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991.
工业机器人目前在工业生产中有着广泛的应用,在操作人员的引导下可以完成许多示教内容,但机器人缺乏对外界信息变化的足够感知能力,不能对已改变的工作环境做出相应的调整,进而影响加工的精度和质量,因此,给机器人添加一套视觉系统,使机器人能够对外部环境的变化做出相应的调整,提高机器人的灵活性和适应性,对机器人的广泛应用有着重要的意义。本试验通过介绍计算机视觉系统的工作原理和系统组成,研究开发了三自由度机器人,增加了一套视觉系统,实现了对物体的识别、跟踪以及一些其他的操作如:夹持、搬运等,并结合机器人控制卡,使得工业机器人能够很快地识别和跟踪目标物体,从而提高了工业机器人的适应性和灵活性。 相似文献
992.
993.
采用毒土法和喷雾法研究了不同剂型和用量NC-620和稻杰对水稻田稗草、千金子和三棱草的田间防除效果。结果表明,对稗草的株防效从高到低分别是2.5%稻杰、NC-620(4%TB)、有效成分为(下同)100 g/hm2NC-620(33%WG)和80 g/hm2NC-620(33%WG)。NC-620对千金子有一定的防效,防效从高到低是NC-620(4%TB)、100 g/hm2NC-620(33%WG)和80 g/hm2NC-620(33%WG),2.5%稻杰对千金子无防效。三棱草与稗草的株防效基本相同,2.5%稻杰在防除效果上较NC-620好,45 d后防效高达90%以上。稗草、千金子和三棱草鲜重防效与株防效的结果基本相同。 相似文献
994.
城市废水暴露对食蚊鱼肝脏EROD酶活性的影响 总被引:1,自引:1,他引:0
采用动力学酶标荧光法,检测了东莞市数所污水处理厂、制药厂和电子厂废水对食蚊鱼(Gambusia affinis)肝组织中7-ethoxyresorufin o-deethylase(EROD)酶活性的影响,评价了运用EROD酶活性监测水环境污染物的生物效应的可行性。结果显示,食蚊鱼分别暴露于经稀释为20%,40%,60%,80%不同梯度的废水液72 h后,肝脏EROD酶的活性分别与受试城市污水处理厂、制药厂和电子厂的废水之间存在剂量效应关系,EROD酶活性随污水浓度的增加而提高。电子厂废水的最大诱导倍数与对照组的比值可达到5.26,这表明其水体中存在的有机污染物较多,污水处理厂次之,制药厂的出水中污染物最少。研究表明,食蚊鱼肝组织EROD酶活性可以作为监测城市废水污染的理想生物标记物,后续的研究工作应使之标准化。 相似文献
995.
生鲜乳金黄色葡萄球菌污染来源调查及其耐药性 总被引:1,自引:0,他引:1
为考察贵阳市生鲜乳中金黄色葡萄球菌污染环节及其对药物的敏感性,采集贵阳市周边5个大型奶牛场及一个牛奶加工厂的乳区棉签拭子75份和各生产环节奶样310份,按国家标准(GB 4789.10—2010)分离鉴定金黄色葡萄球菌,并测定其对9种常用抗菌药物的敏感性。结果表明:生鲜乳中金黄色葡萄球菌污染主要来源于牛乳头内;传统的"弃前三把奶"工艺对降低生鲜乳中金黄色葡萄球菌污染的作用不明显;规范的乳区消毒可以有效地降低乳头外环境金黄色葡萄球菌对生鲜乳安全的影响;所调查奶牛场的金黄色葡萄球菌对磺胺类、β-内酰胺类和四环素类药物的耐药水平较高。 相似文献
996.
997.
AIM:To study the role of Sonic Hedgehog (Shh) in strontium ranelate (Sr)-induced osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs). METHODS:BMSCs was isolated from 4-week-old rats by adherent culture. The cells in the 3rd~5th generations were induced to differentiate into obteoblasts, and then were treated with different concentrations of Sr and cyclopamine (Cy). The activity of alkaline phosphatase (ALP) was mea-sured by colorimetry. Mineralized nodules were observed by alizarin red staining. The cellular Shh and Runx2 expression was detected by Western blotting. RESULTS:Sr at concentration of 3 mmol/L increased the activity of ALP and induced the formation of mineralized nodules. Sr at concentrations ranging from 0.1 to 5 mmol/L increased the expression of Shh and Runx2 in the BMSCs at 7 d. Furthermore, the peak expression of Shh occurred following the exposure of Sr (1 mmol/L) or Runx2 (3 mmol/L). On the other hand, Sr at concentration of 1 mmol/L showed a time-dependent increase in the expression of Shh and Runx2 from 1 d to 7 d. Cy at concentration of 10 μmmol/L not only obviously inhibited Sr-induced expression of Shh and Runx2, but also antagonized the increase in the ALP activity and mineralization induced by Sr in the BMSCs. CONCLUSION:Sr promotes osteogenic differentiation of BMSCs by increasing the expression of Shh and Runx2. 相似文献
998.
AIM: To observe the effect of captopril on the genesis and development of gastric cancer, and to explore its clinical treatment feasibility for gastric cancer.
METHODS: The human gastric cancer cell line AGS was used to establish a tumor model in nude mice, and the model mice were randomly divided into 3 groups: positive control (5-fluorouracil) group, normal control (saline) group and experimental (captopril) group. After intraperitoneal injection or intragastric administration of the drugs, the tumor growth curve was determined, and the tumor tissues were also sampled to detect the expression of Ki-67, STAT3, Bax and Bcl-2 by real-time quantitative PCR and immunohistochemistry. The apoptosis was detected by TUNEL+DAPI staining. RESULTS: The tumor growth curve showed that the tumor model in the nude mice was successfully established. The tumor volumes among groups showed significantly different after 14 d growth. The increase in the tumor volume in normal control group was significantly faster than that in the other two groups, and that in positive control group was the slowest. The expression of Bax in captopril group increased, and the expression of STAT3, Ki-67 and Bcl-2 was reduced as compared with normal control group and positive control group. Compared with normal control group, the apoptotic rate increased significantly, and the protein expression of p-STAT3 and STAT3 decreased obviously in positive control group and captopril group. CONCLUSION: With better feasibility, angiotensin-converting enzyme inhibitor captopril has a significant effect on treating gastric cancer in the AGS nude mouse model by regulating the expression of STAT3, Bax, Bcl-2 and Ki-67 to accelerate the apoptosis of cancer cells, thus inhibiting tumor growth. 相似文献
999.
Expression of stem cell factor in mast cells isolated from patients with chronic periapical diseases
AIM:To investigate the expression of stem cell factor (SCF) in tryptase -positive mast cells (MCs) in different types of human periapical diseases for determining the role of SCF and MCs in the pathogenesis of periapical diseases. METHODS:A total 50 cases of specimens were involved in this study, including healthy control (n=20), periapical cyst (n=15) and periapical granuloma (n=15). The tissue material was fixed in 10% formalin for at least 48 h, stained with hematoxylin and eosin for the observation of histopathology, stained with immunohistochemistry for identifying MCs and MCs degranulation, and stained with double immunofluorescence for identification of tryptase-SCF double positive MCs. RESULTS:Compared with healthy control, significantly higher densities of both total and degranulated MCs in human periapical lesions were observed. The densities of both total and degranulated MCs in the periapical cyst were significantly higher than that in the periapical granuloma. The density of tryptase-SCF double positive MCs in the periapical lesions was significantly higher than that in the healthy controls. The density oftryptase-SCF double positive MCs in the periapical cyst was significantly higher than that in periapical granuloma. No significant difference in the density of MCs between immunohistochemistry staining and double immunofluorescence staining was observed. CONCLUSION: The tryptase-SCF double positive MCs play an active role in the pathogenesis of the periapical inflammatory lesions, particularly in the formation of fibrous tissue in periapical cyst. The potential role of the tryptase-SCF double positive MCs relates with the initiation, development, and persistence of the periapical inflammatory process. 相似文献
1000.
AIM: To explore the regulatory effect of intermedin (IMD) on pulmonary collagen synthesis and accumulation in rats with pulmonary hypertension induced by high pulmonary blood flow.METHODS: Healthy male SD rats (n=20) were randomly divided into control group (n=7), shunt group (n=7) and shunt with IMD group (n=6). The shunting of abdominal aorta and inferior vena cava was produced in rats of shunt group and shunt with IMD group. After 8 weeks, IMD was administered into the rats of shunt with IMD group subcutaneously by mini-osmotic pump for 2 weeks. Mean pulmonary artery pressure (mPAP), relative medial thickness (RMT) of pulmonary arteries, contents of hydroxyproline, collagen type I and III, bone morphogenetic protein-2 (BMP-2), and the mRNA expression of procollagen I and III in lung tissues were measured and compared. RESULTS: Compared with control group, mPAP and RMT of medium and small pulmonary arteries in the rats of shunt group were significantly increased. Meanwhile, the lung hydroxyproline, collagens I and III and BMP-2 contents, and the mRNA expression of lung procollagen I and III were all significantly increased compared with control group. However, IMD significantly decreased mPAP, alleviated the changes of pulmonary vascular micro-structure, decreased the collagen accumulation and pulmonary tissue homogenate BMP-2 contents, and inhibited the mRNA expression of procollagen I and III in the lung tissue of shunting rats.CONCLUSION: IMD plays a protective role in the development of pulmonary hypertension and pulmonary vascular structural remodeling induced by high blood flow by inhibiting pulmonary collagen synthesis and accumulation, possibly in association with the BMP-2 pathway. 相似文献