Photocatalysis of 2,2',3,4,4',5'-hexachlorobiphenyl and its intermediates using various catalytical preparing methods

Four etching solutions used on support materials and two coating methods of TiO(2) were conducted to investigate the effects of catalytical preparing methods on the photocatalysis of 2,2',3,4,4',5'-hexachlorobiphenyl (PCB congener 138). The results of XRD analyses confirmed that various etching solutions used on support substrates did not influence the characteristics of titanium(IV) oxide. The XRD patterns of crystallization for the catalysts before and after purification remained unchanged. Hydrofluoric acid used as an etching solution for the support substrates provided the best adhesion stability for the catalysts that demonstrated the highest photocatalytic efficiency for congener 138. Xenon and ultraviolet lamps were used to compare the irradiation effect on photocatalysis. The shortest half-lives of congener 138 were 7.4 and 12.2 h using xenon and UV reactors, respectively. Lower chlorinated biphenyls (lower congener numbers) were identified through the continuous dechlorination of congener 138. PCB congeners 99, 87, 66, 49, 28, 17, 9, and 7 were detected as a result of dechlorination from higher chlorinated congeners to lower chlorinated congeners along with the extension of exposure times. The concentrations of chloride ion were increased with increasing exposure time through dechlorination, while the concentrations of organic chlorine of congener 138 were decreased. Meta-dechlorination was the most commonly found mechanism for the photocatalysis of PCB 138. The activation energy of the photocatalysis of congener 138 was 70.8 kJ mol(-1).

Arbuscular mycorrhizal fungi associated with the Meliaceae on Hainan island, China

Species richness, spore density, frequency of occurrence, and relative abundance of AM fungi were determined in rhizosphere soil samples from nine tropical rainforest sites on Hainan island, south China, and the arbuscular mycorrhizal (AM) status of members of the Meliaceae was examined. All 28 plant taxa investigated (25 species including two varieties of 1 species and three varieties of another) were colonized by AM fungi. The mean proportion of root length colonized was 56% (range 10-95%). Vesicles were observed in 27 and hyphal coils in 26 of the 28 plant taxa. Mycorrhizas were of the Paris-type or intermediate-type, with no Arum-type mycorrhizas observed. Species richness of AM fungi varied from 3 to 15 and spore density from 46 to 1,499 per 100 g rhizosphere soil. Of 33 AM fungal taxa in five genera isolated and identified, 18 belonged to Glomus, 9 to Acaulospora, 1 to Entrophospora, 2 to Gigaspora, and 3 to Scutellospora. Acaulospora and Glomus were the dominant genera identified. Glomus claroideum was the taxon most commonly isolated, with a frequency of occurrence of 56.5% and relative abundance of 10.4%. A positive correlation was found between percentage of root length colonization and species richness. However, there was no correlation between spore density and percentage of root length colonized by AM fungi.

Correlation of Drug-Testing Results - Immunoassay versus Gas Chromatography-Mass Spectrometry

The need for and prevalence of workplace drug-testing programs mandate the development of an effective and efficient two-step test strategy. Successful implementation of the two-step test strategy relies on the establishment of a reasonable correlation between the preliminary and the confirmatory test data and the selection of an appropriate cutoff for each test step. Correlations of test data derived form these two test steps were most commonly studied qualitatively by comparing the positive/negative test result concluded by these two test steps; however, when instrument-based immunoassays (IA) are used in the preliminary test step, the resulting "semiquantitative" and "apparent" concentration of the targeted analyte can be quantitatively correlated to the analyte concentration as determined by gas chromatography-mass spectrometry (GC-MS). Specimens selected for quantitative correlation studies should be clinical specimens with the distributions of metabolites similar to that present in test specimens; if the resulting correlation data are to be used for selecting appropriate/corresponding cutoffs for these two test steps, the concentrations of the targeted analyte in these specimens should also be within a narrow range centering on the proposed GC-MS cutoff concentration. Among the very significant number of reports correlating IA and GC-MS test data, cannabis and urine are the most common drug category and test specimen studied. The degree of correlation between IA and the GC-MS test data varies with the IA reagent manufacturers, and even with manufacture dates/lots of those supplied by the same manufacturer. The most important factors underlying the observed degree of correlation are undoubtedly the cross-reacting characteristics of the antibody and the metabolite distribution pattern of the drug of concern. Over time, specificities of IA reagents have been optimized so that the two-step test strategy can be most effectively and efficiently applied using the cutoffs mandated by workplace drug-testing programs. The nature of correlation and the selection of appropriate/corresponding cutoffs between IA and GC-MS test data derived from alternate biological matrices are yet to be fully understood and established.

Factors affecting the biodegradation of PCP by Pseudomonas mendocina NSYSU

A pentachlorophenol (PCP) degrading bacterium was isolated from PCP-contaminated soils and identified as Pseudomonas mendocina NSYSU (P. mendocina NSYSU). The main objectives of this study were to (1) clarify the factors affecting the ability and efficiency of PCP biodegradation by P. mendocina NSYSU, and (2) optimize the use of this bacterium in bioremediation of PCP. Microcosm experiments were conducted to fulfill the objectives. In batch cultures, P. mendocina NSYSU used PCP as its sole source of carbon and energy and was capable of completely degrading this compound. This was confirmed by the stoichiometric release of chloride ion. Moreover, P. mendocina NSYSU was able to mineralize a high concentration of PCP (150 mg/L). Results from the oxygen concentration experiment reveal that the growth of P. mendocina NSYSU was inhibited under low oxygen and anaerobic conditions. Results indicate that the optimal growth conditions for P. mendocina NSYSU include the following: slightly acidic (6<pH<7), aerobic, and relatively moderate ambient temperature (20 degrees C<temperature<30 degrees C) conditions. Addition of extra carbon sources (sodium acetate and glucose) could not enhance the PCP biodegradation. No PCP byproducts were detected after eight days of incubation in this study. This suggests that P. mendocina NSYSU is able to effectively biodegrade PCP and its biodegradation byproducts without the accumulation of inhibitory toxic compounds. Results from this study could be used to assist the optimization of its use in bioremediation of PCP.

Particle size and magnetic field-induced optical properties of magnetic fluid nanoparticles

Magnetite nanoparticles with diameters of 7, 9, and 12 nm have been prepared by a chemical coprecipitation method. The transmission of light through magnetic fluid containing these nanoparticles has been investigated as a function of film thickness with wavelength between 400 and 750 nm, and applied magnetic fields up to 275 Oe. The transmission threshold shifts to the lower wavelength side with decreasing magnetic fluid film thickness as well as the particle size. For a given film thickness, the transmittance increases with increasing magnetic field for films with a particle size of 7 and 9 nm, but decreases in the 12-nm film. This is attributed to the competition between the van der Waals and dipole-dipole interaction.

Utilization of the metal-cyano complex tetracyanonickelate (II) by Azotobacter vinelandii

AIMS

The ability of Azotobacter vinelandii, a N(2)-fixing bacterium, to biodegrade tetracyanonickelate (TCN) was evaluated.

METHODS AND RESULTS

The amounts of TCN were measured spectrophotometrically. Ammonia was determined colorimetrically by the indophenol method. The produced methane from TCN conversion by A. vinelandii was detected by gas chromatography. Results showed that A. vinelandii was able to biodegrade 1 mmol l(-1) of TCN. Ammonia and methane were detected during the process of TCN degradation. Effects of exogenous nitrogen sources on TCN degradation were addressed in this study. Results revealed that the addition of ammonia (1, 5 and 10 mmol l(-1)) into the reaction mixtures caused decrease of TCN degradation rate during a 24-h incubation period. This inhibition was also observed when nitrite (5 and 10 mmol l(-1)) was added, whereas TCN degradation still proceeded after the addition of nitrate at the same concentrations. Furthermore, the rate of TCN utilization was strikingly enhanced when 0.8% of glucose was added.

CONCLUSIONS

Azotobacter vinelandii can degrade 1 mmol l(-1) of TCN into ammonia and methane. However, the inhibitory effects of exogenous ammonia and nitrite on TCN degradation by this bacterium were found in this study.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report defining the capability of A. vinelandii to degrade TCN. This bacterium might have potential value in applied strategies for removing metal-cyano wastes. Furthermore, these findings would be helpful in designing a practical system inoculated with A. vinelandii for the treatment of TCN.

Cortical dysplasia associating with abnormal vasculature complicated with subdural haemorrhage

Cortical dysplasia is a neuronal migration disorder occasionally associated with anomalous draining veins. However, to our knowledge, no intracranial haemorrhage in conjunction with this association has been reported in the literature. We herein report a 7-month-old baby girl with cortical dysplasia associated with an ipsilateral cortical draining vein and complicated with subdural haemorrhage, with the diagnosis made by computed tomography and magnetic resonance imaging. This case demonstrated that patients with this condition could have an excellent prognosis even when the anomalous veins coexist with intracranial haemorrhage. We postulate that venous rupture may be the cause of this condition and further discuss the possible pathophysiology.

Detection of Burkholderia pseudomallei in rice fields with PCR-based technique

Burkholderia pseudomallei Ara- in rice fields was detected using PCR-based techniques with 16S RNA and flagella gene primer sets. The sensitivity of these PCRs was at least 1 CFU/mL of B. pseudomallei Ara- preincubated into Ashdown's medium for 6 h. B. pseudomallei Ara- DNA from watery soil were more detectable than from dry soil. The distribution of this DNA was mainly found at a depth of 300-600 mm under crop-covered fields, but not detected in the location of soil close to the land surface. The results suggest that PCR based on 16S RNA and flagella gene primer sets can be applied to investigate the presence of B. pseudomallei Ara- in contaminated soil of rice fields.

Enhanced PCE dechlorination by biobarrier systems under different redox conditions

The industrial solvent tetrachloroethylene (PCE) is among the most ubiquitous chlorinated compounds found in groundwater contamination. The objective of this study was to evaluate the (1) feasibility of enhancing PCE biodegradation using cane molasses and sludge cakes as the primary substrates under methanogenic and iron reducing conditions, and (2) potential of installation a sludge cake/cane molasses biobarrier to clean up PCE-contaminated aquifers. The biodegradability of sludge cake (from secondary wastewater treatment system) and cane molasses was tested using bioavailability experiments. Results show that biodegradable materials were released from sludge cake/cane molasses and utilized by microbial consortia. Based on the chemical oxygen demand (COD) tests, approximately 28 and 248 mg of biodegradable COD can be released from 1g of sludge cake and 1g of cane molasses under anaerobic conditions, which have the potential to convert 70 and 620 mg of PCE to ethylene (ETH), respectively. Reductive dechlorination was evaluated using microcosms containing primary substrates (sludge cake/cane molasses) and inocula (aquifer sediments). Results indicate that sludge cake and cane molasses can serve as the diffusion sources of primary substrates, and enhance the reductive dechlorination of PCE under methanogenic processes. However, results from this study were not sufficient enough to show that reductive dechlorination of PCE would occur under iron-reducing conditions. This indicates that more studies need to be performed to further evaluate the role of iron reduction on the PCE dechlorination. Results reveal that it is feasible and applicable to install a sludge cake or cane molasses biobarrier to clean up PCE contaminated aquifers. From an engineering point of view, the sludge cake/cane molasses biobarrier has the potential to become an environmentally and economically acceptable technology for PCE bioremediation.

Effects of soil pH, temperature and water content on the growth of Burkholderia pseudomallei

Optimum conditions were determined for the growth of Burkholderia pseudomallei in natural soils or waters. It grows better in paddy soil, crop-covered and fallow field than in fresh and salty water. Although the optimal temperature and pH for the growth were 37 or 42 degrees C, and 6.5 or 7.5 in an environmental-mimicking soil medium, this bacterium can still grow at 4 degrees C, which was suggested to be related with the occurrence of melioidosis in some cold areas. In soil media with water content < 15. B. pseudomallei did not grow until 60 d of incubation, suggesting that water contents of soils in which it dwelled would be one important factor in determining the growth rate.

Adsorption characteristics of benzene on biosolid adsorbent

This study selected biosolids from a petrochemical wastewater treatment plant as the raw material. The sludge was immersed in 0 to 5 mol l(-1) of ZnCl2 solutions and pyrolyzed at different temperatures. When the sludge was pyrolyzed for 30 min at temperatures of 400, 500, 600, and 700 degrees C, the corresponding surface area of the biosolid adsorbent was 46, 401, 921, and 727 m2/g, respectively. Pore size analysis indicated that the mesopore (20 to 500 A) contributed more than the macropore and micropore in the sludge pyrolytic residue. When the benzene influent concentration was 800 ppmv, the adsorption capacity ranged from 59 to 164 mg/g for different biosolid adsorbents. A larger BET surface area and smaller average pore diameter yielded a larger benzene adsorption capacity.

Remediation of PCE-contaminated aquifer by an in situ two-layer biobarrier: laboratory batch and column studies

The industrial solvent tetrachloroethylene (PCE) is among the most ubiquitous chlorinated compounds found in groundwater contamination. The objective of this study was to develop an in situ two-layer biobarrier system consisting of an organic-releasing material layer followed by an oxygen-releasing material layer. The organic-releasing material, which contained sludge cakes from a domestic wastewater treatment plant, is able to release biodegradable organics continuously. The oxygen-releasing material, which contained calcium peroxide, is able to release oxygen continuously upon contact with water. The first organic-releasing material layer was to supply organics (primary substrates) to reductively dechlorinate PCE in situ. The second oxygen-releasing material layer was to release oxygen to aerobic biodegrade or cometabolize PCE degradation byproducts from the first anaerobic layer. Batch experiments were conducted to design and identify the components of the organic and oxygen-releasing materials, and evaluate the organic substrate (presented as chemical oxygen demand (COD) equivalent) and oxygen release rates from the organic-releasing material and oxygen-releasing materials, respectively. The observed oxygen and COD release rates were approximately 0.0368 and 0.0416 mg/d/g of material, respectively. A laboratory-scale column experiment was then conducted to evaluate the feasibility of this proposed system for the bioremediation of PCE-contaminated groundwater. This system was performed using a series of continuous-flow glass columns including a soil column, an organic-releasing material column, two consecutive soil columns, and an oxygen-releasing material column, followed by two other consecutive soil columns. Anaerobic acclimated sludges were inoculated in the first four columns, and aerobic acclimated sludges were inoculated in the last three columns to provide microbial consortia for contaminant biodegradation. Simulated PCE-contaminated groundwater with a flow rate of 0.25 L/d was pumped into this system. Effluent samples from each column were analyzed for PCE and its degradation byproducts. Results show that up to 99% of PCE removal efficiency was obtained in this passive system. Thus, the biobarrier treatment scheme has the potential to be developed into an environmentally and economically acceptable remediation technology for the in situ treatment of PCE-contaminated aquifer.

Concomitant conus medullaris arteriovenous malformation and sacral dural arteriovenous fistula of the filum terminale

SUMMARY

A patient with a spinal intradural arteriovenous malformation (AVM) at the conus medullaris concomitant with a sacral dural arteriovenous fistula (AVF) of the filum terminale is reported. A 44-year-old-male presentied with bilateral leg weakness and urinary incontinence for several months. Spinal angiography demonstrated two lesions: one was spinal intradural AVM at the conus medullaris supplied by the anterior spinal artery; the other was sacral dural AVF of the filum terminale supplied by the middle sacral artery. Although multifocal spinal cord AVMs have been reported, this is the first case report of two different types of vascular malformations coexisting in one patient. The arterial supply of the dural AVF of the filum by the middle sacral artery is also first demonstrated in the literature. The patient was treated successfully by surgical approach for both lesions in the same operation.

Tuberous sclerosis complex with an unruptured intracranial aneurysm: manifestations of contiguous gene syndrome

SUMMARY

With the advancement of molecular genetics, the deletion of the TSC2/PKD1 gene at chromosome 16p13.3 has been discovered to be responsible for the tuberous sclerosis complex sharing some of the clinical manifestations of autosomal dominant adult polycystic kidney disease such as multiple renal cysts and intracranial aneurysms. The unruptured aneurysm in tuberous sclerosis complex is far beyond the meaning it has in general population. The risk of aneurysmal hemorrhage in tuberous sclerosis complex may be higher than that in autosomal dominant adult polycystic kidney disease due to the synergistic effect of gene deletion and certainly much higher than that in the general population. For such high-risk patients with intracranial aneurysms doomed to subarachnoid hemorrh age, magnetic resonance angiography plays an important role in screening and follow-up, especially more critically for patients with contiguous gene syndrome. Endovascular coil embolization should be the first choice of treatment for un ruptured intracranial aneurysms.

Analysis of the drude model in metallic films

A method, believed to be new, to simulate Drude parameters for collective oscillation of the free carriers in metallic films is proposed. Plasma resonance frequency and relaxation were simulated simultaneously from both the real and the imaginary parts of the dielectric function of a metallic film after consideration of their correlation in the Drude model. As examples, the contributions of the electrons in Ag films and of the free carriers in metallic silicide, NbSi(2) and TaSi(2), films have been studied.

Directed evolution to produce an alkalophilic variant from a Neocallimastix patriciarum xylanase

The catalytic domain of a xylanase from the anaerobic fungus Neocallimastix patriciarum was made more alkalophilic through directed evolution using error-prone PCR. Transformants expressing the alkalophilic variant xylanases produced larger clear zones when overlaid with high pH, xylan-containing agar. Eight amino acid substitutions were identified in six selected mutant xylanases. Whereas the wild-type xylanase exhibited no activity at pH 8.5, the relative and specific activities of the six mutants were higher at pH 8.5 than at pH 6.0. Seven of the eight amino acid substitutions were assembled in one enzyme (xyn-CDBFV) by site-directed mutagenesis. Some or all of the seven mutations exerted positive and possibly synergistic effects on the alkalophilicity of the enzyme. The resulting composite mutant xylanase retained a greater proportion of its activity than did the wild type at pH above 7.0, maintaining 25% of its activity at pH 9.0, and its retention of activity at acid pH was no lower than that of the wild type. The composite xylanase (xyn-CDBFV) had a relatively high specific activity of 10128 micromol glucose x min(-1) x (mg protein)(-1) at pH 6.0. It was more thermostable at 60 degrees C and alkaline tolerant at pH 10.0 than the wild-type xylanase. These properties suggest that the composite mutant xylanase is a promising and suitable candidate for paper pulp bio-bleaching.

Importance of injection solution composition for LC-MS-MS methods

For the first time, the influence of the injection solution composition on the quality of LC-MS-MS methods, in terms of column efficiency and peak shape, was systematically investigated. Various types of compounds, including polar ionic acidic, polar ionic basic and non-polar neutral compounds, were prepared in different solutions ranging from 100% water to 100% acetonitrile. Different volumes of these solutions were injected onto either C18 or silica columns connected to tandem mass spectrometry. The mobile phases consisted of acetonitrile, water, and small amounts of volatile acid or buffer. On silica columns, the influence of injection solution on the peak shape and column efficiency was straightforward. The sharpest peaks and the highest column efficiency were obtained with 100% acetonitrile as the injection solvent. On C18 columns, this type of influence was less clear due to the dual retention mechanism of the bonded phase and of the residual silanol groups. On C18 column, retention due to residual silanol groups was significant even with a mobile phase containing less than 50% acetonitrile. Poor peak shape was observed when the injection solution had a stronger eluting strength than mobile phase, particularly for early eluting peaks.

Growth inhibition of cultured smooth muscle cells by corrosion products of 316 L stainless steel wire

The potential cytotoxicity on vascular smooth muscle cells of corrosion products from 316 L stainless steel, one of most popular biomaterials of intravascular stents, has not been highlighted. In this investigation, 316 L stainless steel wires were corroded in Dulbecco's modified eagle's medium with applied constant electrochemical breakdown voltage, and the supernatant and precipitates of corrosion products were prepared as culture media. The effects of different concentrations of corrosion products on the growth of rat aortic smooth muscle cells were conducted with the [3H]-thymidine uptake test and cell cycle sorter. Both the supernatant and precipitates of corrosion products were toxic to the primary culture of smooth muscle cells. The growth inhibition was correlated well with the increased nickel ions in the corrosion products when nickel concentration was above 11.7 ppm. The corrosion products also changed cell morphology and induced cell necrosis. The cell growth inhibition occurred at the G0/G1 to S transition phase. Similar to our recent study of nitinol stent wire, the present investigation also demonstrated the cytotoxicity of corrosion products of 316 L stainless steel stent wire on smooth muscle cells, which might affect the poststenting vascular response.

Salvianolic acid B attenuates VCAM-1 and ICAM-1 expression in TNF-alpha-treated human aortic endothelial cells

Attachment to, and migration of leukocytes into the vessel wall is an early event in atherogenesis. Expression of cell adhesion molecules by the arterial endothelium may play a major role in atherosclerosis. It has been suggested that antioxidants inhibit the expression of adhesion molecules and may thus attenuate the processes leading to atherosclerosis. In the present study, the effects of a potent water-soluble antioxidant, salvianolic acid B (Sal B), and an aqueous ethanolic extract (SME), both derived from a Chinese herb, Salvia miltiorrhiza, on the expression of endothelial-leukocyte adhesion molecules by tumor necrosis factor-alpha (TNF-alpha)-treated human aortic endothelial cells (HAECs) were investigated. When pretreated with SME (50 and 100 microg/ml), the TNF-alpha-induced expression of vascular adhesion molecule-1 (VCAM-1) was notably attenuated (77.2 +/- 3.2% and 80.0 +/- 2.2%, respectively); and with Sal B (1, 2.5, 5, 10, and 20 microg/ml), 84.5 +/- 1.9%, 78.8 +/- 1.2%, 58.9 +/- 0.4%, 58.7 +/- 0.9%, and 57.4 +/- 0.3%, respectively. Dose-dependent lowering of expression of intercellular cell adhesion molecule-1 (ICAM-1) was also seen with SME or Sal B. In contrast, the expression of endothelial cell selectin (E-selectin) was not affected. SME (50 microg/ml) or Sal B (5 microg/ml) significantly reduced the binding of the human monocytic cell line, U937, to TNF-alpha-stimulated HAECs (45.7 +/- 2.5% and 55.8 +/- 1.2%, respectively). SME or Sal B significantly inhibited TNF-alpha-induced activation of nuclear factor kappa B (NF-kappaB) in HAECs (0.36- and 0.48-fold, respectively). These results demonstrate that SME and Sal B have anti-inflammatory properties and may explain their anti-atherosclerotic properties. This new mechanism of action of Sal B and SME, in addition to their previously reported inhibition of LDL, may help explain their efficacy in the treatment of atherosclerosis.

[Studies on polysaccharide alkaloids and minerals from Dendrobium moniliforme (L.) Sw]

OBJECTIVE

To explore contents of active substances in different part of Dendrobium monilifrome and the quality influenced by different drying processes.

METHOD

Contents of alkaloids and polysaccharides in upper, middle, lower-stem and root part of Dendrobium moniliforme were determined by uv-spectrophotometer method. Contents of essential trace elements were determined by ICP method.

RESULT

Contents of polysaccharides and alkaloids were highest in the upper-stem of D. montiliforme. Contents of active substances in different part of D. moniliforme were unequal. Distributions of polysaccharides and alkaloids in different parts were greatly influenced by drying procedures.

CONCLUSION

Dendrobium moniliforme has higher contents of active ingredients, such as essential tract elements, alkaloids and polysaccharides. The ideal drying process after harvesting is to be the way dried by fire at a high temperature and desiccated at a temperature of 60 degreeC.

Down-regulation of Fas-L in glioma cells by ribozyme reduces cell apoptosis, tumour-infiltrating cells, and liver damage but accelerates tumour formation in nude mice

Fas-L (CD95L, APO-1L) expresses in a variety of tumours and has been proposed to play a role in tumour formation and metastasis. The contribution of Fas-L to tumour growth, however, is not conclusive especially in systems using cells with over-expressed Fas-L. In this study we down-regulated the expression o Fas-L in human glioma cells by a hammerhead ribozyme (Fas-L(ribozyme)) targeting against Fas-L mRNA. Fas-L(ribozyme)-carrying cells exhibited slightly enhanced growth rate and less degree of spontaneous apoptosis in vitro as compared with vector controls. In nude mice, Fas-L(ribozyme)-carrying cells grew faster with lesser apoptosis, formed bigger tumour with significantly fewer infiltrating cells in the tumour area, and triggered relatively milder tumour-associated liver damage than vector controls did. Thus, down-regulation of Fas-L not only improved viability of glioma cells but also reduces local immune responses that may consequently affect tumour formation. Taken together, our findings imply that endogenous expression of Fas-L in malignant cells is not always growth promoting.

Visualization of laser-induced breakdown and ignition

Laser-induced gas breakdown and ignition of atmospheric pressure NH3/O2 mixtures are investigated. The nanosecond-pulsed, 1064-nm Nd:YAG laser is used to create the cascade-type optical breakdown. The post-breakdown plasma and ignition are studied using spectroscopic techniques that include spontaneous emission and NH planar laser-induced fluorescence (PLIF). These time-resolved two-dimensional images provide not only radiative and gas dynamic information but also the space-time loci of the temperature and transient species concentrations. The results provide an understanding of the plasma kernel dynamics and the flame development that is essential to verify on-going simulation modeling of laser-ignition.