Relationship between change of hypoxic tissue and vascular proliferation after cerebral infarction in rats

AIM: To clarify the relationship between the change of hypoxic tissue and vascular proliferation after cerebral infarction. METHODS: Rats with middle cerebral artery occlusion were randomly divided into 1.5 h ischemia-reperfusion (1.5 h IR) group and permanent ischemia (PI) group. Double staining by immunofluorescence was used to identify the hypoxic tissue and microvessels by EF5 and vWF labelings, respectively. On 3 d, 7 d and 14 d post-operation, microvessel density (MVD) and hypoxic tissue in ischemic cortex were observed. RESULTS: Hypoxic tissues existed from 3 d to 14 d post-operation in 1.5 h IR group and disappeared after 3 d in PI group. The MVD within hypoxic tissue was smaller than that around it at all observed time points (all P<0.01). With the lapse of time, MVD in ischemic cortex gradually increased both in 1.5 IR and PI groups (all P<0.01) and was bigger in 1.5 h IR group than that in PI group on 7 d and 14 d (both P<0.01). CONCLUSION: Hypoxic tissues mainly locate in areas of sparse microvessel after cerebral infarction and their duration is partially dependent on the grade of microvessel proliferation in ischemic cortex.     

Effect of transketolase-like protein 1 on proliferation of human nasopharyngeal carcinoma cells

AIM: To investigate the effect of transketolase-like protein 1 (TKTL1) on proliferation of human nasopharyngeal carcinoma cells in vitro. METHODS: The siRNA against TKTL1 mRNA was constructed and transfected into human nasopharyngeal carcinoma cells (CNE cell line). The activity of transketolase was detected before and after RNA interference.Real-time PCR was used to determine the mRNA expression of transketolase (TKT) gene family in the CNE cells.Flow cytometry and MTT test were used to detect the effect of anti-TKTL1 siRNA on cell proliferation and cell cycle in the CNE cells. RESULTS: The total transketolase activity was significantly decreased in the CNE cells transfected with siRNA TKTL1 construct compared with the cells transfected with control vector or untransfected CNE cells. No significant difference in the expression level of TKT and TKTL2 gene between the CNE cells transfected with siRNA TKTL1 construct and the cells transfected with control vector or untransfected CNE cells was observed (P>0.05). However, the expression level of TKTL1 gene was significantly downregulated in the CNE cells transfected with siRNA TKTL1 construct compared with the cells transfected with control vector.Cancer cells were arrested in G0/G1 phase, and cancer cell proliferation was significantly inhibited in the CNE cells transfected with siRNA TKTL1 construct. CONCLUSION: TKTL1 plays an important role in the total transketolase activity and cell proliferation of human nasopharyngeal carcinoma. TKTL1 may be considered as a potential target for novel anti-cancer therapy.     

Protective effect of rAAV2-NTF2 on blood-retinal barrier damage in diabetic rats

AIM: To explore the effect of rAAV2-NTF2 on the blood-retinal barrier damage in early stage diabetic retinopathy. METHODS: Retinal vasculature was observed by Evans blue. NTF2 gene was cloned into adeno-associated virus vector pSNAV. The recombinant pSNAV-NTF2 was transfected into BHK cells. After purification, high-titer rAAV2-NTF2. rAAV2-NTF2 at dose of 4 μL (titer 1.0×1012) were injected into left eyes and rAAV2-EGFP at the same does and titer were injected into the right eyes of 36 rats. After 1 month, diabetes mellitus were induced by STZ. One month after onset of diabetes, EB at a dose of 45 mg/kg was intravenously injected into the rats. Two hours later, both eyes were enucleated immediately after perfusion of 1% PFA-citric acid buffer solution. The retinas were then dissected away and placed in formamide to extract the dye. The concentration of dye was measured by spectrophotometer. RESULTS: Evans blue was contained in normal retinal vessels without leakage, with a very low level of background fluorescence. The vessels staining of diabetic rats’ retina showed increasing fluorescence, indicating the retina-blood barrier damage. Dye concentration, representing the degree of the BRB injury, was higher in retina of 1 month diabetic rats than that in normal rats (4.67 times, P<0.01), indicating retina-blood barrier break-down. Diabetic rats with rAAV2-NTF2 intravitreal injection showed decreased BRB breakdown (P<0.05). CONCLUSION: High expression of NTF-2 decreases the BRB dysfunction in DM rats.     

水芋体细胞胚胎发生及植株再生休系的建立

以水芋幼叶为外植体,应用均匀设计法筛选其最适合的胚性愈伤组织及胚性细胞复合体诱导、体细胞胚胎发育及植株再生的培养基,建立了水芋体细胞胚胎发生体系.对不同阶段培养材料的形态结构及超微结构的观察证明了水芋体细胞胚胎的发育过程.结果表明:水芋叶片胚性愈伤组织及胚性细胞复合体诱导最适宜培养基为:LS+6-BA 0.5 mg/L+2,4-D 2.0mg/L,诱导率为98.5%;体胚发育及植株再生最适宜的培养基为:LS+6-BA1.0 mg/L+NAA0.5mg/L+IAA 1.0 mg/L,体胚萌发率为96%,萌发的体胚在发育培养基上继续培养25 d后全部发育成完整植株.     

银白离褶伞驯化栽培

六个野生银白离褶伞(Lyophyllum connatum)菌株在3种不同的琼脂培养基和6种不同的培养料中的菌丝生长速度大致相似.分别以棉籽壳、玉米芯、稻草作为栽培主料,当菌丝发透培养料后在10～20 ℃变温处理(±3 ℃)条件下,六个菌株都形成子实体原基,但只有在10～15 ℃变温处理(±3 ℃)条件下五个菌株能发育出成熟的子实体.这是首次人工驯化栽培出银白离褶伞子实体.     

中小果型无籽西瓜新品种博帅的选育

博帅系湖南博达隆科技发展有限公司以9048为母本、M-2为父本杂交育成的中小果型黄瓤无籽西瓜新品种。该品种全生育期90d左右,雌花开放至果实成熟约需27d。植株生长势中强,抗病抗逆性强。果实短椭圆形,果形指数1.2。果皮浅绿底覆绿色齿条带,厚度0.9cm,硬韧,耐贮运。瓤色鲜黄,质脆爽口,纤维少,无籽性能好;中心可溶性固形物12%～13%,边部9%～9.5%。单果质量4kg左右,667m2产量2700kg左右。适应性广,全国各地均可栽培。2009年3月通过湖南省农作物品种审定委员会审定,审定编号:湘审西瓜2009002。     

食用油反式脂肪酸傅里叶红外光谱重组检测技术

以食用油、反式脂肪酸标样及矿物精油为试验材料,采用傅里叶红外光谱重组(SR-FTIR)技术检测食用油中反式脂肪酸含量,并与标准红外分析方法(SB-ATR-FTIR法)进行比较.结果表明:SR-FTIR模型反式脂肪酸含量预测值与实际加入量高度线性相关,斜率为1.02,标准差小于0.05;SR-FTIR模型的灵敏度要比标准方法模型高20余倍.     

数控螺旋锥齿轮磨齿机机床加工误差补偿

根据螺旋锥齿轮齿面的数学模型,对轮齿曲面进行了离散化处理.运用矢量运算的方法,给出了齿面离散点径矢及其法矢的计算方法.基于螺旋锥齿轮切齿计算得到的比例修正参数以及砂轮可任意修形的特点,建立了一种基于比例修正参数和砂轮参数,对机床加工误差进行补偿的方法,运用最优化算法可得到各种比例修正参数的修正倍数以及砂轮参数的改变量.通过实际的磨齿加工、齿形误差的测量以及机床调整参数的补偿,验证了机床加工误差补偿方法的正确性.     

机床误差对螺旋锥齿轮齿形的影响规

基于螺旋锥齿轮齿面分析的数学模型,采用最优化算法和一种新的计算齿形误差的方法,计算了误差齿面与理论齿面在理论齿面法线方向的齿形误差.通过引入机床调整误差和刀具参数误差,分析了各种误差对螺旋锥齿轮齿形的影响规律,以图形的方式表示了误差齿面相对于理论齿面的偏离方向以及误差值的大小,为机床的精度设计、齿形误差的修正以及指导实际加工提供了理论依据.通过实际的磨齿加工和检测对算法以及分析结果进行了验证.     

果树冠层参数实时检测系统

为了降低农药喷施环境污染和提高水果品质,实现果园果树仿形精确喷雾,建立了一套果树冠层参数的实时检测系统.该系统主要由作物识别系统、车辆姿态系统、主控单元和数据记录单元组成,采用CAN总线进行数据通信.对5棵临近的绿篱树进行了初步的靶标距离检测试验,试验重复3次.采用4个超声波传感器分时检测,拖拉机前进速度为0.3m/s,系统采样速率为5次/s.试验表明,系统能可靠地按一定的采样速率,实时检测和记录系统载体车辆位置、姿态(地面平整度)和果树靶标的距离等数据,为精确仿形喷雾提供了一个较好的喷雾控制平台.