农业高新技术推动农业跨越发展的若干问题探讨

探讨了运用农业高新技术推动农业跨越发展面临的一系列问题，并提出若干对策和运动模式。     

数学史与高等数学教学

数学史应用于高等数学教学是当前的一种趋势，它相对于传统的课堂教学更能激发学生的兴趣，使学生体会到数学的价值，是课堂教学的指南。     

农机制造业实施AMT的现状、问题及对策

针对我国农机制造业实施AMT的现状以及存在的若干问题,提出我国农机业实施先进制造技术必须注重人才培养、逐步提高自动化水平、推进实施虚拟组织模式和加强生产和管理的一体化集成。     

Canine insulinomas appear hyperintense on MRI T2‐weighted images and isointense on T1‐weighted images

Clinical and imaging diagnosis of canine insulinomas has proven difficult due to nonspecific clinical signs and the small size of these tumors. The aim of this retrospective case series study was to describe MRI findings in a group of dogs with pancreatic insulinomas. Included dogs were presented for suspected pancreatic insulinoma, MRI was used to assist with localization of the primary lesion, and the diagnosis was confirmed with surgical exploratory laparotomy and histopathology. The MRI studies for each dog were retrieved and the following data were recorded: T1‐weighted and T2‐weighted signal intensities, type of contrast enhancement, size and location of the primary lesion, and characteristics of metastatic lesions (if present). A total of four dogs were sampled. In all patients, the insulinoma displayed high‐intensity signal on T2‐weighted fat saturation images, similar to human studies. On postcontrast T1‐weighted fat saturation images, the tumors were primarily isointense to normal pancreatic tissue, in contrast to human studies where a low‐intensity signal is typically identified. Abnormal islet tissue was detected with MRI in all four dogs and metastases were identified in three dogs. Variations in the MRI appearance of primary and metastatic lesions were identified and could have been related to the variation of tissue composition, including the presence of neoplastic cells, hemorrhage, and fibrovascular stroma, and to the transformation of this tissue throughout the disease process.     

Advanced glycation end products induce apoptosis of human ovarian granulosa COV434 cells and up-regulate pro-inflammatory cytokine HMGB1 autocrine

AIM:To study whether advanced glycation end products (AGEs) induce the apoptosis of human ovarian granulosa COV434 cells, and to explore the possible mechanism. METHODS:Human ovarian granulosa COV434 cells were treated with AGEs at different concentrations. Flow cytometry was used to observe the apoptotic rate. The protein levels of caspase-3 and cleaved caspase-3 were determined by Western blot. The release of high mobility group box 1 protein (HMGB1) in the culture supernatant was measured by ELISA. RESULTS:Compared with control group, early apoptotic rate and late apoptotic rate in 100 mg/L AGEs group and 200 mg/L AGEs group were significantly increased (P<0.05). No obvious difference of caspase-3 protein level in each group was observed, while the protein levels of cleaved caspase-3 in 100 mg/L AGEs group and 200 mg/L AGEs group were significantly increased compared with control group (P<0.05). In addition, compared with control group, pro-inflammatory factor HMGB1 in the culture medium in 100 mg/L AGEs group and 200 mg/L AGEs group was significantly increased. CONCLUSION:The apoptosis of human ovarian granulosa COV434 cells induced by AGEs may be related to pro-inflammatory reaction.     

谁是先进生产力的代表

只有工人阶级才是先进生产力的始终代表。其他阶级只能在特定时期、特定领域、特定方面、特定环节上成为先进生产力的代表。     

农田立体种植优化模式研究——II、优化模式的增值效益

本文在1986—88年水、旱种植优化模式随机区组试验和对比示范所获产量的基础上,以当地三年平均价格计算产值,研究各优化模式的增值效能,结果表明,各优化模式的亩产值数倍,甚至数十倍于传统模式,采用这些优化模式已成为当地农民脱贫致富、走向小康的重要途径。     

Inhibitory effect of catalpol on inflammation and expression of RAGE in EA.hy926 cells induced by advanced glycation end products

AIM: To investigate the inhibitory effect of catalpol on inflammation in EA.hy926 cells induced by advanced glycation end products(AGEs) and to explore its antioxidant mechanisms.METHODS: Human endothelial cell line EA.hy926 was cultured and randomly divided into control group, catalpol(0.5 mmol/L) group, AGEs group, high-dose(0.5 mmol/L) catalpol+AGEs group, middle-dose(0.25 mmol/L) catalpol+AGEs group and low-dose(0.05 mmol/L) catalpol+AGEs group. Intracellular reative oxygen species(ROS) production was detected by laser scanning confocal microscopy. The levels of monocyte chemotactic protein-1(MCP-1), tumor necrosis factor-α(TNF-α) and vascular cell adhesion molecule-1(VCAM-1) in culture supernatant were detected by commercial ELISA kits. The expression of MCP-1, TNF-α, VCAM-1 and receptor for advanced glycation end products(RAGE) in the EA.hy926 cells were detected by Western blot.RESULTS: In high-dose catalpol+AGEs and middle-dose catalpol+AGEs groups, the generation of ROS was decreased significantly. The levels of MCP-1, TNF-α and VCAM-1, and protein expression of MCP-1, TNF-α and VCAM-1 were significantly lower. The expression of RAGE protein in EA.hy926 cells were significantly inhibited(P<0.05).CONCLUSION: Catalpol effectively inhibits the AGEs-induced oxidative stress and inflammation in EA.hy926 cells, which may be associated with a decrease in the expression of RAGE.     

OPTIMIZATION DESIGN OF ADVANCED CORRECTION OF THE CONTROL SYSTEM BY A PASSIVE NETWORK

Optimization design of correction of the control systemby a passive network is studied in this paper.The design method guan-rantees collocation of a closed loop pole in a desired position,but alsominimizes the gain of the system amplifier,thus making the technicalrealization of the system easier.The design method is proved in thepaper.