[A case of severe ethylene glycol poisoning treated successfully by V-V ECMO combined with blood purification].

Ethylene glycol, also known as glycol, is a common low-temperature antifreeze used in automobiles. It is a colorless, odorless, volatile, low-sweet, sticky liquid at room temperature. Ethylene glycol is easily decomposed and absorbed through the digestive tract. Toxic metabolites cause serious clinical symptoms such as central nervous system inhibition, metabolic acidosis, cardiopulmonary symptoms and renal insufficiency, and even death. Misuse and oral suicide are the main causes of ethylene glycol poisoning. This article reports a case of severe ethylene glycol poisoning admitted to the emergency department of the Affiliated Hospital of Hangzhou Normal University in December 2021. After treatment with V-V ECMO combined with blood purification, the patient was improved and discharged from hospital.

[Evaluation of tumor vascular normalization in colorectal cancer mouse mode induced by recombinant human endostatin by intravoxel incoherent motion diffusion-weighted magnetic resonance imaging].

Objective: To evaluate the feasibility of intravoxel incoherent motion diffusion-weighted magnetic resonance imaging (IVIM-DWI MRI) in the evaluation of tumor vascular normalization in a mouse model of colorectal cancer induced by recombinant human endostatin (rhES). Methods: The CT26 colorectal cancer xenograft model of BALB/c mice were established and divided into rhES group and control group, with 20 mice in each group. The mice of rhES group were intravenously injected with rhES 5 mg·kg(-1)·d(-1) once daily for 12 days, while the mice of the control group were intravenously injected with the same volume of 0.9% saline. 5 mice of rhES group and control group were randomly selected to perform IVIM-DWI MRI as following times: before treatment and four, eight, twelve days after treatment. The parameters of IVIM-DWI were recorded, including true diffusion coefficient(D), pseudo-diffusion coefficient (D(*)) and perfusion fraction (f). Meanwhile, microvessel density (MVD), pericyte coverage and tumor perfusion in tumor tissues were detected by immunofluorescence, respectively. Results: The tumor volumes of control group and rhES group before treatment were (154.42±24.65) mm(3) and (174.24±28.27)mm(3,) respectively, without statistically significant difference (P=0.440). From day 2 to day 12 after treatment, the tumor volume of rhES group was significantly smaller than that of control group (all P<0.05). There were no statistical significances of D value between the rhES group and control group before and after treatment (all P>0.05). The D(*) values of the rhES group were (10.940±2.834)×10(-3)mm(2)/s and (12.940±2.801)×10(-3)mm(2)/s in day 4 and 8 after treatment respectively, significantly higher than (6.980±1.554)×10(-3)mm(2)/s and (7.898±1.603)×10(-3)mm(2)/s of control group (P<0.05). Moreover, compared with control group, the D(*) value of rhES group was significantly lower in day 12 (6.848±1.460)×10(-3)mm(2)/s vs (9.950±2.596)×10(-3)mm(2)/s, (P<0.05). The f value of rhES group in day 8 was (0.226±0.021)%, significantly higher than (0.178±0.016)% of control group (P<0.01). The MVD of rhES group was significantly lower than that of control group (P<0.05), while the pericyte coverage and tumor perfusion of rhES group were significantly higher than those of control group in day 4 and 8 after treatment (all P<0.05). In addition, we found D(*) value of IVIM-DWI in rhES group was significantly related with MVD, pericyte coverage and tumor perfusion (r=-0.354, r=0.555, r=0.559, all P<0.05). Meanwhile, the f value in rhES group was also significantly related with MVD, pericyte coverage and tumor perfusion (r=-0.391, r=0.538, r=0.315, all P<0.05). Conclusions: IVIM-DWI MRI can effectively evaluate the vascular normalization in rhES-induced CT26 colorectal tumor.The parameters D(*) and f are closely related to intratumorally microvessel density, pericyte coverage and perfusion, which can effectively monitor the occurrence of tumor vascular normalization time.

Cardiac µ-opioid receptor contributes to opioid-induced cardioprotection in chronic heart failure.

BACKGROUND: The therapeutic potential of cardiac µ-opioid receptors in ischaemia-reperfusion (I/R) injury during opioid-modulating diseases, such as heart failure, is unknown. We aimed to explore the changes of cardiac µ-opioid receptor expression during heart failure, and its role in opioid-induced cardioprotection. METHODS: Rats received doxorubicin (DOX) or were subjected to coronary artery ligation to induce heart failure, or received normal saline (NS) as control. Hearts from NS or DOX rats were isolated and subjected to myocardial ischaemia and reperfusion in an in vitro perfusion system. The opioid [D-Ala,2N-MePhe,4 Gly-ol]-enkephalin (DAMGO), with a high µ-opioid receptor specificity, morphine, and remifentanil were administrated before I/R with or without opioid receptor antagonists, or an extracellular signal-regulated kinase (ERK) inhibitor. RESULTS: Cardiac µ-opioid receptor mRNA concentrations were 3.2 times elevated in DOX-treated rats compared with NS rats, while cardiac µ-opioid receptor protein concentrations showed 6.1- and 3.5-fold increases in DOX-treated and post-infarcted rats, respectively. DAMGO reduced I/R-caused infarct size, expressed as the ratio of area at risk, from 0.50 (0.04) to 0.25 (0.03) in failing rat hearts, but had no effect on infarct size in control hearts. DAMGO promoted phosphorylation of ERK and glycogen synthase kinase (GSK)-3ß only in failing hearts. DAMGO-mediated cardioprotection was blocked by an ERK inhibitor. The µ-opioid receptor antagonist D-Pen-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP) prevented morphine- and remifentanil-induced cardioprotection and phosphorylation of ERK and GSK-3ß in failing hearts. In contrast, δ- and κ-opioid receptor selective antagonists were less potent than CTOP in the failing hearts. CONCLUSIONS: Cardiac µ-opioid receptors were substantially up-regulated during heart failure, which increased DAMGO-induced cardioprotection against I/R injury.

[Identification of Y-chromosomal Genetic Types for the Soldier's Remains from Huaihai Campaign].

OBJECTIVES: To identify the Y-chromosomal genetic types for the soldier's remains from Huaihai Campaign, and to offer a clue for search of their paternal relatives. METHODS: DNA of the remains were extracted by the ancient DNA extraction method. Yfiler kit was used for the multiplex amplification of 17 Y-STR loci. The haplogroups of the samples were speculated. Detailed genotyping of the selected Y-SNP was performed based on the latest Y-chromosome phylogenetic tree. Haplotype-sharing analysis was done based on the data of Y-SNP and Y-STR, the closest modern individual information to the genetic relationship of remains was gained. RESULTS: A total of 8 Y-STR haplotypes were observed on 17 Y-STR loci of 8 male individuals. Furthermore, 6 Y-SNP haplogroups were identified, which were O2a1-M95+, O1a1-P203+, O3*-M122+/M234-, D1-M15+, C3*-ST and R1a1-M17+. CONCLUSIONS: Identification of Y-chromosomal genetic types for the soldier's remains from Huaihai Campaign shows a reference value on inferring the geographical origins of old materials.

Identification and cloning of GOLDEN2-LIKE1 (GLK1), a transcription factor associated with chloroplast development in Brassica napus L.

Photosynthesis is the process by which dry matter accumulates, which affects rapeseed yield. In this study, we identified GOLDEN2-LIKE1 (GLK1), located on chromosome A07 and 59.2 kb away from the single nucleotide polymorphism marker SNP16353A07, which encodes a transcription factor associated with the rate of photosynthesis in leaves. We then identified 96 GLK1 family members from 53 species using a hidden Markov model (HMM) search and found 24 of these genes, which were derived from 17 Brassicaceae species. Phylogenetic analysis showed that 24 Brassicaceae proteins were classified into three subgroups, named the Brassica family, Adenium arabicum, and Arabidopsis. Using homologous cloning methods, we identified four BnaGLK1 copies; however, the coding sequences were shorter than the putative sequences from the reference genome, probably due to splicing errors among the reference genome sequence or different gene copies being present in the different B. napus lines. In addition, we found that BnaGLK1 genes were expressed at higher levels in leaves with more chloroplasts than were present in other leaves. Overexpression of BnaGLK1a resulted in darker leaves and siliques than observed in the control, suggesting that BnaGLK1 might promote chloroplast development to affect the rate of photosynthesis in leaves. These results will help to elucidate the mechanism of chloroplast biogenesis by GLK1 in B. napus.

Effects of ALA-PDT on HPV16-immortalized cervical epithelial cell.

Current treatments for high-grade cervical intraepithelial neoplasia (CIN) and persistent infection with high-risk human papillomavirus (HR-HPV) type are mainly surgical interventions. However, such treatments are associated with adverse side effects and pose risks for future pregnancies. In order to reduce the requirement for excisional procedures, an effective and noninvasive therapy is needed for women at reproductive age. ALA-PDT has proved to be effective in the treatment of HPV-associated disease in several clinical investigations. In this study, the anti-proliferative effect of ALA-PDT was investigated in HPV16-immortalized cervical epithelial H8 cells. CCK-8 assay was used to measure cytotoxicity in H8 cells. The IC50 of ALA-PDT on H8 cells was about 120.75 ± 1.18 µM. We have now evaluated the mechanism by which ALA-PDT induces cell death. Annexin V-FITC/PI staining showed a significant dose-dependent induction of apoptosis by ALA-PDT in H8 cells, associated with accumulation of the tumor suppressor protein p53 and the cyclin-dependent kinase inhibitor p21. Furthermore, ALA-PDT down-regulates expression of HPV E6/E7 oncogene as well as up-regulate tumor suppressor RbAp48 protein. Together, our data provides a basis for understanding and developing ALA-PDT as a cure for HPV infection-associated diseases and prevention of cervical cancer.

Expression of transforming growth factor-ß1 in neonatal rats with hyperoxia-induced bronchopulmonary dysplasia and its relationship with lung development.

The aim of this study was to detect the expression of transforming growth factor-ß1 (TGF-ß1) in neonatal rats with hyperoxia-induced bronchopulmonary dysplasia (BPD) and to explore its relationship with lung development. Forty-eight rats (2-3 days old) were randomly divided into a hyperoxia group and a control group (N = 24) which were then fed in ≥95% oxygen atmosphere and air, respectively. On the 1st, 3rd and 7th days of hyperoxia exposure, morphological changes of lung tissues were observed under an optical microscope. TGF-ß1 mRNA and protein levels in lung tissues were detected by real-time quantitative polymerase chain reaction and western blot, respectively. With increasing time of hyperoxia exposure, the hyperoxia group gradually suffered from pathological changes such as poor development of lung tissues, alveolar simplification, decrease in the number of alveoli, and hindered pulmonary microvascular development. On the 7th day of hyperoxia exposure, TGF-ß1 mRNA and protein levels (relative to b-actin) of the hyperoxia group (0.34 ± 0.19 and 0.21 ± 0.09, respectively) were significantly lower than those of the control group (0.83 ± 0.45 and 0.57 ± 0.45, respectively; P < 0.05). TGF-ß1 participates in the pathogenesis of BPD as an important regulatory factor during pulmonary vascular development.

[Nickel smelting dust exposures to NIH/3T3 cellular mitochondrial damage and L-ascorbic acid interference effect].

OBJECTIVE: To study the protection of L-ascorbic acid on mouse embryonic fibroblasts (NIH/3T3) from carcinogenic effects caused by nickel smelting smoke subjects. METHODS: The NIH/3T3 cells were divided into experimental and L-ascorbic acid in the intervention group. Plus exposure group concentration of nickel refining dusts were formulate 0.00, 25.00, 50.00, 100.00 µg/ml suspension, the intervention group on the basis of the added exposure group containing L-ascorbic acid (100 mmol/L) , contacted. Then, the cell viability was detected by MTT assay, we used Calcein-AM fluorescence probe to detect cell mitochondrial permeability transition pore (MPTP) changes, JC-1 staining to observe and detect the cell mitochondrial membrane potential (MMP) change, colorimetric quantitative to study the activity of mitochondrial respiratory chain complex Ⅰ,Ⅱ,Ⅲ,Ⅳ. RESULTS: Upon 24 h incubation, both cell relative inhibition rate, openness of MPTP were increasing enhanced by different concentrations, on the other hand, MMP and the activity of mitochondrial respiratory chain complexⅠ, Ⅱ, Ⅳ were obviously decreased, the differences were statistically significant (P<0.05) .After L-ascorbic acid intervention treatment, the results of the intervention group were lower than that of the exposure group, and the difference was statistically significant (P<0.05) , indicating the protection of L-ascorbic acid on cell mitochondrial from the nickel exposure damage. CONCLUSION: The damage effects of nickel on NIH/3T3 cell mitochondrial was significantly enhanced with the increasing concentration, and L-ascorbic acid has certain protection on cellular mitochondrial.

Screening of differentially-expressed genes in the muscles of rabbit breeds with expression profile chip.

The molecular mechanism underlying muscle development in rabbits is not well-understood. In the current study, differentially-expressed genes were scanned using an expression profile chip in New Zealand white rabbits (introduced breed) and Fujian yellow rabbits (local breed), and some of the genes were tested using reverse transcription-polymerase chain reaction. The amplification results were consistent with the microarray data. Fourteen and 13 genes involved in muscle development were identified in the dorsal longissimus and leg muscles, respectively. Myh6, Myh7, Myh7b, Myo5b, Tnnc1, Tpm3, and Acta2 were scanned in the longissimus and leg muscles. Thus, these genes may be involved in muscle fiber formation and muscle development in rabbits. This study provides a theoretical basis for improving meat quality, as well as for the future development and utilization of local meat rabbit breeds.

SKLB-287, a novel oral multikinase inhibitor of EGFR and VEGFR2, exhibits potent antitumor activity in LoVo colorectal tumor model.

Colorectal cancer (CRC) is the third common cancer and most of the chemotherapies of CRC currently used often suffer limited efficacy and large side effects. Targeted small-molecule by anti-tumor drugs are thought a promising strategy for improving the efficacy and reducing the side effects. In this investigation, we report a novel multikinase inhibitor, termed SKLB-287, which was discovered by us recently. SKLB-287 could efficiently inhibit the activation of endothelial growth factor receptor (EGFR) and vascular endothelial growth factor receptor 2 (VEGFR2). It displayed very good anti-proliferative activity against LoVo CRC cells and considerable antiangiogenic potency in transgenic zebrafish embryos. Oral administration of SKLB-287 resulted in dose-dependent suppression of tumor growth in LoVo xenograft mouse model. Immunohistochemistry was adopted to examine the in vivo anti-tumor mechanism of action of SKLB-287.

The effects of glycyrrhizin on acute pancreatitis in mice.

OBJECTIVE: This study aimed to investigate the effects of glycyrrhizin on acute pancreatitis in mice. MATERIALS AND METHODS: Sixty Balb/c mice were randomly divided into four groups as control group, model group, low dose group and high dose group (n=15). Acute pancreatitis was induced by intraperitoneal injection of Caerulein (100 µg/kg) hourly for 6 times. Mice in low dose group and high dose group received intraperitoneal administration of 15 mg/kg and 45 mg/kg glycyrrhizin respectively 4 hours before Caerulein injection. Mice in four groups were sacrificed in three equal lots at 8, 16 and 24 hours after model construction. High Mobility Group Box-1 (HMGB1) expression and serum levels of amylase, TNF-α and IL-6 were determined. The pancreatic tissues were taken for histopathologic analysis. RESULTS: Amylase, TNF-α, IL-6 and HMGB1 levels were significantly higher and pancreas lesion was severer in model group than in control group. However, Amylase, TNF-α, IL-6 and HMGB1 levels in low dose group and high dose group decreased significantly compared with model group. The pancreas lesion was also improved after administration of glycyrrhizin. CONCLUSIONS: Glycyrrhizin could decrease the levels of pro-inflammatory cytokines and downregulate the expression of HMGB1 which finally improved the pancreas lesion in mice with acute pancreatitis.

Immunoaffinity chromatography purification and ultra-high-performance liquid chromatography-tandem mass spectrometry determination of four ß-agonists in beef.

A highly selective and sensitive method was developed for the simultaneous determination of four ß-agonists (clenbuterol, salbutamol, ractopamine and terbutaline) in beef by immunoaffinity chromatography purification coupled to ultra-high-performance LC-MS/MS. The MS/MS conditions, ultra-high-performance LC mobile phase, injection solution, sample purification process and matrix effect were studied to optimise the operation conditions. The limits of detection (LODs) of the instrument for the studied ß-agonists ranged from 0.20 to 0.25 µg l(-1), and the LODs of the method for the studied ß-agonists ranged from 0.20 to 3.00 µg kg(-1) for beef. Calibration curves were constructed using a standard solution diluted with blank beef matrix. The linear ranges of the calibration curves ranged from 5 to 100 µg kg(-1) and the coefficients of determination were >0.9942 (n = 10) for all four ß-agonists. Samples spiked at 5, 10 and 50 µg kg(-1) showed recoveries >72% and RSDs <6.6%. The method is suitable for the simultaneous detection of four ß-agonists at trace levels in beef.

Diversity analysis of antagonists from rice-associated bacteria and their application in biocontrol of rice diseases.

AIMS: To understand the diversity, taxonomy and antagonistic potential of rice-associated bacteria, and to discover new bacteria for biocontrol of rice foliar pathogens. METHODS AND RESULTS: Amplified ribosomal DNA restriction analysis (ARDRA), BOX-PCR and 16S rRNA gene sequence analysis were used to identify the diversity of 203 rice-associated antagonistic bacteria. Eleven potential biocontrol bacteria were used to test their biological control of rice blast in a natural field experiment. Eleven different genera were encountered in five divisions, including Bacilli, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Deinococci. The most prominent genus in all microenvironments was Bacillus (68 x 5%). The efficacy of rice leaf blast biocontrol was 64 x 35% for strain 1Pe2, 57 x 86% for strain 2R37 and 56 x 44% for strain 1Re14. CONCLUSIONS: Biocontrol data from the field experiments demonstrated no positive correlation between antagonism, physiological characteristics and biocontrol efficacy. There was significant diversity among the rice-associated bacteria isolated from different microenvironments. The most prominent genus of all microenvironments was Bacillus. Brevibacillus brevis strain 1Pe2 and Deinococcus aquaticus strain 1Re14 have good potential for field application and commercial use. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first attempt to study the diversity and identification of rice-associated antagonistic bacteria from different microenvironments, and endophytic bacteria Deinococcus aquaticus strain 1Re14, Acidovorax sp. isolate 3Re21 and Brevibacillus brevis strain 1Pe2 are first reported as rice-associated bacteria.

High frequency occurrence of 1-OPRD variant of PRNP gene in gastric cancer cell lines and Chinese population with gastric cancer.

The prion protein gene PRNP encodes PrPc and PrPsc, causing a number of neurological disorders. Approximately 10-15% of human prion disease is inherited and more than 20 pathogenic mutations have been found. Most of the genetic alterations are point mutations, with the exception of genetic insertions of one to nine extra octapeptide repeats occurring in the important octapeptide-coding region. Our previous work showed that PrPc was overexpressed in gastric cancer. We wondered whether mutations of PrPc existed in human gastric cancer. DNA sequencing and gel electrophoresis were used to determine the possible mutation of PrPc in patients and cell lines of gastric cancer. We found that 1-OPRD (one octapeptide-repeat deletion) homozygosity or heterozygosity exists in several gastric cancer cell lines, e.g. MKN28 and KatoIII are homozygous for 1-OPRD, and SGC7901 and BGC-823 are heterozygous for 1-OPRD. The mutation frequency in tissues of gastric cancer cases is significantly higher than that in the common population (p<0.05). All positive cases in gastric cancer were found to be heterozygous for 1-OPRD. Further study of the variant may be helpful in understanding the mechanisms of occurrence and development of clinical gastric carcinoma as well as the biology of the mysterious gene PRNP.

Overexpression of PrPC and its antiapoptosis function in gastric cancer.

Cellular prion protein (PrP(C)), a glycosylphosphatidylinositol-anchored membrane protein, was found in our lab to be widely expressed in gastric cancer cell lines. In order to evaluate its biological significance in human gastric cancer, we investigated its expression in a large series of gastric tissue samples (n = 124) by immuno histochemical staining with the monoclonal antibody 3F4. Compared with normal tissues, gastric adenocarcinoma showed increased PrP(C) expression, correlated with the histopathological differentiation (according to the WHO and Lauren classifications) and tumor progression (as documented by pTNM staging). To better understand the underlying mechanism, we introduced the PrP(C) and two pairs of RNAi into the poorly differentiated gastric cancer cell line AGS and found that PrP(C) suppressed ROS and slowed down apoptosis in transfected cells. Further study proved that the apoptosis-related protein Bcl-2 was upregulated whereas p53 and Bax were downregulated in the PrP(C)-transfected cells. A reverse effect was observed in PrP(C) siRNA-transfected cells. These results strongly suggested that PrP(C) might play a role as an effective antiapoptotic protein through Bcl-2-dependent apoptotic pathways in gastric cancer cells. Further study into the mechanism of these relationships might enrich the knowledge of PrP, better our understanding of the nature of gastric carcinoma, and further develop possible strategies to block or reverse the development of gastric carcinoma.

Fluorescence from airborne microparticles: dependence on size, concentration of fluorophores, and illumination intensity.

We measured fluorescence from spherical water droplets containing tryptophan and from aggregates of bacterial cells and compared these measurements with calculations of fluorescence of dielectric spheres. The measured dependence of fluorescence on size, from both droplets and dry-particle aggregates of bacteria, is proportional to the absorption cross section calculated for homogeneous spheres containing the appropriate percentage of tryptophan. However, as the tryptophan concentration of the water droplets is increased, the measured fluorescence from droplets increases less than predicted, probably because of concentration quenching. We model the dependence of the fluorescence on input intensity by assuming that the average time between fluorescence emission events is the sum of the fluorescence lifetime and the excitation lifetime (the average time it takes for an illuminated molecule to be excited), which we calculated assuming that the intensity inside the particle is uniform. Even though the intensity inside the particles spatially varies, this assumption of uniform intensity still leads to results consistent with the measured intensity dependence.

Temporal changes of cerebral metabolites and striatal lesions in acute 3-nitropropionic acid intoxication in the rat.

To investigate the mechanisms of neuronal death in neurodegeneration, in vivo localized proton magnetic resonance spectroscopy ((1)H-MRS) and diffusion-weighted MRI (DWI) were used to evaluate temporal changes in rat striata after administration of 3-nitropropionic acid. It was found that N-acetylaspartate (NAA) reduction, with nearly simultaneous evidence of striatal lesions in DWI, was preceded by a significant and progressive increase of acetate. Shortly before the NAA levels decreased to the lowest point, acetate levels peaked and began to gradually decline toward the control levels. These results suggest that acetate increase may arise from fatty acid degradation, inhibition of succinate dehydrogenase and possible NAA hydrolysis. The elevated acetate may provide a source of acetyl group for membrane repair during excitotoxic brain injury. Magn Reson Med 44:29-34, 2000.

Asian students change their eating patterns after living in the United States.

OBJECTIVE: To collect information on changes in dietary patterns among Asian students before and after immigration to the United States. DESIGN: A questionnaire designed to collect information about background, changes in food habits, and frequency of food consumption from a 72-item food list was mailed to subjects. SUBJECTS/SETTING: Potential participants were students of local universities and junior colleges who were born in China, Taiwan, Hong Kong, Japan, or Korea and were aged 18 years or older. All subjects were required to have been residing in the United States for at least 3 months before the start of the study. Questionnaires were mailed to 120 potential participants. STATISTICAL ANALYSIS: Paired t tests were used to determine differences in eating patterns and frequency of food consumption of subjects before and after immigrating to the United States. RESULTS: Seventy-one questionnaires were returned. Because of missing information on 8 of these questionnaires, only 63 were used in the analysis, which gave a response rate of 53%. The number of students consuming only 2 meals per day increased significantly; 29 (46%) respondents skipped breakfast because of their school schedules. Despite no significant change in the frequency of snack consumption, a majority (n = 46; 73%) of the respondents were consuming more salty and sweet snack items. Subjects were eating out less often, but they were selecting more American-style fast foods when they did eat out. Significant increases were noted in consumption of fats/sweets, diary products, and fruits, and significant decreases were noted in the consumption of meat/meat alternatives and vegetables after immigration to the United States. APPLICATIONS/CONCLUSIONS: Results of this study could be useful to dietetics practitioners as they observe changes in dietary patterns of Asian immigrants. These health professionals can use this information to plan nutrition education programs for Asian groups so that they can make informed decisions in adapting to new eating patterns and make wise food choices in their new environment. It is important to help Asian immigrants retain healthful food habits from their original country and to encourage them to choose eating patterns of the new culture that are nutritionally sound.

Single-shot fluorescence spectra of individual micrometer-sized bioaerosols illuminated by a 351- or a 266-nm ultraviolet laser.

Reproducible fluorescence spectra of individual 2- to 5-microm -diameter biological aerosol particles excited with a single shot from a Q -switched laser (266 or 351 nm) have been obtained with highly improved signal-to-noise ratios. Critical to the advance are crossed diode-laser trigger beams, which precisely define the sample volume, and a reflecting objective, which minimizes chromatic aberration and has a large N.A. for collecting fluorescence. Several allergens (red oak, meadow oat pollen, paper mulberry pollen, and puffball spores) have different fluorescence spectra. Bacillus subtilis fluorescence spectrum deteriorates at high 266-nm incident intensity. Dry riboflavin particles illuminated with a 351-nm light exhibit a new 420-nm fluorescence peak that grows nonlinearly with laser pulse energy.

Two-dimensional angular optical scattering patterns as droplets evolve into clusters.

Remarkable changes in the two-dimensional angular optical scattering (TAOS) pattern are observed when an acoustically levitated water droplet with inclusions evolves into a dry aggregate. The emergence of polystyrene latex sphere inclusions near the droplet surface has a clear effect on the TAOS. A speckle pattern in the TAOS replaces the continuous contours associated with Mie scattering from a smooth droplet. Once the contours break up, this speckle pattern persists as the levitated droplet evaporates, making the transition from a droplet with inclusions to a dried aggregate. The initial emergence of the speckle pattern is observed for an inclusion volume fraction near 8%.