Prenatal application of fluorescent in situ hybridization (FISH) for identification of a mosaic Y-chromosome marker,IDIC(Yp)

An amniocentesis was performed at 13.3 weeks' gestation for advanced maternal age. A mosaic sex chromosome pattern was found: of 50 cells examined, 34 had a 45,X karyotype. In 14 cells with a modal number of 46, a recognizable Y was substituted by a small non-fluorescent marker. C-banding identified the marker as an isodicentric in 12 cells. In two cells, the non-fluorescent marker appeared to be monocentric and looked like a non-fluorescent del (Yq), but could have been an isodicentric Y with inactivation of one of the centromeres. Two cells with a modal number of 47 showed two copies of the monocentric marker. Fluorescent in situ hybridization with an alpha satellite Y-specific centromeric probe confirmed the Y-chromosome origin of the markers and allowed for more accurate prenatal diagnostic information.     

Applicability of LIVE/DEAD BacLight stain with glutaraldehyde fixation for the measurement of bacterial abundance and viability in rainwater

Rainwater contains substantial bacteria and rain is an efficient pathway for the dissemination of bacteria from the atmosphere to land and water surfaces.However,quantitative information on rainwater bacteria is very limited due to the lack of a reliable method.In this study,the epifluorescence microscopy enumeration with the LIVE/DEAD BacLight Bacterial Viability Kit stain was verified to quantify the abundance of viable and non-viable bacterial cells in rainwater,with the 4',6-diamidino-2-phenylindole(DAPI) stain for the reference of total cell counts.Results showed that the total counts of bacterial cells by LIVE/DEAD BacLight staining were consistent with those by DAPI staining,and the average detection efficiency was(109 ± 29)%.The ratio of cell count with glutaraldehyde fixation to that without fixation was(106 ± 5)%on average.The bacterial concentration in negative control was usually an order of magnitude lower than that in rainwater samples.However,in case of small precipitation,the abundance in negative control could be more than that in rainwater samples.These results indicate that the enumeration with LIVE/DEAD BacLight bacterial viability assay coupled with glutaraldehyde fixation and careful negative control investigation is an approach applicable to the measurement of the concentration and viability of bacterial cells in rainwater.     

A method for the determination of rhodamine b and brilliant sulfaflavine on cotton string collectors and in a spray tank solution mixture

Abstract

A fluorescent method for the determination of rhodamine B (RhB) and brilliant sulfaflavine (BSF) dual tracers on cotton string collectors and in spray tank solutions was developed for the evaluation of the effects of adjuvants on the atmospheric drift of agricultural sprays. Both tracers on collectors were extracted with deionized water simultaneously and measured directly with a Fluorescent Specrometer by switching the maximum excitation and emission wavelengths. The linear ranges of the RhB and BSF standard curves were 0–50 and 0–10 ppb respectively. Recoveries of tracers on cotton strings ranged from 92.9% ± 1.1% to 95.1% ± 1.0% for RhB and 91.9% ± 2.8% to 103% ± 0.6% for BSF when spiked levels ranged from 0.25 to 2.5 μg per collector. The detection limit of the instrument was approximately 0.1 ppb for both tracers. The detection limits of the analytical method were approximately 0.1 ppb for RhB and 0.3 ppb for BSF when the background levels of cotton strings were subtracted. The presence of one tracer in the solution did not significantly interfere with the detection of the other tracer in the same solution. The presence of adjuvants added to the spray tank solutions did not interfere with the detection of both tracers when the adjuvants were applied at the manufacturer's maximum recommendation rates.     

US/UV联用降解荧光增白剂CBW的研究

对超声波、紫外联用技术降解荧光增白剂的反应进行研究，考察了辐射时间、超声功率、pH、H2O2投加量等因素对降解效率的影响。结果表明：荧光增白剂的降解效率受辐射时间影响较大，降解过程符合拟一级反应I提高超声波的功率可提高荧光增白剂的降解率；H2O2的添加，可使溶液中的氢氧自由基的浓度增加，从而提高了荧光增白剂的降解率。在初始浓度为40mg／L，超声功率为500w、pH为9、H2O2的添加量为30mL／L、反应120min的条件下，荧光增白剂的降解率可达95％。     

Prenatal diagnosis of Pallister–Killian syndrome: Resolution of cytogenetic ambiguity by use of fluorescent in situ hybridization

We report a case of Pallister-Killian syndrome initially diagnosed prenatally as tetrasomy 21. A 33-year-old primiparous woman was noted at 24 weeks' gestation to have moderate polyhydramnios. Ultrasonography showed diminished fetal stomach filling, hydronephrosis, and prominence of the cisterna magna. Cytogenetic analysis of cultured amniocytes was initially interpreted as mosaic tetrasomy 21: 46,XX/47,XX,+i(21q). The patient was then referred to our centre for genetic counselling. At 34 weeks' gestation, a dysmorphic infant was delivered and died within 30 min. Physical features were consistent with the Pallister-Killian syndrome. Renal, gastrointestinal, and central nervous system anomalies were found at post-mortem examination. Analysis of peripheral lymphocytes revealed 5 per cent of cells with a marker chromosome, while 92 per cent of cultured fibroblasts had this same marker. Fluorescent in situ hybridization (FISH) using an alpha-satellite probe for chromosomes 13 and 21 failed to hybridize to the marker, while a chromosome 12 centromeric probe unequivocally identified it as an i(12p). Use of FISH can provide rapid, specific prenatal diagnosis of ambiguous marker chromosomes and improve prenatal counselling.     

节能灯、白炽灯和卤钨灯全生命周期评估对比

采用全生命周期分析(LCA)的评估研究方法,全面、科学地对比分析了节能灯、白炽灯以及卤钨灯全生命周期过程中所造成的环境、资源影响,评估结果表明节能灯相对于白炽灯和卤钨灯显著降低了对环境的生态毒性影响,由于照明产品自身环境影响的特点,节能灯其突出的节电效果将显著降低白炽灯和卤钨灯对环境的各种影响。     

Effect of plant harvest on methane emission from two constructed wetlands designed for the treatment of wastewater

The emission of methane from two constructed wetlands [a free water surface flow system (FWS) and a subsurface flow system (SF)], constructed for the treatment of waste water, was evaluated at different sites inhabited by reeds (Phragmites communis), to test the effects of plant harvest. High methane emission was recorded immediately after harvesting in both wetlands. Several days after harvesting, the emission decreased in the FWS but remained high in the SF. The variation was significantly influenced by temperature, with lower emission and higher dissolved CH(4) in water occurring at lower temperatures. Both the emission and concentration of dissolved CH(4) were also influenced significantly by water quality, wetland design, level of stalk butt left above the water level, etc. The methane flux was explained on the basis of rizhospheric methanogenic and methanotrophic microbial populations. FISH analysis indicated the presence of Type A and Type B methanotrophs in both wetlands, and the methane flux was directly influenced by the quantitative variation in methanogenic and methanotrophic bacteria in both wetlands.     

The roles of garment design and scene complexity in the daytime conspicuity of high-visibility safety apparel

INTRODUCTION: This study examines the effects of high-visibility garment design on daytime pedestrian conspicuity in work zones. Factors assessed were garment color, amount of background material, pedestrian arm motion, scene complexity, and driver age. METHOD: The study was conducted in naturalistic conditions on public roads in real traffic. Drivers drove two passes on a 31-km route and indicated when they detected pedestrians outfitted in the fluorescent garments. The locations of the vehicle and the pedestrian were recorded. RESULTS: Detection distances between fluorescent yellow-green and fluorescent red-orange garments were not significantly different, nor were there any significant two-way interactions involving garment color. Pedestrians were detected at longer distances in lower complexity scenes. Arm motion significantly increased detection distances for pedestrians wearing a Class 2 vest, but had little added benefit on detection distances for pedestrians wearing a Class 2 jacket. DISCUSSION: Daytime detection distances for pedestrians wearing Class 2 or Class 3 garments are longest when the complexity of the surround is low. The more background information a driver has to search through, the longer it is likely to take the driver to locate a pedestrian--even when wearing a high-visibility garment. IMPACT ON INDUSTRY: These findings will provide information to safety garment manufacturers about characteristics of high-visibility safety garments which make them effective for daytime use.     

Degradation of a Terephthalate-containing Polyester by Thermophilic Actinomycetes and <Emphasis Type="Italic">Bacillus</Emphasis> Species Derived from Composts

We intended to find thermophilic degraders of terephthalate-containing Biomax^® films. Films in mesh bags were buried in composts (inside temperature: approximately 55–60 °C), resulting in the degradation of them in 2 weeks. Fluorescent microscopy of films recovered from composts showed that microorganisms gradually covered the surface of a film during composting. DGGE analysis of microorganisms on the composted film indicated the presence of Bacillus species as main species (approximately 80% of microbial flora) and actinomycetes (approximately 10–20%) as the second major flora. Isolation of Biomax^®-utilizing bacteria was focused on these two genera: two actinomycetes and one Bacillus species were isolated as pure best degraders from the composted polymer films, which were fragmented into small pieces. All the strains were thermophilic and identified, based on their 16S rDNA analyses. Degradation of polymer films was confirmed by (1) accelerated fragmentation of films in composts, compared with a control (no inoculum) and resultant decrease in molecular weights, (2) growth in a powdered Biomax^® medium, compared with a control without powdered Biomax^®, and (3) production of terephthalate in a powdered Biomax^® medium. In this way, we concluded that these bacteria were useful for degradation of thermostable Biomax^® products.     

Rapid field testing of mercury pollution by designed fluorescent biosensor and its cells-alginate hydrogel-based paper assay

With increasing industrial activities, mercury has been largely discharged into environment and caused serious environmental problems. The growing level of mercury pollution has become a huge threat to human health due to its significant biotoxicity. Therefore, the simple and fast means for on-site monitoring discharged mercury pollution are highly necessary to protect human beings from its pernicious effects in time. Herein, a “turn off” fluorescent biosensor (mCherry L199C) for sensing Hg²⁺ was successfully designed based on direct modification of the chromophore environment of fluorescent protein mCherry. For rapid screening and characterization, the designed variant of mCherry (mCherry L199C) was directly expressed on outer-membrane of  Escherichia coli cells by cell surface display technique. The fluorescent biosensor was characterized to have favorable response to Hg²⁺ at micromole level among other metal ions and over a broad pH range. Further, the cells of the fluorescent biosensor were encapsulated in alginate hydrogel to develop the cells-alginate hydrogel-based paper. The cells-alginate hydrogel-based paper could detect mercury pollution in 5 min with simple operation process and inexpensive equipment, and it could keep fluorescence and activity stable at 4?°C for 24 hr, which would be a high-throughput screening tool in preliminarily reporting the presence of mercury pollution in natural setting.