Role of electroencephalogram and oxygen saturation in the induction mechanism of arousal for obstructive sleep apnea-hypopnea syndrome patients

Arousal concomitant with obstructive sleep apnea-hypopnea syndrome (OSAHS) is known to result in sleep fragmentation and excessive daytime sleepiness. The cause of arousal is multifarious, and the mechanism is not yet clear. The aim of this study was to further research the induction mechanism of arousal by investigating the variation of electroencephalogram (EEG) and oxygen saturation (SaO₂). This study enrolled 20 subjects with a clinical diagnosis of OSAHS who underwent overnight polysomnography. Respiratory events and arousals were scored, and individuals with insufficient samples (<30) were excluded. Thus, 13 subjects mostly with severe OSAHS were analyzed in this study. The wavelet coefficients, spectral power of EEG (C4-M1 and C3-M2) before arousal or airway reopening, and the maximum desaturations of SaO₂ during respiratory events were analyzed. For most subjects, EEG (in stages N1 and N2) during respiratory events with arousals exhibited significantly lower values of wavelet coefficients and spectral power (p < 0.05). The maximum desaturations of SaO₂ during respiratory events with arousals are larger than those without among individual. In binary logistic regression analysis, the P values of EEG features and SaO₂ desaturation were both less than 0.001. Our results demonstrate that in light NREM stage, less activity in EEG during respiratory events and larger SaO₂ drop both independently were related to the occurrence of arousal. These significant differences come from major subjects based on the statistical analysis, and help supplement the induction mechanism of arousal.     

Efficient Detection of Leptosphaeria maculans from Infected Seed lots of Oilseed Rape

An efficient DNA extraction protocol and polymerase chain reaction (PCR) assay for detecting Leptosphaeria maculans from infected seed lots of oilseed rape were developed. L. maculans, the causal agent of blackleg, a damaging disease in oilseeds rape/canola worldwide, was listed as a quarantine disease by China in 2009. China imports several millions of tons of oilseeds every year. So there is a high risk that this pathogen will be introduced to China via contaminated seeds. Seed contamination is one of the most significant factors in the global spread of phytopathogens. Detection of L. maculans in infected seed lots by PCR assay is difficult due to the low level of pathogen mycelium/spores on seeds and PCR inhibitors associated with the seeds of oilseed rape. In our study, these two major obstacles were overcome by the development of a two‐step extraction protocol combined with a nested PCR. This extraction protocol (kit extraction after CTAB method) can efficiently extract high‐quality DNA for PCR. Amplification results showed that the detection threshold for conventional PCR and nested PCR was, respectively, 1 ng and 10 fg of DNA per μl in mycelia samples. On contaminated seed lots of oilseed rape, the detection threshold of conventional and nested PCR was 709 fg/μl and 709 ag/μl of DNA, respectively. The DNA extraction protocol and PCR assay developed in this study can be used for rapid and reliable detection of L. maculans from infected seeds of oilseed rape .     

Isolation and Identification of Pathogens Causing Marigold (Tagetes erecta L.) Black Spot in Beijing,China

Black spot leads to great marigold losses worldwide. The disease is characterized by black spots on leaves and stems in its early stages, and the whole plant has black rot at the advanced stage. In this report, 6 of 217 Alternaria strains isolated from lesions of marigold plants in Beijing were randomly selected. The morphological characteristics and a pathogenic tree based on two protein‐coding genes (gpd and alt a 1) indicated that Alternaria tagetica is the causal agent of marigold black spot in Beijing. All six Alternaria strains could successfully re‐infect marigold, but they could not infect carrot or zinnia by either spore spray in a greenhouse or planting experiments in the epidemic area. This is the first report of the A. tagetica pathogen being isolated from marigold in Beijing.     

First Report of Black Leaf Spot Caused by Alternaria alternata on Ramie in China

In 2012 and 2013, black leaf spot disease was observed on ramie plants in Hunan and Hubei Provinces, China. In the field, the symptoms of this disease included dark green to black big spots on leaves, often resulting in upwardly curled leaf margins. The pathogen isolates were identified as Alternaria alternata (Fr.) Keissler on the basis of morphology and sequence similarity of 99–100% to the published data for internal transcribed spacer (ITS), and glyceraldehyde‐3‐phosphate dehydrogenase (gdp). To our knowledge, this is the first report of Alternaria leaf spot of ramie in China.     

Microalgal industry in China: challenges and prospects

Over the past 15 years, China has become the major producer of microalgal biomass in the world. Spirulina (Arthrospira) is the largest microalgal product by tonnage and value, followed by Chlorella, Dunaliella, and Haematococcus, the four main microalgae grown commercially. China’s production is estimated at about two-thirds of global microalgae biomass of which roughly 90 % is sold for human consumption as human nutritional products (‘nutraceuticals’), with smaller markets in animal feeds mainly for marine aquaculture. Research is also ongoing in China, as in the rest of the world, for other high-value as well as commodity microalgal products, from pharmaceuticals to biofuels and CO₂ capture and utilization. This paper briefly reviews the main challenges and potential solutions for expanding commercial microalgae production in China and the markets for microalgae products. The Chinese Microalgae Industry Alliance (CMIA), a network founded by Chinese microalgae researchers and commercial enterprises, supports this industry by promoting improved safety and quality standards, and advancement of technologies that can innovate and increase the markets for microalgal products. Microalgae are a growing source of human nutritional products and could become a future source of sustainable commodities, from foods and feeds, to, possibly, fuels and fertilizers.     

de novo转录组学分析华南地区入侵植物五爪金龙代谢特征

为探究华南地区严重入侵植物五爪金龙(Ipomoea cairica)生物入侵的分子机制,对五爪金龙及其近缘种七爪金龙(I. digitata)和裂叶牵牛(I. nil)进行de novo转录组测序和组装,得到56551条unigenes,其中56522条得到注释,7815条GO注释,15615条COG注释,180201条KEGG数据库注释。转录组分析结果表明,五爪金龙氮代谢通路关键酶基因的表达高于对照。次生代谢关键酶(PAL、4CL、CAD、查耳酮合酶、苯基丙乙烯酮异构酶、槲皮黄3-O-甲基转移酶等)基因在五爪金龙与七爪金龙及裂叶牵牛中均得到协同性的差异表达,而这些代谢通路指导的产物合成对五爪金龙的抗逆境能力、生长、化感作用等均起关键作用。关键基因的RT-qPCR验证结果与转录组结果具有一致性。因此,这从分子生物学层面上对解释五爪金龙在华南地区的入侵机制提供了新的证据。     

小叶兜兰的果实生长和雌配子体发育

为了解濒危兰科植物小叶兜兰(Paphiopedilum barbigerum Tang et Wang)胚珠和雌配子体的发育过程,采用常规石蜡切片技术对其果实的生长动态进行了研究。结果表明,授粉后60~75 d的蒴果内种子数量迅速增加,到授粉后120 d时种子充满整个蒴果。授粉后40 d的胎座上分化形成多数由1层表皮细胞包被1列细胞的胚珠原基;授粉后60 d时位于胎座指状结构末端处紧靠表皮细胞下方的孢原细胞分化为大孢子母细胞。之后,大孢子母细胞经过减数分裂和有丝分裂最终形成成熟胚囊;授粉后135 d胚囊发育成熟,附着在胎座上的种子个体分化明显。小叶兜兰胚囊的发育类型为双孢子葱型,胚珠为倒生胚珠,薄珠心,单珠被,成熟胚囊为8核。这为小叶兜兰的生殖生物学及繁殖体系的建立提供理论依据。