Transient variation of aerosol size distribution in an underground subway station

As the number of people using rapid transit systems (subways) continues to rise in major cities worldwide, increasing attention has been given to the indoor air quality of underground stations. This study intended to observe the change of PM distribution by size in an underground station with PSDs installed located near the main road in downtown Seoul, as well as to examine causes for the changes. The results indicate that the PM suspended in the tunnel flowed into the platform area even in a subway station where the effect of train-induced wind is blocked by installed PSDs, as this flow occurred when the PSDs were opened. The results also indicate that coarse mode particles generated by mechanical friction in the tunnel, such as that between wheels and rail, also flowed into the platform area. The PM either settled or was re-suspended according to size and whether the ventilation in the platform area was in operation or if the platform floor had been washed. The ventilation system was more effective in removing PM of smaller sizes (fine particles) while the wash-out performed after train operations had stopped reduced the suspension of coarse mode particles the next morning. Despite installation of the completely sealed PSDs, inflow of coarse mode particles from the tunnel seems unavoidable, indicating the need for measures to decrease the PM generated there to lower subway user exposure since those particles cannot be reduced by mechanical ventilation alone. This research implicate that coarse PM containing heavy metals (generated from tunnel side) proliferated especially during rush hours, during which it is very important to control those PM in order to reduce subway user exposure to this hazardous PM.

Generation of Nanoparticles from Friction between Railway Brake Disks and Pads

In this study, we measured the size distribution of particles ranging in size from 5.6 to 560 nm that were emitted between brake disks and pads under various braking conditions to observe and analyze changes to the resulting particle size distribution over braking time. A peak of 178-275 nm (200 nm peak) was observed in all braking conditions. However, the generation of spherical particles of a 10 nm range was observed only when the disk speed and brake force were above certain levels and intensified only when speed and brake force further increased. The total number concentration of ultrafine particles (no larger than 0.1 μm; PM0.1) generated was found to correlate with disk speed and brake force. Thus, the generation of nanoparticles resulting from disk speed and brake force was attributable primarily to increases in the contact surface temperature. The critical temperature for the generation of nanoparticles of a 10 nm range was found to be about 70 °C, which is the average temperature between the surface and the inside of the disk. If the speed or brake force was higher, that is, the temperature of the contact surface reached a certain level, evaporation and condensation took place. Vapor then left the friction surface, met with the air, and quickly cooled to form nanoparticles through nucleation. When the newly generated particles became highly concentrated, they grew through coagulation to form agglomerates or the vapor condensed directly onto the surface of existing particles of about 200 nm (formed by mechanical friction).

A multivariate study for characterizing particulate matter (PM(10), PM(2.5), and PM(1)) in Seoul metropolitan subway stations, Korea

Given that around eight million commuters use the Seoul Metropolitan Subway (SMS) each day, the indoor air quality (IAQ) of its stations has attracted much public attention. We have monitored the concentration of particulate matters (PMx) (i.e., PM10, PM2.5, and PM1) in six major transfer stations per minute for three weeks during the summer, autumn, and winter in 2014 and 2015. The data were analyzed to investigate the relationship between PMx concentration and multivariate environmental factors using statistical methods. The average PM concentration observed was approximately two or three times higher than outdoor PM10 concentration, showing similar temporal patterns at concourses and platforms. This implies that outdoor PM10 is the most significant factor in controlling indoor PM concentration. In addition, the station depth and number of trains passing through stations were found to be additional influences on PMx. Principal component analysis (PCA) and self-organizing map (SOM) were employed, through which we found that the number of trains influences PM concentration in the vicinity of platforms only, and PMx hotspots were determined. This study identifies the external and internal factors affecting PMx characteristics in six SMS stations, which can assist in the development of effective IAQ management plans to improve public health.

Evaluation of anti-acne properties of phloretin in vitro and in vivo

OBJECTIVE

This study aimed to investigate the anti-acne properties of phloretin in vitro and in vivo.

METHODS

Anti-microbial activity against Propionibacterium acnes (P. acnes), Propionibacterium granulosum (P. granulosum) and Staphylococcus epidermidis (S. epidermidis) were observed by the minimum inhibitory concentration (MIC) and disc diffusion methods. The anti-inflammatory effects were studied in HaCaT cells based on P. acnes-induced inflammatory mediators, including PGE2 and COX-2, examined through enzyme-linked immunosorbent assay (ELISA) and luciferase reporter gene assay. Thirty healthy subjects with whiteheads participated in the clinical study. Comedo counting, and the amount of sebum and porphyrin were measured before treatment and following 4 consecutive weeks of treatment with phloretin.

RESULTS

Phloretin showed anti-microbial activities against P. acnes, P. granulosum, S. epidermidis with the MIC of 0.5, 0.5 and 0.25 mg mL(-1) , respectively. P. acnes-induced activation of the COX-2 promoter was markedly attenuated by phloretin treatment. Consistent with these results, inhibition of PGE2 production was also observed. In 1-month, placebo-controlled trials, phloretin showed clinically and statistically significant reduction of comedo counts and sebum output level. Compared to before treatment, whiteheads, blackheads, papules, sebum output level and amount of sebum and porphyrin were significantly decreased at 4 weeks in the test group.

CONCLUSIONS

This study revealed that phloretin inhibits the growth of P. acnes, P. granulosum, and S. epidermidis. In addition, we demonstrated that phloretin attenuates COX-2 and PGE2 expression during the P. acnes-induced upregulation of inflammatory signalling. Clinical studies further suggested that treatment with formulations containing phloretin confers anti-acne benefits. Based on these results, we suggest that phloretin may be introduced as a possible acne-mitigating agent.

Identification of the sources of PM10 in a subway tunnel using positive matrix factorization

The level of particulate matter of less than 10 μm diameter (PM10) at subway platforms can be significantly reduced by installing a platform screen-door system. However, both workers and passengers might be exposed to higher PM10 levels while the cars are within the tunnel because it is a more confined environment. This study determined the PM10 levels in a subway tunnel, and identified the sources of PM10 using elemental analysis and receptor modeling. Forty-four PM10 samples were collected in the tunnel between the Gireum and Mia stations on Line 4 in metropolitan Seoul and analyzed using inductively coupled plasma-atomic emission spectrometry and ion chromatography. The major PM10 sources were identified using positive matrix factorization (PMF). The average PM10 concentration in the tunnels was 200.8 ± 22.0 μg/m3. Elemental analysis indicated that the PM10 consisted of 40.4% inorganic species, 9.1% anions, 4.9% cations, and 45.6% other materials. Iron was the most abundant element, with an average concentration of 72.5 ± 10.4 μg/m3. The PM10 sources characterized by PMF included rail, wheel, and brake wear (59.6%), soil combustion (17.0%), secondary aerosols (10.0%), electric cable wear (8.1%), and soil and road dust (5.4%). Internal sources comprising rail, wheel, brake, and electric cable wear made the greatest contribution to the PM10 (67.7%) in tunnel air. Implications: With installation of a platform screen door, PM10 levels in subway tunnels were higher than those on platforms. Tunnel PM10 levels exceeded 150 µg/m3 of the Korean standard for subway platform. Elemental analysis of PM10 in a tunnel showed that Fe was the most abundant element. Five PM10 sources in tunnel were identified by positive matrix factorization. Railroad-related sources contributed 68% of PM10 in the subway tunnel.

Long-term sustainable aluminum precursor solution for highly conductive thin films on rigid and flexible substrates

To fabricate the highly conductive Al film via a solution process, AlH3 etherates have been a unique Al source despite their chemical instability in solvents and thus lack of long-term sustainability. Herein, we suggest an innovative solution process to overcome the aforementioned drawbacks in AlH3 etherates; AlH3 aminates powder, which can be stored in low temperature surroundings and redissolved in solvents whenever it is needed. Since refrigeration of AlH3 aminates, AlH3{N(CH3)3}, was very effective to prevent its chemical degradation, Al film with excellence and uniformity in electrical and mechanical properties was successfully fabricated even by the 180-day stored AlH3{N(CH3)3} dissolved in solvents. Moreover, the applicability of long-term stored AlH3{N(CH3)3} to electronic devices was experimentally demonstrated by the successful operation of LED lamps connected to the Al pattern films on glass, PET, and paper substrates.

Vibrisseaceous fungi from the southern hemisphere, including Chlorovibrissea chilensis (Helotiales, incertaesedis) sp. nov

The discovery of Chlorovibrissea chilensis sp. nov.expands the distribution of Chlorovibrissea from Australasia to include South America. C. chilensis, phylogenetically distinct from other species in the genus, is also characterized morphologically by its ascoma with emerald green stalk and pale orange-brown head, budding paraphyses and 5-6-septate ascospores. Based on the phylogenetic analysis, the Australasian species Vibrisseaalbofusca is recombined in Chlorovibrissea, despite the fact it lacks the distinctive green pigmentation of other species in this genus. In addition, the genus Vibrissea in a strict phylogenetic sense is confirmed from the southern hemisphere for the first time; Vibrissea truncorum is reported from Chile and V. flavovirens from New Zealand.

Automatic Detection of Cow's Oestrus in Audio Surveillance System

Early detection of anomalies is an important issue in the management of group-housed livestock. In particular, failure to detect oestrus in a timely and accurate way can become a limiting factor in achieving efficient reproductive performance. Although a rich variety of methods has been introduced for the detection of oestrus, a more accurate and practical method is still required. In this paper, we propose an efficient data mining solution for the detection of oestrus, using the sound data of Korean native cows (Bos taurus coreanea). In this method, we extracted the mel frequency cepstrum coefficients from sound data with a feature dimension reduction, and use the support vector data description as an early anomaly detector. Our experimental results show that this method can be used to detect oestrus both economically (even a cheap microphone) and accurately (over 94% accuracy), either as a standalone solution or to complement known methods.

Emission characteristics of particulate matter and volatile organic compounds in cow dung combustion

Biomass fuel is used for cooking and heating, especially in developing countries. Combustion of biomass fuel can generate high levels of indoor air pollutants, including particulate matter (PM) and volatile organic compounds (VOCs). This study characterized PM and VOC emissions from cow dung combustion in a controlled experiment. Dung from grass-fed cows was dried and combusted using a dual-cone calorimeter. Heat fluxes of 10, 25, and 50 kW/m(2) were applied. The concentrations of PM and VOCs were determined using a dust spectrometer and gas chromatography/mass spectrometry, respectively. PM and VOC emission factors were much higher for the lower heat flux, implying a fire ignition stage. When the heat flux was 50 kW/m(2), the CO2 emission factor was highest and the PM and VOC emission factors were lowest. Particle concentrations were highest in the 0.23-0.3 μm size range at heat fluxes of 25 and 50 kW/m(2). Various toxic VOCs, including acetone, methyl ethyl ketone, benzene, and toluene, were detected at high concentrations. Although PM and VOC emission factors at 50 kW/m(2) were lower, they were high enough to cause extremely high indoor air pollution. The characteristics of PM and VOC emissions from cow dung combustion indicated potential health effects of indoor air pollution in developing countries.

Optical imaging of cell death in traumatic brain injury using a heat shock protein-90 alkylator

Traumatic brain injury is a major public health concern and is characterised by both apoptotic and necrotic cell death in the lesion. Anatomical imaging is usually used to assess traumatic brain injuries and there is a need for imaging modalities that provide complementary cellular information. We sought to non-invasively image cell death in a mouse model of traumatic brain injury using a near-infrared fluorescent conjugate of a synthetic heat shock protein-90 alkylator, 4-(N-(S-glutathionylacetyl) amino) phenylarsonous acid (GSAO). GSAO labels both apoptotic and necrotic cells coincident with loss of plasma membrane integrity. The optical GSAO specifically labelled apoptotic and necrotic cells in culture and did not accumulate in healthy organs or tissues in the living mouse body. The conjugate is a very effective imager of cell death in brain lesions. The optical GSAO was detected by fluorescence intensity and GSAO bound to dying/dead cells was detected from prolongation of the fluorescence lifetime. An optimal signal-to-background ratio was achieved as early as 3 h after injection of the probe and the signal intensity positively correlated with both lesion size and probe concentration. This optical GSAO offers a convenient and robust means to non-invasively image apoptotic and necrotic cell death in brain and other lesions.

Somatic gonad sheath cells and Eph receptor signaling promote germ-cell death in C. elegans

Programmed cell death eliminates unwanted cells during normal development and physiological homeostasis. While cell interactions can influence apoptosis as they do other types of cell fate, outside of the adaptive immune system little is known about the intercellular cues that actively promote cell death in healthy cells. We used the Caenorhabditis elegans germline as a model to investigate the extrinsic regulators of physiological apoptosis. Using genetic and cell biological methods, we show that somatic gonad sheath cells, which also act as phagocytes of dying germ cells, promote death in the C. elegans germline through VAB-1/Eph receptor signaling. We report that the germline apoptosis function of VAB-1 impacts specific cell death pathways, and may act in parallel to extracellular signal-regulated kinase MAPK signaling. This work defines a non-autonomous, pro-apoptotic signaling for efficient physiological cell death, and highlights the dynamic nature of intercellular communication between dying cells and the phagocytes that remove them.

SU-E-T-175: A Study on Design and Fabrication of 25 * 25 cm2 Beam Monitor for Scanning Carbon Beam

PURPOSE

The KHIMA is developing a superconducting cyclotron of 430 MeV/u for carbon therapy. In order to verify the irradiated beam dose and position, detectors have been developed. The detector has a considered in the active area of 25*25cm² to cover the entire beam scanning area. To minimize the loss of data during beam irradiation, a fast data acquisition system was required.

METHODS

A PPIC type was adopted. To measure the beam position and profile, the electrode of PPIC was designed to have a strip pattern. The PCB technique was applied to large area with thin FR-4 plate of electrodes. The chamber has a strip interval of 1.7mm. He was used as the filling gas in order to reduce the ion collection time. Output signal from the detector connected to the two charge integrators was transferred every 10us. The signal can be stored temporarily in memory of FPGA through one of 2 integrators.

RESULTS

The fabricated large electrode plates did not show any deformation on their shape. Depending on the beam position, the amount of dose from the ion chamber will be measured. For fast data acquisition, the DAQ board was fabricated by using 2 charge integrators and the FPGA. The obtained data from the ion chamber was displaced on the PC screen every 10us. The fluence map of a single layer will be shown on the PC screen at the end of beam irradiation on the layer. The output data from the profile monitor will be compared with Gafchromic Film results.

CONCLUSIONS

PCB method for active area of thin electrodes was used in the strip pattern. To reduce the loss of data during irradiation, 2 charge integrators are used alternately. The response of the readout data was set 1 0us. The beam tests will be performed with the MC-50 Cyclotron.

The effects of operating conditions on particulate matter exhaust from diesel locomotive engines

Numerous reports have shown that fine particulates threaten human health. Since their health impact is associated with both mass and number concentrations, it is necessary to evaluate the emission standards for particulate mass accordingly. This study examined the particulate matter characteristics of diesel locomotive engine exhaust at various engine ratings. Diesel engine exhaust was collected via a dilution tunnel and the concentration and size distribution of fine particles were measured by a scanning mobility particle sizer. Exhaust gasses were measured simultaneously by a stack sampler. The maximum carbon monoxide emission was reached at 59% of the maximum rating, after which emissions decreased. The particle count median diameter increased with the engine rating, until a maximum was reached at 40% of the maximum rating. Most exhaust particles were nanoparticles with the nuclei mode range, a particle diameter (D(P))<50 nm. The increase in particles with the accumulation mode range, 50<D(P)<1000 nm, led to a mass concentration increase and number concentration reduction. The count median diameter was within the nuclei mode range at lower engine ratings, and within the accumulation mode range at higher engine ratings. Since diesel engines mainly generate fine particles, exhaust particle mass and size distribution should be considered in emission regulations.

Two new pathogenic ascomycetes in Guignardia and Rosenscheldiella on New Zealand's pygmy mistletoes (Korthalsella: Viscaceae)

Two new pathogens, Guignardia korthalsellae and Rosenscheldiella korthalsellae, are described from New Zealand's pygmy mistletoes (Korthalsella, Viscaceae). Both form ascomata on living phylloclades with minimal disruption of the tissue. Fungal hyphae within the phylloclade are primarily intercellular. Guignardia korthalsellae disrupts a limited number of epidermal cells immediately around the erumpent ascoma, while the ascomata of Rosenscheldiellakorthalsellae develop externally on small patches of stromatic tissue that form above stomatal cavities. Rosenscheldiella is applied in a purely morphological sense. LSU sequences show that R. korthalsellae as well as another New Zealand species, Rosenscheldiella brachyglottidis, are members of the Mycosphaerellaceaesensu stricto. Genetically, Rosenscheldiella, in the sense we are using it, is polyphyletic; LSU and ITS sequences place the two New Zealand species in different clades within the Mycosphaerellaceae. Rosenscheldiella is retained for these fungi until generic relationships within the family are resolved. Whether or not the type species of Rosenscheldiella, R. styracis, is also a member of the Mycosphaerellaceae is not known, but it has a similar morphology and relationship to its host as the two New Zealand species.

First Record of Bacterial Crown Rot of Papaya (Carica papaya) Caused by an Erwinia papayae-Like Bacterium in the Kingdom of Tonga

Symptoms resembling papaya bacterial crown rot (1,3) attributed to Erwinia papayae were first observed on 'Waimanalo' and 'Solo Sunrise' papaya on the island of Tongatapu, Kingdom of Tonga in July 2009. Spreading, dark green, water-soaked lesions formed on juvenile stem tissue and developed into a foul-smelling, wet rot that destroyed large sections of the stem. Coalescing, brown, angular, marginal, and intercostal lesions killed large areas of the lamina. Elongated lesions on petioles resulted in breakage and leaf death. Symptoms on stems typically moved toward the crown with the growing point being killed or the whole crown breaking off at a canker below. Isolations at 28°C on King's medium B (KB) yielded slow-growing, raised, white, mucoid colonies that produced a conspicuous, nondiffusable blue pigment in the medium. Two-day-old suspensions (1 × 10⁸ CFU/ml) of two cultures were injected into juvenile stem tissue, petioles, and laminae of four healthy papaya seedlings of 'Solo Sunrise' with a sterile 1-ml insulin syringe. Sterile water was used as a negative control. Typical water-soaked lesions appeared at all bacterial inoculation sites on all plants within 5 days but not on controls. Pigment-producing colonies similar to those used for inoculation were reisolated from four different stem lesions. Bacteria isolated from diseased tissues were gram negative, facultative anaerobes, oxidase negative, nonfluorescent on KB, induced a hypersensitive reaction on tobacco leaves, but could not cause soft rot on potato slices. Those characteristics, combined with blue pigment production, are consistent with the bacterium E. papayae. A partial sequence of the 16S rDNA gene of ~804 bp was amplified from four Tongan isolates (ICMP18248-18251) using primers 27f and 1492r (4). Sequences of these strains were 100% identical to each other (GenBank Nos. HQ286366-HQ286369), 99 and 98% identical to the 16SrDNA sequences of E. mallotivora strains LMG2708 (Z96084.1) and DSM4565 (AJ233414.1) respectively, and 97% identical to the 16SrDNA sequence of E. papayae strain NCPPB 4294 (AY131237.1). E. mallotivora and E. papayae cause different diseases, a leaf spot on Mallotus japonicus (2) and bacterial canker on papaya, respectively. They are closely related and in the laboratory are distinguished by only very few biochemical characteristics (1). E. papayae produces a blue pigment on KB and can utilize arabinose but not mannitol. E. mallotivora does not produce a blue pigment and can utilize mannitol but not arabinose. The four Tongan strains produced a blue pigment and could utilize mannitol and arabinose. Symptoms caused by the strains isolated from Tonga are typical of those caused by E. papayae and the strains identified share most of the characteristics of E. papayae. Because the Tongan strains were able to utilize mannitol as well as arabinose and their 16S rDNA was only 97% similar to E. papayae, these strains are referred to as an E. papayae-like bacterium. The taxonomic position of these isolates will be resolved with techniques such as Multilocus Sequence Typing analysis. To our knowledge, this is the first report of this highly destructive papaya disease in the Kingdom of Tonga and of a pathogen closely related to E. papaya in the country. References: (1) L. Gardan et al. Int. J. Syst. Bacteriol. 54:107, 2004. (2) M. Goto. Int. J. Syst. Bacteriol. 26:467, 1976. (3) N. H. Maktar et al. New Dis. Rep. 17:4, 2008. (4) F. Martin-Laurent et al. Appl. Environ. Microbiol. 67:2354, 2001.

Whitening effect of alpha-bisabolol in Asian women subjects

SYNOPSIS

Although skin pigmentation, which results from the production and distribution of melanin in the epidermis, is the major physiological defence against solar irradiation, hyperpigmentation is a common and distressing problem caused by various inflammatory skin disorders, such as eczema, allergic contact dermatitis and irritant contact dermatitis. We evaluated the effects of a preparation containing alpha-bisabolol on pigmented skin of a group of subjects. The effectiveness of the active compound, alpha-bisabolol, in a base-cream preparation for the treatment of pigmented skin was tested on 28 female subjects as follows: the cream was applied once a day to the back for 8 weeks. These same women also applied a vehicle control cream to the pigmented skin. The results were evaluated by clinical and biophysical test methods. After 8 weeks of treatment of the alpha-bisabolol-containing cream, there was significant lightening effect in the pigmented skin for the majority of the subjects who tested the cream.