基于SRP模型的南雄丹霞梧桐自然保护区生态脆弱性评价

通过建立生态敏感性-生态恢复力-生态压力度（SRP）模型，利用主成分分析法确定指标权重，对南雄丹霞梧桐自然保护区进行生态脆弱性评价。结果表明:1）从生态敏感性角度，研究区高度脆弱和极度脆弱面积分别为756.50 hm²和773.58 hm²，占比之和>50%，主要集中分布于北部和中部，而主要影响要素为土壤侵蚀强度，其次为距水源距离；2）从生态恢复力角度，研究区不脆弱和轻度脆弱面积分别为777.71 hm²和676.73 hm²，占比之和>50%，主要集中分布于西部和西南部，主要影响要素为生物多样性，其次为植被覆盖度；3）从生态压力度角度，研究区不脆弱和轻度脆弱面积分别为551.33 hm²和1 205.12 hm²，占比之和>60%，主要集中分布于西部及东部，而主要影响要素为GDP密度和人口密度；4）研究区整体生态脆弱性较高，中度及以上脆弱性面积之和达到67.72%，主要集中于研究区的中部和北部，其中生态敏感性对生态脆弱性的影响最大，说明研究区整体生态脆弱性较强，应做好生态保护工作。     

一种电流模式多功能滤波器结构

提出了一种简单的电流模式多功能滤波器结构，具有一个输入端和三个输出端，可以实现低通，高通，带通，全通和陷波功能，不需要任何严格匹配关系，该结构中使用了６个ＣＣ器件，两个接地电阻和两个接地电容，结构十分简单且无源灵敏度很低。     

福建土壤对酸沉降的相对敏感性评价与区划

选择母岩、土壤类型、土地利用和降雨量 4个生态因子 ,应用半定量化方法对其进行类目划分和权重 ,综合评价了福建省土壤对酸沉降的相对敏感性 ,并应用地理信息系统进行了区划 .由于福建省风化缓慢的硅质岩所占的比例较大 ,土壤大多呈酸性至微酸性反应 ,降水丰富 ,加之针叶林面积大 ,所以全省有 60 %以上面积的土壤显示出较大的敏感性等级 (5～ 7级 )     

Sensitivity,specificity, and predictive values of reagent test strip estimations of blood urea nitrogen

Azostix-reagent-tests(R) strips (Ames, Miles, Inc., Diagnostic Division, Elkhart, IN) were used to measure blood urea nitrogen values in blood samples from 125 dogs and cats at the North Carolina State University, College of Veterinary Medicine. Results of the tests were compared with standard serum urea nitrogen results. Sensitivity, specificity, and negative predictive values were high (86.4, 90.3, and 96.5%, respectively). Positive predictive value was low, 65.5% of the dogs and cats with elevated blood urea nitrogen values were correctly classified as abnormal The test performs well when the prevalence of abnormal values is near 50%.     

Insulin induced LPL mRNA expression in THP-1 macrophage and acceleration of transferring the macrophage to foam cell

AIM:To investigate the effect of insulin on ox-LDL transferring the THP-1 cells to foam cells and influencing the LPL mRNA expression in THP-1 cells.METHODS:THP-1 cells were incubated with 50 mg/Lox-LDL and insulin at concentrations of 10 mU/L, 100 mU/L, 1 000 mU/L and 10 000 mU/L, respectively. The expression of LPL mRNA in cells was detected by RT-PCR. Lipoprotein lipase of THP-1 cells was presented by no-specific lipase staining. THP-1 cells were stained with oil red O. Accumulation of total cholesterol (TC) in THP-1 cells was determined with oxidase assay.RESULTS:In 100 mU/L、1 000 mU/L、10 000 mU/L insulin groups, LPL mRNA expression increased 2 times, the average cell perilength was longer, the percentage of positive oil red O staining cells was significant higher, the content of cholesterol in THP-1 cells was higher than in ox-LDL control (P＜0.05).CONCLUSION:Insulin accelerates transferring of THP-1 cells to foam cell with exposed to ox-LDL because LPL mRNA expression increased in the cells.     

Bcl-2 antisense oligodeoxynucleotide increases the sensitivity of HL60 and K562 cells to daunorubicin

AIM:To investigate whether the bcl-2 antisense oligonucleotide increases the sensitivity of HL60 and K562 cell lines to daunorubicin.METHODS:IC50 for HL60 and K562 was determined with MTT method, the expression levels of Bcl-2 protein were assayed by immunofluorescence using fluoresce isothiocyanate labeling. In addition, apoptosis was detected by morphological observation and flow cytometric analysis of DNA fragmentation.RESULTS:It was found that the two oligonucleotides directed against the coding region and the translation initiation of bcl-2 mRNA, combined respectively with daunorubicin, inhibited expression of bcl-2 protein, increased apoptosis in HL60 and K562 cells, and decreased IC50 of daunorubicin significantly (P＜0.05). Compared to the antisense oligonucleotide directed against the translation initiation of bcl-2 mRNA, the antisense oligonucleotide directed against the coding region showed stronger effects in the aspects of increasing the sensitivity of HL60 cells to daunorubicin (P＜0.05).CONCLUSIONS:These two antisense sequences in the translation initiation and the coding region of bcl-2 mRNA increased the sensitivity of HL60 and K562 cell lines to daunorubicin in a sequence-specific manner.     

Effects of phosphodiesterase inhibitor-induced insulin resistance on glucose and lipid metabolism in rats

AIM:To investigate the effects of milrinone (a selective phosphdiesterase III inhibitor PDE₃) on insulin secretion, blood glucose, plasma free fatty acids (FFA) and dose-response relationship, and assess possible effects of milrinone on glucose metabolism and insulin sensitivity in conscious rats.METHODS:The catheterized nonstressed rats were administered by the varying doses of milrinone (1, 5, 25 μmol/kg) and were compared with controls. A hyperinsulinaemic- euglycaemic clamp was established in awake rats, and milrinone(25 μmol/kg) and 25% dimethyl sulfoxide (DMSO, as a control) were given at 120 min during hyperinsulinaemic- euglycaemic clamp. Glucose turnover was decided by gas chromatograph mass spectrometer (GC-MS).RESULTS:After dosing, plasma FFA levels in 3 milrinone groups significantly increased compared with the controls and before dosing. The percentages of elevation of FFA by the different milrinone doses were very similar, 50%, 52%, 55% for 1, 5, 25 μmol/kg respectively at 2 min after dosing. Plasma insulin levels were significantly elevated in the 5 and 25 μmol/kg groups, and the effect of milrinone on glucose concentration was detectable only 25 μmol/kg group. During hyperinsulinaemic clamp, there were significant increase in plasma FFA (from 173.1±15.2 to 633.8±87.3 μEq/L) and hepatic glucose production (HGP), and a significant decrease in glucose infusion rates (GIR) (to about 21%).CONCLUSION:These data suggest that milrinone impaires the abilities of insulin to suppress lipolysis and HGP, and insulin-mediated glucose utilization in peripheral tissue. Therefore, milrinone administration may induce an acute insulin resistancein vivo.     

麦蚜对吡虫啉的敏感性及吡虫啉有效用量的评价

室内测定结果表明 ,禾谷缢管蚜对吡虫啉的敏感性比麦长管蚜高 ,其LC₅₀之比为1∶3左右。田间试验结果明确 ,吡虫啉持效性好 ,其持效期与吡虫啉用量和麦蚜种类有关。小麦穗蚜发生始盛期是吡虫啉防治麦蚜的最佳时期 ,防治禾谷缢管蚜最佳有效用药量为1g/667m²,麦长管蚜为2g/667m²。     

棉铃虫性诱剂诱捕器的改进及其应用研究

利用废弃的食用油油壶制成棉铃虫诱捕器,可提高诱蛾的效果。挡板距诱捕器器口的距离以3cm的效果最佳。与常规水钵、水盆诱捕器相比较,全年诱蛾总量分别增加116.3％和减少79.8％,但诱蛾灵敏度均高出18.72％。     

Effect of insulin on the secretion of VEGF and its receptor in serum-free cultured bovine thoracic aortic endothelial cells

AIM: This study was designed to investigate the secretion of VEGF and its receptor (flt-1 or flk-1/KDR) protein by cultured bovine thoracic aortic endothelial cells treated with various insulin concentrations. METHODS: Endothelial cells was isolated from bovine thoracic aorta, and cultured in serum-free medium, then incubated with different insulin concentrations (30 mU/L, 300 mU/L, 3 000 mU/L). The level of VEGF and its receptor (flt-1 or flk-1/KDR) protein were detected by immunohistochemical staining. RESULTS: As compared with no insulin group, the expression of VEGF protein in low insulin concentration (30 mU/L and 300 mU/L) groups were significantly increased (P＜0.01). The expression of VEGF protein in high insulin concentration (3 000 mU/L) group was significantly decreased (P＜0.05). Howerer, no difference of the expression of VEGF receptor (flt-1 or flk-1/KDR) protein among all groups (P＞0.05) was observed. CONCLUSION: Low concentration insulin up-regulates the VEGF protein expression while high concentration insulin down-regulates the VEGF protein expression in bovine thoracic aortic endothelial cells, but insulin had no directly effect on the VEGF receptor (flt-1 or flk-1/KDR) protein expression in bovine thoracic aortic endothelial cells.