in view of both collection efficiency and pressure drop. The results showed that the minimum surface-collectio...

We report on an inter-laboratory comparison for the calibration of light-scattering optical particle counters measuring the number concentration of airborne particles in the size range 300 nm–5 µm. This comparison, registered as EURAMET pilot study Nr. 1453, is an important first step towards internationally recognized SI traceability in the measurement of low particle number concentrations encountered in clean-room facilities. The participating particle metrology laboratories of NMIJ (Japan), DFM (Denmark) and METAS (Switzerland) each provided a portable optical particle counter as a transfer standard to be circulated amongst the partners. The comparison covered particle number concentrations up to about 2 cm−3. The individual measurements for the transfer standards at each laboratory are in good agreement with the reference value, typically within 7%, which supports the applied national primary methods of measurement.

The preparation of nanoscale fine bubbles in water is an innovative technology, but no precise method for simultaneously measuring the size and concentration of such bubbles had previously been developed. We have developed a method for simultaneously determining the size and concentration of fine bubbles in water by a light-scattering technique. Dynamic light scattering gives the diffusion constant and particle size of fine bubbles, whereas static light scattering provides their concentration or molar mass. Static light scattering also provides the radius of gyration of the bubbles, thereby providing a means for validating measurements of the sizes of the fine bubbles.

This paper discusses issues which will appear if the PMP methodology is extended to the measurement of particles with sizes below 23 nm. In addition, the origins of sub-23 nm particles from three different types of engines are discussed. An increased uncertainty was observed for the detection efficiency measurements with a particle number counter (PNC) at particle sizes below 10 nm. The particle concentration reduction factor (PCRF) of a volatile particle remover for 15 nm particles was higher than those for 30, 50 and 100 nm particles because of increasing particle losses. Then, exhaust particle emissions from a gasoline direct injection (DI) passenger car and trucks with and without a diesel particulate filter (DPF) were measured using the PMP methodology with a PNC whose D 50 value was 2.5 nm (PNC_2.5) and a normal PMP PNC (PNC_23). The fluctuations of the results for PNC_23 and PNC_2.5 were almost the same when the effect of re-nucleation of semi-volatile particles was removed. Different procedures for estimating the PCRF showed varying results, –23% to +41% in the worst case. The profiles of sub-23 nm particles from diesel trucks were similar to those of particles larger than 23 nm. In the case of the gasoline DI car, a peculiar emission corresponding to hydrocarbon nucleation was observed in high-speed operation. Particles emitted from the diesel engines originated from combustion processes in the case of the truck without the DPF and were strongly affected by the DPF conditions in the case of the truck with the DPF.

This article introduces an aerosol-based technique to make aqueous suspension of hydrophobic nanomaterial without adding dispersant. The method is intended for making a test-sample for evaluating the toxicities of nanomaterial by intra-tracheal administration. The method can wet the surface of hydrophobic nanomaterial within a few seconds. After the wetting process five to ten minutes of sonication assisted with manual stirring can fully disperse the hydrophobic nanomaterials in water. Two types of TiO2 nanomaterial were used in this study; Tayca JMT-150IB whose surfaces are coated with negatively charged hydrophobic functional group, and P25 whose surfaces are naturally hydrophilic. Nanomaterials are aerosolized by a dry-method and become micrometer-sized agglomerates. Then supersaturated water vapor is condensed onto these airborne agglomerates by using a growth tube collector. The collected suspension (CS) of hydrophobic nanomaterial (JMT-150IB) is prepared in two steps; airborne agglomerates are collected onto a flat surface then transferred to liquid-water and subsequently sonicated for complete dispersion. This method works equally well for making the CS of hydrophilic nanomaterial. Size distribution measurements of the CS show that airborne agglomerates of TiO2 dissociate into smaller units of agglomerates once they are captured into water, and the sizes of the agglomerates are in the nanometer to sub-micrometer range. Light scattering technique is used to show that a short sonication process can reproduce the particle number concentration of the CS after long storage. Copyright © 2017 American Association for Aerosol Research

A certified reference material (CRM) for poly(ethylene glycol) with no distribution in the degree of polymerization was developed. The degree of polymerization of the CRM was accurately determined to be 23. Supercritical fluid chromatography (SFC) was used to separate the molecularly uniform polymer from a standard commercial sample with wide polydispersity in its degree of polymerization. Through the use of a specific fractionation system coupled with SFC, we are able to obtain samples of poly(ethylene glycol) oligomer with exact degrees of polymerization, as required for a CRM produced by the National Metrology Institute of Japan.

We investigated changes in particle detection performance of a condensation particle counter (CPC) for automobile exhausts (model 3790, TSI Inc.) during an accelerated durability test with high particle loading. The CPC was exposed to carbon particles for over 100 h with a mode diameter of 80 nm at a number concentration of 106 cm−3, i.e., 100 times more than the maximum of the designed concentration range of the CPC specified by the manufacturer. This was equivalent to exposure at the designed maximum concentration (i.e., 104 cm−3) for five years. The detection efficiencies of the CPC evaluated regularly at 23, 41, and 55 nm during the test remained unchanged, which indicated that the particle loading was less than the level at which the performance of the CPC would be degraded by contamination of the interior of the CPC. Based on this observation, it was concluded that the changes in the detection performance of our customers׳ CPCs, which we observed occasionally during annual maintenance and recalibration, were due to causes other than particle loading within the designed concentration range. The unchanged detection efficiencies in our test of exposure equivalent to five years suggest that yearly calibration should be sufficient for maintaining the measurement accuracy of a CPC if it is operated under normal conditions.

A simple sampling method to collect aerosol particles for transmission electron microscope (TEM) analysis was developed by R’mili and others in 2013. The method involves passing air through a holey carbon film-coated copper mesh TEM grid (holey carbon grid) and sampling particles by filtration. In this study, we proposed a modified calculation method to represent the collection efficiencies of holey carbon grids, taking into consideration the porosity of the copper mesh. We then evaluated the particle collection efficiencies of holey carbon grids both theoretically and experimentally. We tested the collection efficiency of two types of holey carbon grids, with nominal pore sizes of 1.2 and 0.6 μm, using particles of monodispersed polystyrene latex (PSL) and potassium chloride. The overall collection efficiency of each grid (Egrid) was determined by the downstream/upstream concentration ratio measured by condensation particle counters (CPCs). In addition, for PSL particles, the collection efficiency of the...

This study presents the first systematic investigation of the anti-diabetic properties of non-oxido V(IV) complexes. In particular, the insulin-mimetic activity of [V(IV)(taci)2](4+), [V(IV)(inoH-3)2](2-), [V(IV)(dhab)2], [V(IV)(hyph(Ph))2], [V(IV)(cat)3](2-) and [V(IV)(pdbh)2]--where taci is 1,3,5-triamino-1,3,5-trideoxy-cis-inositol, ino is cis-inositol, H2dhab is 2,2'-dihydroxyazobenzene, H2hyph(Ph) is 3,5-bis(2-hydroxyphenyl)-1H-1,2,4-triazole, H2cat is catechol and H2pdbh is pentan-2,4-dione benzoylhydrazone--was evaluated in terms of free fatty acid (FFA) release. Among the six compounds examined, only [V(IV)(pdbh)2], [V(IV)(cat)3](2-) and [V(IV)(hyph(Ph))2], which at the physiological pH convert to the corresponding V(IV)O complexes, were found to exhibit a significant insulin-mimetic activity compared to VOSO4. In contrast, [V(taci)2](4+), [V(inoH-3)2](2-) and [V(dhab)2], which at pH 7.4 keep their 'bare' non-oxido structure, did not cause any inhibition of FFA. The results, therefore, suggest that a V(IV)O functionality is necessary for vanadium complexes to exhibit anti-diabetic effects. This agrees with the notion that the biotransformations of V compounds in the organism are more important than the nature of the species.

A compact aerosol particle mass analyzer (APM) of which the size of the classifier was significantly reduced than that of the first commercial model (Kanomax Model 3600) was developed. Firstly, requirements for desired performance in classifying particle mass were set forth. Secondly, a theoretical framework for the design parameters of an APM that satisfies the requirements was formulated. Thirdly, the design parameters were determined that satisfies the requirements while reducing the instrument size. The requirements include the condition that the classification range covers from 0.001 to 1000 fg (approximately 12 to 1200 nm in size for spherical particles having the density of 1 g/cm3), and the condition that both the classification resolution and particle penetration in this mass range are higher than certain specified values. A prototype having the design parameters determined according to this theoretical framework was constructed, and its performance was evaluated experimentally. The external dime...

We carried out a set of experiments to compare three particle number concentration standards (NCSs) by calibrating the same condensation particle counter (CPC) unit (Model 3772, TSI Inc., Shoreview, MN, USA). The standards were, in the order of operation size range, the primary NCS of the National Institute of Advanced Industrial Science and Technology (AIST, Japan), the Single Charged Aerosol Reference (SCAR) (Finland), and the Inkjet Aerosol Generator (IAG) of AIST. The results obtained with the 3 standards were found to agree at all overlapping particle sizes within the uncertainty limits. The relative expanded uncertainties varied between 0.6% and 2.6%, depending on the size and standard, while the overall agreement between the standards was within 0.5%. The observed consistency of the results is an important step toward establishing internationally coherent particle NCSs. As a result, the CPC 3772 was successfully calibrated in a particularly wide size range, approximately from 10 nm to 10 μm. The re...

We prepared [meso-tetrakis(4-carboxylatophenyl)porphyrinato]oxovanadium(IV) tetrasodium, ([VO(tcpp)]Na4), and investigated its in vitro insulin-mimetic activity and in vivo metallokinetic feature in healthy rats. The results were compared with those of previously proposed insulin-mimetic oxovanadium(IV)porphyrin complexes and oxovanadium(IV) sulphate. The in vitro insulin-mimetic activity and bioavailability of [VO(tcpp)]Na4 were considerably better than those of [meso-tetrakis (1-methylpyridinium-4-yl)porphyrinato]oxovanadium(IV)(4+) tetraperchlorate ([VO(tmpyp)](ClO4)4) and oxovanadium(IV) sulphate. On the other hand, [VO(tcpp)]Na4 and [meso-tetrakis(4-sulfonatophenyl) porphyrinato]oxidovanadate(IV)(4-)([VO(tpps)]) showed very similar in vitro insulin-mimetic activity and in vivo metallokinetic feature in healthy rats. In particular, the order of in vitro insulin-mimetic activity of the complexes was determined to be: [VO(tcpp)]Na4 ≈ [VO(tpps)] > ([VO(tmpyp)](ClO4)4 > oxovanadium(IV) sulphate.

Simultaneous and fractional determination of iron(II) and iron(III) was accomplished with o-hydroxyhydroquinonephthalein (QP) in the presence of poly (N-vinyl pyrrolidone). In the determination of total iron (iron(II)+iron(III)), Beer's law was obeyed in the range of 0.02-0.67 μg·ml−1, with an effective molar absorptivity (at 570 nm) and a relative standard deviation of 1.30×105·l·mol−1·cm−1 and 0.77% (n = 8), respectively. This method was about 10-15 times and more than the methods using 1,10-phenanthroline and 2,2′-bipyridine. In addition, the iron-QP complex was characterized using spectrophotometry and the electron spin resonance. This method was successfully applied to assays of total iron and iron(III) in pharmaceutical preparations.

In recent years, people all over the world have suffered from various diseases such as cancer, myocardial infarction, osteoporosis, hypertension, and diabetes mellitus (DM). Especially, DM, well-known as one of lifestyle-related diseases, has been regarded as a serious problem, because it is difficult to fully recover. The number of patients suffering from DM in 2007 was reported to be approximately 200 million people worldwide. However, insulin preparations and synthetic therapeutics, which are clinically used treatment of DM, have been associated with problems such as physical and mental pain due to daily injections and certain severe side effects, respectively. Zn, which is an essential trace element in animals and humans and plays an important role in maintenance of their lives, has been indicated to exhibit insulin-like activity. Since the finding of insulin-like effects of Zn, several Zn complexes have been proposed as a new type of anti-diabetic therapeutics which is differ from existing medicines. In this symposium, we introduce the anti-diabetic effect, complication relieving effect, and action mechanism of bis(2-mercaptopyridine-N-oxidato)Zn complex with Zn(S(2)O(2)) coordination mode.

At the National Metrology Institute of Japan (NMIJ), the triple point of neon was measured using an NMIJ sealed cell, NMIJ Ne-5, and a modular sealed-cell model, Ec2Ne, made by the Istituto Nazionale di Ricerca Metrologica (INRiM) in Italy, and the results were compared. The melting curves obtained with the NMIJ Ne-5 cell show narrow widths (0.1 mK) over a wide range of the inverse of the melted fraction (1/F) from 1/F = 1 to 1/F = 10, which is consistent with a previous report. On the other hand, the width of the melting curves obtained with the Ec2Ne cell is 0.15 mK from 1/F = 1 to 1/F = 10. The liquidus point Ttp estimated by the melting curves from F ~ 0.35 to F ~ 0.85 using the NMIJ cell is 0.05 mK higher than that using the Ec2Ne cell. The difference does not agree with the results obtained in an assay of the isotopic concentration from samples of the original Ne sources. The origin of the discrepancy has not been clarified yet.

Constant-volume gas thermometer (CVGT) measurements are conducted using 3He of three different densities as the working gas to obtain the thermodynamic temperature TCVGT and the second virial coefficient of 3He, B, at temperatures down to 3 K, using the triple point of Ne as a reference temperature. Densities of 127 mol · m−3 and 278 mol · m−3 are used in addition to the density of 168 mol · m−3 used in the measurement reported previously, where TCVGT was obtained using the virial coefficient adopted by the International Temperature Scale of 1990 (ITS-90), BITS-90. TCVGT is obtained by two methods, by the single- and multi-isotherm fitting of B to the three densities and by the method used in the previous work using one of the three densities and BITS-90. B obtained from the isotherm fitting agrees with BITS-90 within the uncertainty of the data used to derive BITS-90. Moreover, B obtained from a multi-isotherm fit agrees with that of recent theoretical ab initio calculations within 0.05 cm3 · mol−1 at 5 K and above, and within 0.3 cm3 · mol−1 down to 3 K. The values of TCVGT obtained from the multi-isotherm fits assuming different forms for the temperature dependence of B agree with each other within 0.1 mK. TCVGT obtained from the multi-isotherm fitting agrees with that obtained from the method in the previous report within 0.22 mK. The tendency of the difference between TCVGT and the ITS-90 temperature reported in the previous work is confirmed in the present work.

The performance of a condensation particle counter (CPC, Model 3771, TSI Inc.), which has a nominal minimum detectable particle size (d 50) of 10 nm, has been tested in the laboratory for the purpose of airborne measurements. First, the effects of particle coincidence at concentrations above the upper limit specified by the manufacturer (>104 cm-3 were evaluated. By applying a correction factor derived from experimental results, the CPC can quantify particle concentrations of as high as 5 × 104 cm– 3. Second, the effects of inlet pressure (p) on the size dependence of the detection efficiency were investigated (particle diameter (d)= 8–100 nm, p= 1010–300 hPa). The asymptotic detection efficiency and d 50 showed decreasing and increasing trends with decreasing pressure, respectively, especially at p < 600 hPa. It is likely reduction of the 1-butanol saturation ratio in the condenser at decreased pressures can explain the observed pressure dependence. Finally, the temporal variation of the detection effici...

We investigated, theoretically, the mass range in which an aerosol particle mass analyzer (APM) can be used for classification, and how the APM classification performance can be optimized. We listed factors that set limits to the APM, which were constraints of the rotation speed and the voltage, as well as requirements on the APM classification performance parameter, λ, that guarantee at least minimal performance in both resolution and penetration. We introduced the APM operation diagram, which is a tool to visualize the limits and mass range. We proposed to operate the APM that was considered in this study with the λ value set within the range from 0.25 to 0.5 for optimum classification performance by balancing both resolution and penetration. The mass range for the APM, with the λ value maintained between 0.25 and 0.5, was calculated to be from 0.003 to 2000 fg, which corresponds to the diameter range from 20 to 1600 nm for the density of 1 g/cm3. To verify the validity of the mass range and the idea of...

In recent years, the number of patients suffering from diseases, such as cancer, apoplexy, osteoporosis, hypertension, and type 2 diabetes mellitus is increasing worldwide. Type 2 diabetes, a lifestyle-related disease, is recognized as a serious disease. Various types of pharmaceutics for diabetes have been used. Since the relationship between diabetes and biometals such as vanadium, copper, and zinc ions has been recognized for many years, we have been developing the anti-diabetic metal complexes as new candidates. We found that several zinc(II) (Zn) complexes exhibit glucose-lowering activity for treating type 2 diabetes. High doses of salicylates have been known to reverse hyperglycemia and hyperinsulinemia in type 2 diabetic patients. These findings strongly suggest that the combined use of Zn and salicylates achieves the synergism in treating type 2 diabetes. Because aspirin, acetyl salicylic acid, has a chelating ability, we used it as a ligand to Zn. Several Zn-salicylate complexes were prepared and their biological activities were examined in this study. The complexes with an electron-withdrawing group in the ligand exhibited higher in vitro insulinomimetic activity than those of Zn complexes with an electron-donating group in the ligand. When bis(aspirinato)Zn (Zn(asp)₂) complex was orally administered on KK-A(y) mice with hereditary type 2 diabetes, the diabetic state was improved. In addition, this complex exhibited normalizing effects on serum adiponectin level and high blood pressure in metabolic syndrome. In conclusion, Zn(asp)₂ complex is newly proposed as a potent anti-diabetic and anti-metabolic syndrome agent.

We investigated the release potential of single-wall carbon nanotubes (CNTs) produced by the super-growth method during their manufacturing and handling processes at a research facility. We generally sampled air at points both outside and inside of protective enclosures such as a glove box and fume hood. Sampling the air outside of the enclosures was intended to evaluate the actual exposure of workers to CNTs, while sampling the air inside the enclosures was performed to quantify the release of CNTs to the air in order to estimate the potential exposure of workers without protection. The results revealed that airborne CNTs were generated when (1) CNTs were separated from the substrates using a spatula and placed in a container in a glove box; (2) an air gun was used to clean the air filters (containing dust that included CNTs) of a vacuum cleaner; (3) a vacuum cleaner was used to collect CNTs (emission with exhaust air from the cleaner); (4) the container of CNTs was opened; and (5) CNTs in the bin of the cleaner were transferred to a container. In these processes, airborne CNTs were only found inside the enclosures, except for a small amount of CNTs released from the glove box when it was opened. Electron microscopic observations of aerosol particles found CNT clusters, which were fragments of CNT forests, with sizes ranging from submicrometers to tens of micrometers.

Following the start of exploration of the problem of the effect of neon isotopes on the triple-point temperature in 2005, further progress was achieved in 2006–2008, and published in 2008. This paper summarizes the advances to date in our understanding as obtained from further work done in 2008–2009 on five basic aspects of the problem: new isotopic assays; new thermal measurements on neon of “natural” composition; the feasibility of obtaining a value of the slope dTtp/dx(22Ne) with an accuracy sufficient for the purpose; the possible occurrence of isotopic fractionation during the process of sealing the samples in the cells; and new thermal measurements on the pure isotopes 20Ne and 22Ne. The recently collected information is sufficient to state that it will eventually be possible to fulfill within 2010 the goal of recommending to the CCT solutions for the correction, with an accuracy fitting the purpose, of the neon isotopic effect on Ttp, to be included in a future revision of the Technical Annexe to the “mise en pratique” of the kelvin.

The current status and future needs of nanoparticle metrology are discussed, particularly with respect to measurements of size, size distribution and number concentration of airborne and liquid-borne nanoparticles. Possible classification of types of measurement standards is proposed, and the role of each type of standard, including the feasibility of its establishment, is examined. A desirable interplay between measurement standards and documentary standards in establishing the traceability chain in particle measurements is suggested. Particle-related calibration services currently provided by our laboratory at the National Institute of Advanced Industrial Science and Technology are also described.

A limit on particle number emission from the exhaust of Euro 5/6 engines will take effect in 2011 and engine exhaust particle number concentrations are required to be measured by particle number counters that meet requirements set forth by the UN/ECE particulate measurement programme (PMP). The TSI Model 3790 engine exhaust condensation particle counter (EECPC) was developed to meet these PMP requirements. This paper describes an experimental study that evaluated the performance of the EECPC. Experimental setup and procedures for calibrating EECPCs were evaluated. It was found that the EECPC counting efficiency strongly depended on the aerosol material. Among several materials tested, the counting efficiencies were highest for poly-α-olefin and lowest for sodium chloride. Errors in the concentration measurement due to the aerosol material dependence were estimated and found to be significant. Considerations for selecting aerosol materials for EECPC calibration are discussed with regard to best match with engine testing conditions.

This review introduces the development of metal-containing pharmaceutics (metallopharmaceutics) such as anticancer agents containing platinum (Pt) and ruthenium (Ru), and superoxide dismutase (SOD) mimetic, focusing on the recent topics on antidiabetic vanadium (V) and zinc (Zn) complexes as well as antioxidative copper (Cu) and Zn complexes. From the ancient ages, people used many types of inorganic compounds to treat physical disorders or diseases. Since the modern concept of chemotherapy was achieved by Paul Ehrlich, who developed the arsenic (As)-containing compound to treat syphilis in 1910, a wide variety of metallopharmaceutics have been proposed and clinically used worldwide. This review is described for the researchers who are interested in the current states for the development of metallopharmaceutics.

We investigated the effects of divalent alkaline earth and first-row transition metal and zinc ions on α-glucosidase activityin vitro and in vivo. CuSO4 and ZnSO4 exhibited a high α-glucosidase inhibitory effect in vitro. The IC50 values of CuSO4 were 0.77 ± 0.01 (substrate; maltose) and 0.78 ± 0.01 (substrate; sucrose), and those of ZnSO4 were 5.49 ± 0.14 (substrate; maltose) and 4.70 ± 0.06 (substrate; sucrose) for yeast α-glucosidase. On the basis of Lineweaver–Burk plots, both CuSO4 and ZnSO4 exhibited different modes of inhibition against α-glucosidase. Subsequently, oral glucose and sucrose tolerance tests (OGTT and OSTT) were performed on non-diabetic ddY mice to examine the effect of the metal ions on their blood glucose levels. As a result of single oral administration of CuSO4 in non-diabetic ddY mice, a significant and potent lowering of the blood glycemic response toward disaccharide, sucrose, ingestion was observed at 45 min after doses of 0.08 and 0.24 mmol kg−1 body weight. In contrast, the CuSO4 administration showed no suppression of the elevation of blood glucose levels in mice after a monosaccharide, glucose, administration. These results indicate that CuSO4 suppresses disaccharide digestion by inhibiting α-glucosidase activity in the epithelium of the small intestine, suggesting that antidiabetic Cu complexes with some ligands have a similar action mechanism to that of α-glucosidase inhibitor, acarbose, currently used for clinical purposes.

The use of electrostatic classification to collect samples of aerosol nanoparticles for chemical analysis is discussed. Our technique exposes the aerosol to negative ions in a unipolar charger with subsequent mobility classification at low resolution and high sampling rate. The negative unipolar charger produces high charged fractions. The low-resolution mobility classifier enables the delivery of high mass concentrations in a well-defined mobility range. The mobility-classified particles are collected by electrostatic precipitation. We summarize experimental and computational work on the performance of the unipolar charger, and we describe the performance of the overall system when used to sample atmospheric particles. For a size distribution measured in Atlanta during a new particle formation event, calculated mass sampling rates of approximately 8 nm particles were about 150 pg/h.

Vanadyl sulfate (VOSO(4)) has been clinically tested in diabetic patients since 1995. Oral administrations of VOSO(4) improved the type 2 diabetic state with respect to plasma glucose, HbA(1c), and fructosamine levels. The development of toxicity by increasing the administration of VOSO(4) should be avoided. One method was the utilization of vanadyl complexes with coordination compounds that are low-toxic and low-molecular-weight ligands to enhance the permeation of the metal ion to lipid bilayer membrane. Over a decade we have focused on a variety of heterocyclic compounds as bidentate ligands for metal ions. Vanadyl and zinc(II) complexes of 1-substituted 3-hydroxy-2-methyl-4(1H)-pyridinethiones, 4,5,6-substituted 1-hydroxy-2(1H)-pyrimidinones, 4-(p-substituted)phenyl-3-hydroxythiazole-2(3H)-thiones, 3-hydroxypyrone, 1-alkyl- or 1-phenylalkyl-3-hydroxy-2(1H)-pyridinethiones, optically active 1-substituted 3-hydroxy-4(1H)-pyridinethiones, and 5-dialkylsulfonamido- or 5,7-bis(dialkylsulfonamido)-8-hydroxyquinolines were prepared, and their insulin-mimetic activities were evaluated in terms of IC(50) values which stand for a 50% inhibitory concentration of the free fatty acid release from isolated rat adipocytes. In this article, the relationship between the insulin-mimetic activity and the partition coefficient, the chirality, the substituent effect, molecular weight, the pK(a) value, and the coordination mode was discussed. In vivo blood glucose-lowering effects of the vanadyl complex with 1-hydroxy-4,6-dimethyl-2(1H)-pyrimidinone in streptozotocin (STZ)-induced diabetic rats and the zinc(II) complexes with 4-(p-chlorophenyl)thiazole- and 4-methylthiazole-2(3H)-thione in KK-A(y) mice were also discussed.

Vanadyl(IV) complexes are anti-diabetogenic agents. Intra-peritoneal administration of bis(allixinato)oxidovanadium(IV) [VO(alx)2] lowers high blood glucose levels in animal models of type 1 and type 2 diabetes. We have examined whether oral administration of VO(alx)2 restores impaired activation in signaling cascades related to glucose metabolism and insulin action, and alters gene expression in the skeletal muscles of streptozotocin (STZ)-induced diabetic mice (STZ-diabetic mice). We report here that daily oral administration of VO(alx)2 lowered high blood glucose levels in the STZ-diabetic mice. The oral administration of VO(alx)2 enhanced phosphorylation of Akt and glycogen synthase kinase-3β (GSK3β), located downstream of the insulin receptor cascade in the skeletal muscles. We analyzed gene expression in the muscles of the diabetic mice before and after insulin or VO(alx)2 treatment. Treating the diabetic mice with insulin or VO(alx)2 normalized the gene expression levels of 152 down-regulated and 11 up-regulated genes, and especially the up-regulation of Cyp2E1 and FoxO1 in the muscles of the diabetic mice. The insulin-mimetic effects of VO(alx)2 in the STZ-induced diabetic mice may be due to the enhancement of protein phosphorylation leading to the activation or inactivation of the transcriptional machinery. Our findings suggest that the insulin-mimetic effects of VO(alx)2 in diabetes may be due to changes in the protein phosphorylations and their gene expression levels.

Aging-associated nitro-oxidative stress causes tissue injury and activates proinflammatory pathways that play an important role in the pathogenesis of aging-associated cardiovascular dysfunction. It has been recently reported, that the copper(II)-aspirinate complex (CuAsp) exerts not only the well-known anti-inflammatory and platelet antiaggregating effects of aspirin, but, due to its superoxide dismutase mimetic activity, it acts as a potent antioxidant as well. In this study we investigated the effects of CuAsp on aging-associated myocardial and endothelial dysfunction.Aging and young rats were treated for 3 weeks with vehicle, or with CuAsp (200 mg/kg per day per os). Left ventricular pressure-volume relations were measured by using a microtip pressure-volume conductance catheter, and indexes of contractility (e.g., slope of end-systolic pressure-volume relationships [ESPVR] [E(es)], and dP/dt(max) - end-diastolic volume [EDV]) were calculated. In organ bath experiments for isometric tension with isolated aortic rings, endothelium-dependent and -independent vasorelaxation were investigated by using acetylcholine and sodium nitroprusside. When compared to the young controls, aging rats showed impaired left ventricular contractility (E(es), 0.51 +/- 0.04 vs. 2.16 +/- 0.28 mmHg/microL; dP/dt(max) - EDV, 10.71 +/- 2.02 vs. 37.23 +/- 4.18 mmHg/sec per microL; p0.05) and a marked endothelial dysfunction (maximal relaxation to acetylcholine: 66.66 +/- 1.30 vs. 87.09 +/- 1.35%; p0.05). Treatment with CuAsp resulted in reduced nitro-oxidative stress, improved cardiac function (E(es), 1.21 +/- 0.17 vs. 0.51 +/- 0.04 mmHg/microL; dP/dt(max) - EDV, 23.40 +/- 3.34 vs. 10.71 +/- 2.02 mmHg/sec per microL; p0.05) and higher vasorelaxation to acetylcholine in aging animals (94.83 +/- 0.73 vs. 66.66 +/- 1.30%; p0.05). The treatment did not influence the cardiovascular functions of young rats.Our results demonstrate that oxidative stress and inflammatory pathways contribute to the pathogenesis of cardiovascular dysfunction in the aging organism, which can be reversed by CuAsp.

In the 21st century, there has been a dramatic worldwide increase in the prevalence of metabolic syndromes, including diabetes mellitus (DM). Several synthetic pharmaceutical agents have been developed and used for the treatment of type-2 DM; however, these compounds have several problems such as side effects, hypoglycemia, and weight gain. Therefore, new drugs are required for DM therapy. We have proposed that some vanadyl complexes function as potent insulin-mimetic and antidiabetic agents in type-1 and type-2 DM animal models. In this article, we review the possible action mechanism of insulin-mimetic and antidiabetic vanadyl complexes, focusing on a recently proposed complex, bis(allixinato)oxovanadium(IV), with respect to the insulin-signaling pathway in cultured adipocytes.

The possible transformations of antidiabetic vanadium(IV) complexes in the organism are discussed. These reactions involve absorption processes in the gastrointestinal tract, transport in the blood stream and interactions with endogenous binding molecules in the glucose-metabolizing cells. Modeling studies were mostly used to determine the actual chemical form of VO(IV) complexes in various biological environments. The results suggest that decomposition and subsequent ternary complex formation with endogenous or exogenous ligands in the organism affects the absorption efficacy of the originally neutral VO(IV) compounds considerably. During transport in the blood stream, transferrin displaces the carrier ligands from the VO(IV) compounds and plays an important role in transporting VO(IV) to the cell. In the cell, vanadium undergoes redox interaction with glutathione and complexation with adenosine 5′-triphosphate (the two important cell components present in mM concentration). In vitro and in vivo biological results confirmed some of the basic findings obtained from the modeling.

A new comparison system has been constructed using a Gifford- McMahon type cryogenic refrigerator for the calibration of capsule-type standard platinum resistance thermometers (CSPRTs) below 273.16 K at the National Metrology Institute of Japan (NMIJ). The system can compare six CSPRTs at once. A gold-plated comparison block, in which CSPRTs are mounted for calibration, is made from oxygen-free high-conductivity copper. The standard uncertainties related to the temperature control of the system are estimated to be 0.04 mK. The calibrated values for CSPRTs and a rhodium–iron resistance thermometer obtained using the comparison system are in good agreement with those obtained by the direct realization of the low-temperature fixed points of the ITS-90 within the combined standard uncertainty for the calibration using the comparison system.

We previously reported new zinc complexes of allixin [bis(allixinato)zinc] and its derivative bis(thioallixin-N-methyl)zinc that demonstrated excellent antidiabetic activity in type 2 diabetic mellitus KKA(y) mice. However, the molecular mechanism of these complexes is not fully understood. Thus, we attempted to reveal the intracellular mechanism of these complexes in 3T3-L1 adipocytes. Both zinc complexes induced Akt/protein kinase B (Akt/PKB) phosphorylation. The phosphorylation of Akt/PKB enhanced glucose transporter 4 translocation to the plasma membrane; this in turn enhanced the glucose utilization in a dose- and time-dependent manner. Glucose utilization by the complexes depended on the intracellular zinc concentration. Moreover, zinc complexes suppressed the cyclic AMP dependent protein kinase mediated phosphorylation of hormone-sensitive lipase (HSL), leading to the inhibition of free fatty acid release from the 3T3-L1 adipocytes. Such responses were inhibited by wortmannin, suggesting that the suppression of HSL by zinc complexes was dependent in the phosphoinositide 3-kinase-Akt/PKB signaling cascade. On the basis of these results, we proposed that both zinc complexes activated the Akt/PKB-mediated insulin-signaling pathway and improved both glucose utilization and lipid metabolism.