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Open biomass burning is a significant source of primary air pollutants such as particulate matter (PM) and non-methane organic gases (NMOG). However, the physical and chemical atmospheric processing of these emissions during transport is poorly understood. Atmospheric transformations of biomass burning emissions have been investigated in environmental chambers, but there have been limited opportunities to investigate these transformations in the atmosphere. In this study, we deployed a suite of real-time instrumentation on a Twin Otter aircraft to sample smoke from prescribed fires in South Carolina, conducting measurements at both the source and downwind to characterize smoke evolution with atmospheric aging. Organic aerosol (OA) within the smoke plumes was quantified using an aerosol mass spectrometer (AMS); refractory black carbon (rBC) was quantified using a single-particle soot photometer, and carbon monoxide (CO) and carbon dioxide (CO2) were measured using a cavity ring-down spectrometer. During the two fires for which we were able to obtain aerosol aging data, normalized excess mixing ratios and "export factors" of conserved species (rBC, CO, CO2) suggested that changes in emissions at the source did not account for most of the differences observed in samples of increasing age. An investigation of AMS mass fragments indicated that the in-plume fractional contribution (fm/z) to OA of the primary fragment (m/z 60) decreased downwind, while the fractional contribution of the secondary fragment (m/z 44) increased. Increases in f44 are typically interpreted as indicating chemical aging of OA. Likewise, we observed an increase in the O : C elemental ratio downwind, which is usually associated with aerosol aging. However, the rapid mixing of these plumes into the background air suggests that these chemical transformations may be attributable to the different volatilities of the compounds that fragment to these m/z in the AMS. The gas–particle partitioning behavior of the bulk OA observed during the study was consistent with the predictions from a parameterization developed for open biomass burning emissions in the laboratory. Furthermore, we observed no statistically significant increase in total organic mass with atmospheric transport. Hence, our results suggest that dilution-driven evaporation likely dominated over the chemical production of secondary organic aerosol (SOA) within our smoke plumes, presumably due to the fast dilution and limited aging times (< ~ 5 h) that we could sample.

Normalized excess mixing ratios (NEMRs), also known as enhancement ratios, are a common way to characterize plumes of pollution in atmospheric research. As single-source pollutant plumes disperse in the atmosphere, they are diluted by mixing with the adjacent background air. Changes in the composition of this background air can cause large changes to the NEMR that is subsequently measured by remote-sensing, airborne, or ground-based instruments. This scenario is common when boundary layer plumes enter the free troposphere and could also impact long-range transport or plumes near the top of the troposphere. We provide a context for these issues and an example showing that neglect of this effect could lead to serious errors in data interpretation.

Within minutes after emission, rapid, complex photochemistry within a biomass burning smoke plume can cause large changes in the concentrations of ozone (O3) and organic aerosol (OA). Being able to understand and simulate this rapid chemical evolution under a wide variety of conditions is a critical part of forecasting the impact of these fires on air quality, atmospheric composition, and climate. Here we use version 2.1 of the Aerosol Simulation Program (ASP) to simulate the evolution of O3 and secondary organic aerosol (SOA) within a young biomass burning smoke plume from the Williams prescribed burn in chaparral, which was sampled over California in November 2009. We demonstrate the use of a method for simultaneously accounting for the impact of the unidentified semi-volatile to extremely low volatility organic compounds (here collectively called "SVOCs") on the formation of OA (using the Volatility Basis Set) and O3 (using the concept of mechanistic reactivity). We show that this method can successfully simulate the observations of O3, OA, PAN, NOx, and C2H4 to within measurement uncertainty using reasonable assumptions about the chemistry of the unidentified SVOCs. These assumptions were: (1) a~reaction rate constant with OH of ~10−11cm3s−1, (2) a significant fraction (~50%) of the RO2 + NO reaction resulted in fragmentation, rather than functionalization, of the parent SVOC, (3) ~1.1 molecules of O3 were formed for every molecule of SVOC that reacted, (4) ~60% of the OH that reacted with the unidentified SVOCs was regenerated as HO2, and (5) that ~50% of the NO that reacted with the SVOC peroxy radicals was lost, presumably to organic nitrate formation. Additional evidence for the fragmentation pathway is provided by the observed rate of formation of acetic acid, which is consistent with our assumed fragmentation rate. This method could provide a way for classifying different smoke plume observations in terms of the average chemistry of their SVOCs, and could be used to study how the chemistry of these compounds (and the O3 and OA they form) varies between plumes.

強誘電性液晶は電場に対して通常の液晶より高速に応答する. この性質をポリアセチレンの側鎖に導入することができれば, 液晶側鎖の自発配向性と電場応答性を利用して, 主鎖の巨視的配向や導電性の制御を高速に行うことができる. 本研究では強誘電液晶性共役系高分子を開発するため, フッ素不斉骨格をもつ光学活性な液晶基をポリアセチレンの側鎖に導入した. 液晶相の同定は偏光顕微鏡, 示差走査熱量計, およびX線回折により行った. 合成したすべてのポリマーは液晶性を示した. そのうちの二つのポリマーは昇温過程と降温過程においてキラルスメチックC (S*c) 相を示した. S*c相を示す当該ポリマーは強誘電液晶性共役系高分子になりうると期待される.

Structures, magnetic properties and read/write properties were studied for low-temperature-growth CoCrPt/Cr magnetic recording media, of which CoCrPt films were sputter-deposited under various Ar pressures. Increase of Ar pressure causes both isolation enhancement and size decrease of CoCrPt grains, which are epitaxially grown on Cr grains. Coercivity increases as Ar pressure increases upto 20–30 mTorr. With an increase of Ar pressure, fluctuation field increases more rapidly than the case when the magnetic film thickness is decreased. Consequently, an increase of Ar pressure for sputter deposition significantly decreases medium noise with a slight decrease of output signal. The highest signal-to-noise ratio of 26.4 dB for 75 kFCI recording was obtained with the Ar pressure of 30 mTorr. This fabrication technique, which requires neither a thick Cr underlayer nor a Cr underlayer deposited under high Ar pressure, is especially suitable for the media with plastic substrates.

Glycolaldehyde (GA, 2-hydroxyethanal, C2H4O2) is a semivolatile molecule of atmospheric importance, recently proposed as a precursor in the formation of aqueous-phase secondary organic aerosol (SOA). There are few methods to measure GA vapor, but infrared spectroscopy has been used successfully. Using vetted protocols we have completed the first assignment of all fundamental vibrational modes and also derived quantitative IR absorption band strengths using both neat and pressure-broadened GA vapor. Even though GA is problematic due to its propensity to both dimerize and condense, our intensities agree well with the few previously published values. Using the ν10 band Q-branch at 860.51 cm(-1), we have also determined GA mixing ratios in biomass burning plumes generated by field and laboratory burns of fuels from the southeastern and southwestern United States, including the first IR field measurements of GA in smoke. The GA emission factors were anti-correlated with modified combustion efficiency confirming release of GA from smoldering combustion. The GA emission factors (grams of GA emitted per kilogram of biomass burned on a dry mass basis) had a low dependence on fuel type consistent with the production mechanism being pyrolysis of cellulose. GA was emitted at 0.23 ± 0.13% of CO from field fires, and we calculate that it accounts for ∼18% of the aqueous-phase SOA precursors that we were able to measure.

An extensive program of experiments focused on biomass burning emissions began with a laboratory phase in which vegetative fuels commonly consumed in prescribed fires were collected in the southeastern and southwestern US and burned in a series of 71 fires at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5) emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC), organic carbon (OC), and 38 elements. The trace gas emissions were measured by an open-path Fourier transform infrared (OP-FTIR) spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS), proton-transfer ion-trap mass spectrometry (PIT-MS), negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), and gas chromatography with MS detection (GC-MS). 204 trace gas species (mostly non-methane organic compounds (NMOC)) were identified and quantified with the above instruments. Many of the 182 species quantified by the GC-MS have rarely, if ever, been measured in smoke before. An additional 153 significant peaks in the unit mass resolution mass spectra were quantified, but either could not be identified or most of the signal at that molecular mass was unaccounted for by identifiable species. In a second, "field" phase of this program, airborne and ground-based measurements were made of the emissions from prescribed fires that were mostly located in the same land management units where the fuels for the lab fires were collected. A broad variety, but smaller number of species (21 trace gas species and PM2.5) was measured on 14 fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. The field measurements of emission factors (EF) are useful both for modeling and to examine the representativeness of our lab fire EF. The lab EF/field EF ratio for the pine understory fuels was not statistically different from one, on average. However, our lab EF for "smoldering compounds" emitted from the semiarid shrubland fuels should likely be increased by a factor of ~2.7 to better represent field fires. Based on the lab/field comparison, we present emission factors for 357 pyrogenic species (including unidentified species) for 4 broad fuel types: pine understory, semiarid shrublands, coniferous canopy, and organic soil. To our knowledge this is the most comprehensive measurement of biomass burning emissions to date and it should enable improved representation of smoke composition in atmospheric models. The results support a recent estimate of global NMOC emissions from biomass burning that is much higher than widely used estimates and they provide important insights into the nature of smoke. 31–72% of the mass of gas-phase NMOC species was attributed to species that we could not identify. These unidentified species are not represented in most models, but some provision should be made for the fact that they will react in the atmosphere. In addition, the total mass of gas-phase NMOC divided by the mass of co-emitted PM2.5 averaged about three (range ~2.0–8.7). About 35–64% of the NMOC were likely semivolatile or of intermediate volatility. Thus, the gas-phase NMOC represent a large reservoir of potential precursors for secondary formation of ozone and organic aerosol. For the single lab fire in organic soil about 28% of the emitted carbon was present as gas-phase NMOC and ~72% of the mass of these NMOC was unidentified, highlighting the need to learn more about the emissions from smoldering organic soils. The mass ratio of total NMOC to "NOx as NO" ranged from 11 to 267, indicating that NOx-limited O3 production would be common in evolving biomass burning plumes. The fuel consumption per unit area was 7.0 ± 2.3 Mg ha−1 and 7.7 ± 3.7 Mg ha−1 for pine-understory and semiarid shrubland prescribed fires, respectively.

Biomass burning (BB) is the second largest source of trace gases and the largest source of primary fine carbonaceous particles in the global troposphere. Many recent BB studies have provided new emission factor (EF) measurements. This is especially true for non methane organic compounds (NMOC), which influence secondary organic aerosol (SOA) and ozone formation. New EF should improve regional to global BB emissions estimates and therefore, the input for atmospheric models. In this work we present an up-to-date, comprehensive tabulation of EF for known pyrogenic species based on measurements made in smoke that has cooled to ambient temperature, but not yet undergone significant photochemical processing. All the emission factors are converted to one standard form (g compound emitted per kg dry biomass burned) using the carbon mass balance method and they are categorized into 14 fuel or vegetation types. We compile a large number of measurements of biomass consumption per unit area for important fire types and summarize several recent estimates of global biomass consumption by the major types of biomass burning. Biomass burning terminology is defined to promote consistency. Post emission processes are discussed to provide a context for the emission factor concept within overall atmospheric chemistry and also highlight the potential for rapid changes relative to the scale of some models or remote sensing products. Recent work shows that individual biomass fires emit significantly more gas-phase NMOC than previously thought and that including additional NMOC can improve photochemical model performance. A detailed global estimate suggests that BB emits at least 400 Tg yr−1 of gas-phase NMOC, which is about 4 times larger than most previous estimates. Selected recent results (e.g. measurements of HONO and the BB tracers HCN and CH3CN) are highlighted and key areas requiring future research are briefly discussed.

The cell cycle was analyzed using double staining with an anti-bromodeoxyuridine (BrdU) monoclonal antibody and propidium iodide (PI). Changes in cell kinetics after irradiation were compared with those seen by the conventional PI-based DNA histogram method. The effect of irradiation on cell kinetics has been studied primarily by counting G2-arrested cells. By the present BrdU method, a rapid transition from G1 to S-phase was observed within 2 h of irradiation, followed by G1 block. Cells in the S-phase progressed to G2+M where they arrested, resulting in a decreased percentage of S cells (5%). Release of G1 block occurred after 8 h, and G2+M cells returned to G1 after18 h. The initial G1 arrest induced by irradiation was confirmed for the first time by the present BrdU-PI double staining.

Exposure of mammalian cells to a temperature between 42 and 44 degrees C produces multiple effects on cellular metabolism. However, none of these effects have been demonstrated to be casually related to cell death. The plasma membrane has also been suggested to be one of the targets for hyperthermia. Hyperthermia influences the membrane fluidity and membrane fluidity affects both passive diffusion and active transport process. Here, we examined the effect of hyperthermia on the transmembrane potential V-79 cells using a lopophilic probe and flow cytometry. The underlying principle on which this method is based is that a freely diffusible cation distributes itself across the membrane according with the transmembrane potential and with the concentration gradient. By these methods, we tried to find the relation between the change of surviving fraction and membrane potential. We revealed that the membrane potential becomes to be depolarized by heat treatment between 41 and 44 degrees C immediately after heat treatment. In the relationship between the change in membrane potential and cell surviving fraction, the difference between 43 and 44 degrees C was not statistically significant but between 42 and 43 degrees C was statistically significant. These results imply that the cell membrane (potassium ion channel) is one of the targets of heat treatment and that duration of depolarized condition leads to cell death.

Withaferin A, a steroidal lactone isolated from the roots of the Indian medicinal plant Withania somnifera, reduced survival of V79 cells in a dose-dependent manner. LD50 for survival was 16 microM. One-hour treatment with a non-toxic dose of 2.1 microM before irradiation significantly enhanced cell killing, giving a sensitizer enhancement ratio (SER) of 1.5 for 37% survival and 1.4 for 10% survival. SER increased with drug dose, but at higher doses the increased lethality appears to be due to two effects-- drug toxicity and radiosensitization. The drug induced a G2/M block, with a maximum accumulation of cells in G2-M phase at 4 h after treatment with 10.5 microM withaferin A in 1 h. The applicability of this drug as a radiosensitizer in cancer therapy needs to be explored.

We measured Asc.- (ascorbate radical) produced by the reaction of AscH- (ascorbic acid) with HO. or O2.- after irradiation in mouse. It is possible to measure Asc.- easily using ESR and a dialysis method in which Asc.- was collected at room temperature in the interstitial fluid through the dialysis membrane. After irradiation, Asc.- increased in both normal muscle and tumour tissues (SCC-VII) in proportion to the radiation dose. Asc.- increased after treatment with the agents H2O2 and FeCl2, while it decreased after treatment with SOD and catalase. These results suggest that the amount of HO. and O2.- produced is reflected in the Asc.- production. Also, the increase in Asc.- production when WR-2721 was administered prior to irradiation was less than for experiments in which irradiation only was performed. This method is useful for the following reasons. First, no special treatment, such as freezing of the sample, and no administration of noxious agents are necessary to measure Asc.-. Second, irradiation using a dose of only a few Gy shows an increase in production of Asc.-. Third, this method does not require removal of organs. Using this method, Asc.- can serve as an indicator of the amount of HO. and O2.- produced by irradiation in vivo.

Novel shish-kebab-type liquid crystalline (LC) polyfluorene derivatives have been synthesized to develop blue luminescent organic materials with linearly polarized dichroism. The polymers are composed of 9,9-di-n-hexylfluorene moiety linked with 2,5-bis (benzoyloxy)-1,4-phenylene one, where the latter is a shish-kebab-type mesogenic unit and the phenylene is located at a center of gravity of the mesogenic unit. The polymers were soluble in common organic solvents. They showed not only smectic LC phase, but also strong blue fluorescence. Optical properties of the polymers in film before and after annealing have been examined.

The potential modifying effects of ethanol and paraquat on lesion development in livers and lungs of male F344 rats were studied. Animals were divided into diethylnitrosamine (DEN)-initiated and non-initiated groups, subgroups of each being exposed to 10 ml 20% ethanol/kg body weight, 2.5 or 10 mg paraquat/kg body weight or a combination of 10 ml 20% ethanol/kg body weight and 2.5 or 10 mg paraquat/kg body weight, given by intragastric intubation three times a week. Controls received 10 ml saline/kg body weight. All animals were subjected to two-thirds partial hepatectomy at the end of wk 3 and killed at the end of wk 8. All five rats receiving 10 mg paraquat/kg body weight without DEN-pretreatment died before termination of the experiment, but the additional ethanol treatment saved animals: only one of five rats died. Rats administered 2.5 or 10 mg paraquat/kg body weight demonstrated lung toxicity, as evidenced by fibrosis and hyperplasia, but not when simultaneously treated with ethanol in DEN-pretreated groups. In the liver, however, evaluation of glutathione S-transferase placental form (GST-P)-positive foci did not reveal any influence of the treatments on lesion development in DEN-initiated animals. It is concluded that ethanol decreases paraquat toxicity, and that neither agent, alone or in combination, exerts any hepatocarcinogenic modification potential.

We synthesized polyaniline derivative with liquid crystalline (LC) substituent. The polymer showed smectic liquid crystallinity in heating and cooling processes. The polymer was aligned by magnetic force of 10 Tesla under LC temperature region. Polarizing optical microscopy revealed a macroscopic alignment of the polymer. The orientational behavior of the LC polyaniline was evaluated from an aspect of optical dichroism in polarized absorption spectra.

Alterations in oxygenation are known to influence directly prostaglandin (PG) production by tissues such as fetal and neonatal lung cells, and by the fetal brain. However, at the present time there is no systematic study of the effects of altered oxygen tensions on PG output by the placenta or fetal membranes, the major sites of eicosanoid generation in the rocesses leading to birth. In comparison, there is considerable evidence that fetal hypoxemia activates components of the fetal hypothalamic-pituitary-adrenal-placental (HPAP) axis, including placental peptide output, and thereby may contribute indirectly to the stimulus to elevated PG generation and myometrial contractility. In this paper we shall consider situations of reduction in oxygenation that may influence HPAP activity. These include alterations in basal partial pressure of oxygen (PaO2) with gestational age, or short-term fluctuations in PaO2 resulting from episodic contractions of the myometrium throughout pregnancy. Second, there may be short-term acute reductions in fetal PaO2, reproduced experimentally in various models of acute fetal hypoxemia. Third, there may be a chronic longer-term impairment of fetal oxygenation, contributing to intrauterine growth retardation and studied experimentally in models of placental embolism, or chronic reductions in uteroplacental blood flow.

Stereoregular configuration and higher order structure of side-chain liquid crystalline (LC) polyacetylene derivatives recently developed were investigated through X-ray diffraction (XRD) measurements. XRD analyses indicated that all of the polymers showed layered structures in the LC states to exhibit smectic A phases, which is in agreement with the results of polarizing optical microscope. We also found that the LC side-chains are alternatively located at both sides of the polyene chain, giving rise to a stereoregular sequence such as head-head-tail-tail linkage. Possible mechanisms of polymerization for LC-substituted acetylene and subsequently occurring cis-trans isomerization are proposed.

Summary form only given. Polyacetylene derivatives substituted with long side chains containing mesogen unit such as poly[5-(p-(trans-4'-n-alkylcyclohexyl)phenoxy)-1-alkyne] exhibit unique liquid crystalline behavior. Dielectric constant of PPCH803A increases stepwise at the phase transition temperature between solid and liquid crystal phases, and the stepwise change is observed at the phase transition to liquid phase. Unique dependences of dielectric constant and optical transmission on the magnitude and frequency of applied voltage and magnetic field have been observed. The results are interpreted in terms of orientations of side chain of mesogen unit and also polymer main chain as functions of applied voltage and magnetic field.

The promise of conducting polymers as fast response nonlinear optical materials has been recently ernphaized1-3. Polymers such as polyacetylene, polythiophene and the soluble (and processible) poly(3alkylthienylenes) contain a high density of welectrons, and they are known to exhibit photoinduced absorption and photoinduced bleaching, indicating major shifts of oscillator strength upon photoexcitation2-4. For polyacetylene, these nonlinear effects have been studied in detail in the picosecond5a-b and subpicosecond5c time regime and correlated with the photoproduction of charge carriers through fast photoconductivity measuremenkm6. The data have demonstrated ul-tra-fast response with nonlinear shifts in oscillator strength occurring at times of the order of 10−13 seconds. These resonant nonlinear optical properties are intrinsic; they originate from the nonlinearity of the self-localized photoexcitations7 which characterize this class of polymers: solitons, polarons and bipolarons4.

The title compounds (II, XVII; dichloro and dibromo derivatives) have been prepared, and some novel reactions of the compounds described.

The title compound reacts with mercuric acetate and affords various cyclization products depending on the conditions employed. These reactions are interpreted via a n,π-complexed mercurinium ion mechanism.

The promise of conducting polymers as fast response nonlinear optical materials has been recently emphasized [1,3]. Polymers such as polyacetylene, polythiophene and the soluble (and processible) poly(3-alkylthienylenes) contain a high density of x-electrons, and they are known to exhibit photoinduced absorption and photoinduced bleaching, indicating major shifts of oscillator strength upon photoexcitation [2,4]. For polyacetylene, these nonlinear effects have been studied in detail in the picosecond [5a,b] and sub-picosecond [5c] time regime and correlated with the photoproduction of charge carriers through fast photoconductivity measurements [6]. The data have demonstrated ultra-fast response with nonlinear shifts in oscillator strength occurring at times of the order of 10-13 seconds. These resonant nonlinear optical properties are intrinsic; they originate from the nonlinearity of the self-localized photoexcitations [7] which characterize this class of polymers: solitons, polarons and bipolarons [4].

We present the results of a series of third-harmonic-generation (THG) measurements on the conjugated polymer polyacetylene which probe the magnitude and the origin of the third-order nonlinear-optical susceptibility of this material. By performing reflection THG measurements relative to a silicon standard, we have unambiguously determined the magnitude of the third-order susceptibility associated with tripling the fundamental of the Nd:YAG laser to be ${\ensuremath{\chi}}_{?}^{(3)}$(3\ensuremath{\omega};\ensuremath{\omega},\ensuremath{\omega},\ensuremath{\omega}/B) =(4\ifmmode\pm\else\textpm\fi{}2)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$ esu, where ${\ensuremath{\chi}}_{?}^{(3)}$ refers to that component of the third-order susceptibility tensor with all indices parallel to the chain direction. By measuring anisotropic THG in oriented films, we have shown that this component dominates. The magntiude and anisotropy are directly compared with results obtained from single crystals of polydiacetylene-(toluene-sulfonate) measured in the same apparatus. Finally, we have measured THG in both cis-rich and trans isomers of the same sample. We found that the measured response of the cis-rich samples scales with the residual trans content of the sample; ${\ensuremath{\chi}}_{?}^{(3)}$ of the trans isomer is 15--20 times larger than that of the cis isomer. This symmetry-specific aspect of ${\ensuremath{\chi}}^{(3)}$ implies a mechanism which is sensitive to the existence of a degenerate ground state, as in trans-(CH${)}_{\mathrm{x}}$; it is consistent with the virtual generation of nonlinear solitons as a mechanism for the large measured third-order nonlinear-optical susceptibility of polyacetylene.