用液相色谱串联质谱法测定渔业水样中6种农药的含量

本文建立了一种快速检测渔业水质样本中酰胺类除草剂乙草胺、丙草胺、丁草胺、三嗪类除草剂莠去津、烟碱类杀虫剂噻虫嗪、三唑类杀菌剂苯醚甲环唑6种农药含量的液相色谱串联质谱法。采用乙腈-水-甲酸梯度洗脱、电喷雾电离方式、多反应监测模式测定考察检出限、线性范围、日内精密度及日间精密度。在三种加标浓度下,该方法的回收率为78.2%~104.7%。用液相色谱-四级杆-飞行时间质谱对疑似目标物质进行定性,用精确质量数、同位素丰度比和二级碎片解析方式等解析定性结构。该方法能够满足检测这六种农药的要求,能准确定性,自建的谱库可为渔业污染事故鉴定和水产品质量安全风险评估做支撑。     

基于YOLO v3与图结构模型的群养猪只头尾辨别方法

在利用视频监控技术对群养猪只进行自动行为监测时,对猪只准确定位并辨别其头尾位置对提高监测水平至关重要,基于此提出一种基于YOLO v3(You only look once v3)模型与图结构模型(Pictorial structure models)的猪只头尾辨别方法。首先,利用基于深度卷积神经网络的YOLO v3目标检测模型,训练猪只整体及其头部和尾部3类目标的检测器,从而在输入图像中获得猪只整体及头尾部所有的检测结果;然后,引入图结构模型,描述猪只的头尾结构特征,对每个猪只整体检测矩形框内的头尾部位组合计算匹配得分,选择最优的部位组合方式;对部分部位漏检的情况,采取阈值分割与前景椭圆拟合的方法,根据椭圆长轴推理出缺失部位。在实际猪场环境下,通过俯拍获得猪舍监控视频,建立了图像数据集,并进行了检测实验。实验结果表明,与直接利用YOLO v3模型相比,本文方法对头尾定位的精确率和召回率均有一定提高。本文方法对猪只头尾辨别精确率达到96.22%,与其他方法相比具有明显优势。     

马铃薯AP2/ERF转录因子的克隆及植物表达载体构建

AP2/ERF基因家族转录因子普遍存在于植物中,参与植物体内的各种生物学过程,包括植物的生长发育、生物和非生物胁迫响应等。前期转录组测序的结果发现马铃薯‘加湘1号’一个AP2/ERF家族基因(PGSC0003DMG400012154)在接种晚疫病菌(Phytophthora infestans)24 h后被显著激活。从接种P.infestans 24 h的‘加湘1号’的总RNA中通过RT-PCR获得了该基因CDS序列为885 bp,BLAST分析显示该基因编码一个295个氨基酸残基的蛋白,并且含有1个AP2/ERF结构域,是AP2/ERF转录因子家族中的ERF亚家族的一员。本研究将该基因与XcmⅠ酶切的表达载体pCXSN连接,转化大肠杆菌,通过测序挑选插入正确克隆酶切验证,并成功转化农杆菌。本研究结果为进一步研究该基因的功能提供了帮助。     

基于GIS与RS的北方防沙屏障带生态系统格局演变

研究北方防沙屏障带生态系统格局演变特征,对加强屏障带建设、改善生态环境具有重要意义。以北方防沙屏障带为研究区,根据2005、2010、2015年MODIS遥感影像,将北方防沙屏障带生态系统类型划分为森林、草地、湿地、农田、城镇、荒漠和裸地7类。采用空间统计、转移矩阵、景观指数分析法、PNTIL模型等方法,对北方防沙屏障带2005—2015年生态系统类型时空演变特征进行分析。结果表明,2005—2015年北方防沙屏障带生态系统整体呈稳定状态;从分屏障带看,内蒙古防沙屏障带荒漠面积明显减少,塔里木防沙屏障带森林面积迅速增加,而河西走廊防沙屏障带草地面积明显增加;从正/逆转换方向来看,屏障带内农田、城镇、荒漠及裸地生态系统正向转换率高于逆向转换率。10年间,在景观水平上,北方防沙屏障带斑块数量、斑块密度呈减少趋势;在类型水平上荒漠景观整体呈现破碎化萎缩的趋势特征,森林、草地向形状简单化的方向发展。研究表明,2005—2015年,北方防沙屏障带生态总体向好,治沙效果明显,但局部仍面临较大压力。     

Notch1 promotes renal tubulointerstitial fibrosis in renal tissues of diabetic mice by inhibiting autophagy through Akt/mTOR signaling pathway

AIM: To observe the changes of Notch1 expression and autophagy in the renal tissues of diabetic mice, and to explore the regulatory effect of Notch1 on tubulointerstitial fibrosis by inhibiting autophagy in diabetic nephro-pathy. METHODS: The mice were randomly divided into normal control group (db/m mice) and diabetes group (db/db mice), with 8 rats in each group. After 12 weeks of feeding, the mice were sacrificed and the corresponding biochemical indexes were measured. The protein expression of Notch1 in the renal tubular epithelial cells was observed by immunohistochemical staining. The protein levels of Notch1, PTEN, p-Akt (Thr308), Akt, p-mTOR (Ser2448), mTOR, LC3, P62, collagen type Ⅰ (Col-Ⅰ) and collagen type Ⅲ (Col-Ⅲ) were determined by Western blot. RESULTS: Compared with the db/m mice, the blood glucose, glycosylated hemoglobin, serum creatinine, triglyceride and total cholesterol were increased in the db/db mice (P<0.01). Renal tubular epithelial cell vacuolar degeneration, renal tubular expansion and interstitial inflammatory cell infiltration in db/db mouse renal tissues with HE staining were observed. The images of Masson staining showed collagenous fiber-like substance deposition in the glomerular capillaries and renal interstitium, and disarrangement of tubular structure in the renal tissues of db/db mice. The protein expression levels of PTEN and LC3-Ⅱ were decreased (P<0.01 or P<0.05), while the protein levels of Notch1, P62, p-mTOR (Ser2448), p-Akt (Thr308), Col-I and Col-III were increased in the db/db mice as compared with the db/m mice (P<0.01). However, no significant change of total mTOR and Akt proteins between the 2 groups was found. CONCLUSION: Notch1 protein expression was increased, PTEN expression was significantly reduced, Akt/mTOR pathway was activated, autophagy was inhibited, and fibrosis was aggravated in the renal tissues of the diabetic mice.     

Knockdown of HMGA2 gene inhibits TGF-β1-induced human embryonic lung fibroblast growth and collagen synthesis

AIM: To investigate the effects of high mobility group A2(HMGA2) gene knockdown on the cell viability, apoptosis, collagen synthesis and oxidative stress of human embryonic lung fibroblast (HELF) induced by transforming growth factor-β1 (TGF-β1). METHODS: The HELF were divided into blank group, TGF-β1 group,negative control (NC) group and HMGA2 siRNA(si-HMGA2) group. The protein levels of HMGA2, AKT and p-AKT were determined by Western blot. The cell viability and apoptotic rate was analyzed by MTT assay and flow cytometry,respectively. The mRNA expression of collagen I (COL-Ⅰ) and COL-Ⅲ was detected by RT-qPCR. DCFH-DA was used to detect the content of reactive oxygen species (ROS). RESULTS: Compared with blank group, the protein levels of HMGA2 and p-AKT, the cell viability, the mRNA expression of COL-Ⅰ and COL-Ⅲ in TGF-β1 group were significantly increased, but the apoptotic rate and ROS level were significantly decreased (P<0.05). Compared with TGF-β1 group, the protein levels of HMGA2 and p-AKT, the cell viability, the mRNA expression of COL-Ⅰ and COL-Ⅲ in si-HMGA2 group were significantly decreased, but the apoptotic rate and ROS level were significantly increased (P<0.05). CONCLUSION: Knockdown of HMGA2 gene expression decreases the viability and collagen synthesis, and promotes apoptosis and ROS production of human embryonic lung fibroblasts induced by TGF-β1. The mechanism may be related to down-regulation of PI3K/AKT signaling pathway.     

5种动物源食品中的氟虫腈及其3个代谢物残留量检测

利用QuEChERS技术结合超高效液相色谱-串联质谱的方法检测5种动物源食品(鸡肉、鸡蛋、猪肝、牛奶、猪肉)中氟虫腈及其3个代谢物残留量。样品用乙腈提取,经低温处理,多壁碳纳米管(MWCNTs)、弗罗里硅土(Florisil)和C18分散固相萃取(d-SPE)净化,外标法定量。在不同浓度的加标水平下,氟虫腈及其代谢物在5种动物源食品中的平均回收率为72.1%～113.8%,相对标准偏差RSD为1.9%～17.6%,检出限LOD在0.73～1.94μg/kg范围内,定量限LOQ在5～10μg/kg范围内。该方法具有简单、灵敏、准确等优点,适用于动物源食品中氟虫腈及其代谢物的快速筛查和定量检测。     

Cepharanthine induces autophagy via PI3K/AKT/mTOR signaling pathway in ovarian cancer SKOV3 cells

AIM: To investigate the autophagy of human ovarian cancer SKOV3 cells induced by cepharanthine and to explore its mechanism. METHODS: The effect of cepharanthine on the viability of ovarian cancer SKOV3 cells was measured by CCK-8 assay. The SKOV3 cells were treated with cepharanthine, and then the formation of autophagosome was observed with acridine orange staining under fluorescence microscope. The protein levels of LC3, AKT, p-AKT, mTOR, p-mTOR and GAPDH in the SKOV3 cells treated with cepharanthine were determined by Western blot.RESULTS: Cepharanthine significantly inhibited the viability of ovarian cancer SKOV3 cells in a dose-dependent manner (P<0.05). The number of the intracellular acidic autophagosomes with bright red fluorescence was significantly increased after cepharanthine treatment in the SKOV3 cells. The expression of LC3-Ⅱ in SKOV3 cells was significantly enhanced after cepharanthine treatment. Furthermore, treatment with cepharanthine in the SKOV3 cells also resulted in a significant down-regulation of phosphorylated form of AKT and mTOR (P<0.01), while the total protein level was not changed. Combination of cepharanthine and 3-methyladenine resulted in a substantial decrease in the cell viability compared with using cepharanthine alone.CONCLUSION: Cepharanthine significantly inhibits the growth of human ovarian cancer SKOV3 cells and induces the autophagy, which may be correlated with down-regulation of PI3K/AKT/mTOR signaling pathway.     

利用CRISPR/Ca9技术靶向编辑芥蓝BoaZDS

以芥蓝(Brassicaoleraceavar.alboglabra)为材料,以ζ–胡萝卜素脱氢酶(ζ-Carotene desaturase,ZDS)基因为目标基因,建立其CRISPR/Cas9基因组编辑体系。在BoaZDS的编码区近5′端选择靶位点,构建了CRISPR/Cas9表达载体,通过农杆菌介导的遗传转化方法获得了19个芥蓝转基因阳性植株,Sanger测序分析发现其中13株成功突变,CRISPR/Cas9载体在芥蓝上的突变效率为68.42%,且所有突变植株均表现出明显的白化表型。     

Effect of Kechuanning on airway remodeling and protein level of p-ERK1/2 in lung tissues of asthmatic rats induced by virus

AIM:To investigate the effect of Kechuanning on airway remodeling and the protein level of p-ERK1/2 in lung tissues of asthmatic rats induced by virus. METHODS:The asthmatic rat model induced by respiratory syncytial virus was established. The experimental rats were divided into normal group, asthma model group, low dose (0.33 mL/kg), middle dose (3.0 mL/kg) and high dose (10 mL/kg) of Kechuanning groups, and PD98059 (3 mg/kg) group. The airway responsiveness of the rats was measured by animal ventilator. The pathological changes of the lung tissues were observed by HE staining. PAS staining and Masson staining were used to observe goblet epithelial cells metaplasia and airway collagen deposition. The expression of matrix metalloproteinases-9 (MMP-9) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in the lung tissues of the rats was detected by immunohistochemical staining. The protein levels of ERK1/2 and p-ERK1/2 were determined by Western blot. RESULTS:Compared with model group, the airway responsiveness of the rats in middle dose and high dose of Kechuanning groups was significantly decreased (P<0.01), the injury of lung tissues was significantly decreased, the goblet epithelial cells metaplasia and airway collagen deposition were significantly reduced (P<0.01), and the expression of MMP-9 and TIMP-1 in the lung tissues was also significantly decreased (P<0.01). In addition, the protein level of p-ERK1/2 in high dose of Kechuanning group was significantly decreased compared with model group (P<0.01). CONCLUSION:Kechuanning may treat asthma by regulating the expression of p-ERK1/2 in the lung tissues and improving the airway remodeling symptoms of asthmatic rats induced by virus.