260 research outputs found

    Rate Control Strategy Based on the Distributed Character of DCT Coefficients

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    根据缓存器的状态和信道速率为待编码帧在图像层上预分配目的视频编码比特数 ,使用DCT系数分布特性来表征图像特性 ,继而为帧内每一具体宏块选定最佳量化因子 ,提出了基于DCT系数分布特性的码率控制策略 .并分析了算法的复杂度 ,提出了改进策略 .模拟实验表明 ,该码率控制策略能有效地减少、避免缓存器出现上、下溢的情况 ,而输出码率趋于稳定 .提高了重建图像的信噪比 ,并且在视频图像质量没有明显失真的前提下 ,改进了计算复杂度 .Rate control strategy based on the distributed character of DCT coefficients is proposed , we allocates the target number of bits firstly on picture layer based on the status of the buffer and the channel rate, and then denotes the characteristics of the picture by the distributed characteristics of the DCT coefficients and select a best quantized parameter for every macroblock in a frame. The complexity of the algorithm is analyzed and an improved method is proposed. The experiment shows that this rate control strategy can effectively reduce and avoid the overflow and underflow of the encoder buffer, and the output bit rates tend to stabilization. The PSNR of the reconstructed picture is raised, and the complexity of the algorithm is improved with no visible distortion in video image.安徽省教委自然科学基金资助项目 (99j10 0 18

    Advances for the Ruthenium Complexes-Based Homogeneous Catalytic Hydrogenation of Oxalates to Ethylene Glycol

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    草酸酯加氢是重要的有机化学反应,在工业制乙二醇生产中有着重要的应用.对钌金属配合物均相催化反应的研究进行了综述.以催化反应体系为焦点,探讨了多种; 因素如温度、氢气压力、催化剂浓度、反应时间、添加剂等对底物转化率以及产物选择性的影响,并讨论了催化反应机理,其中金属-配体协同促进的H_2分子异; 裂,进而完成对底物分子中酯基依次加氢的反应机理是探讨的重点,这为新型催化剂的设计和应用提供参考.Hydrogenation of oxalates is one of the important organic reactions, which has an ultimate use for the industrial production of ethylene glycol. The studies on the ruthenium complexes-based homogeneous catalytic reaction systems are herein summarized. With the focus on the catalytic reaction systems, the important factors with significant influences on the oxalate transformation efficiency as well as the product selectivity are discussed, including temperature, H-2 pressure, catalyst concentration, reaction duration, additives, and so on. The catalytic reaction mechanisms are also discussed in detail, where the mechanism for the H-2-heterolysis promoted under the metal-ligand cooperation for the oxalate hydrogenation to ethylene glycol is enhanced. This study would be useful for designing the new catalyst applicable in industry.National Natural Science Foundation of China [21473142, 91545115,; 21473145]; Innovative Research Team of China [IRT_14R31, J1310024

    Effects of the Xitongxiao prescription on apoptosis and proliferation of chondrocytes in knee

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    目的:探讨膝痛消方对促进软骨细胞增殖和抑制IL-1β诱导的软骨细胞凋亡的作用。方法:体外培养膝关节软骨细胞,用阿利新蓝染色方法检测软骨细胞蛋白多糖,用Ⅱ型胶原免疫荧光染色检测软骨细胞Ⅱ型胶原的表达,以鉴定软骨细胞;用MTS检测软骨细胞的增殖;用IL-1β诱导软骨细胞凋亡,AnnexinV/PI双染检测细胞凋亡。结果:膝关节剥离得到的细胞形态为多角形或梭形,阿利新蓝与Ⅱ型胶原免疫荧光染色均呈阳性,证明分离培养的细胞为软骨细胞。MTS实验结果发现膝痛消方提取物处理软骨细胞后检测到的OD值随浓度增加而增加且显著高于对照组。此外,IL-1β处理诱导软骨细胞凋亡,而膝痛消方提取物能够有效地抑制IL-1β引起的细胞凋亡。结论:膝痛消方能促进软骨细胞的增殖,抑制IL-1β诱导的软骨细胞的凋亡。以上发现为膝痛消方临床上治疗膝关节骨性关节炎提供药理作用依据。Objective:To investigate the effects of the Xitongxiao prescription on the cell proliferation and the inhibition of IL-1β-induced apoptosis of chondrocytes.Methods:To identify chondrocytes,the articular chondrocytes were cultured in vitro;staining with alcian blue was used to detect the protein polysaccharide,and staining with collagen immunofluorescence was used to examine the expression of type II collagen in chondrocytes.The proliferation of chondrocytes was determined by MTS.Apoptosis of chondrocytes was induced by IL-1β,and the effect of apoptosis was tested by Annexin V/PI double staining.Results:The morphology of the cells obtained from the knee joint was polygonal or fusiform.The tested results of Alcian blue and collagen immunofluorescence staining were positive.These together certified that the isolated cells were knee chondrocytes.MTS assay results showed that the detected OD values were dosedependently increased and they were significantly higher than those of the control group.In addition,the apoptosis of chondrocytes was induced by IL-1βtreatment.While the extract of the Xitongxiao prescription could effectively inhibit the IL-1β-induced apoptosis of chondrocytes.Conclusion:The Xitongxiao prescription could promote the proliferation of chondrocytes and inhibit the apoptosis of chondrocytes induced by IL-1β.The above findings may provide one of pharmacological mechanisms of the Xitongxiao for clinical treatment of knee osteoarthritis.厦门市科技计划项目(3502z20144031);福建省自然科学基金计划资助项目(2015J01065)

    束缚和异氟烷麻醉对大鼠心率变异性及HPA轴影响的比较

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    目的为了观察束缚固定和异氟烷(流量:0.8 L,浓度:1.5%)麻醉状态中大鼠的心率变异性的变化;并通过比较9天每天30 min束缚干预和异氟烷麻醉对大鼠的体重、痛阈以及与HPA轴相关激素的影响,来评估长期使用异氟烷麻醉和束缚固定对大鼠应激程度的影响,选择更适宜的大鼠固定方法,为基础医学的实验方法提供重要的参考。方法 SD大鼠随机分为3组:空白组,束缚组,异氟烷麻醉组。急性实验通过记录大鼠心电图15 min,观察束缚固定和异氟烷麻醉情况下大鼠心率,心率变异性的变化。慢性实验中比较连续干预9天(30 min/d)前后3组大鼠体重、痛阈变化以及与应激状态相关激素含量的变化。结果 1)急性试验:与空白组大鼠相比,束缚干预和异氟烷麻醉均造成大鼠心率显著增加,具有统计学意义(P 0.05)。结论以上结果提示:低浓度的异氟烷造成麻醉中大鼠心率增加,心率变异性下降,产生以交感兴奋为主的自主神经功能状态改变。多次束缚固定易造成大鼠HPA轴激活,产生慢性应激的效应。在长期需要固定动物的实验中,与束缚固定相比异氟烷麻醉是更好的固定方法。国家自然科学基金(81674083

    Environmental Behavior and Risk Assessment of Organic Phosphorus Pesticides at Water from Jiulong River Estuary

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    利用SPE GC FPD测定了九龙江口水体中 1 7种有机磷农药的浓度 ,总有机磷农药 (1 7种 )的含量范围是1 3 4 8~ 3 5 4 6ng/L ,平均 2 2 7 2ng/L .对其各组分的含量与行为特征进行分析表明 ,5种有机磷农药 (甲胺磷、敌敌畏、马拉硫磷、氧乐果、乐果 )在各站位均占主要部分 ,其行为受复杂的来源输入及河口的水动力影响 .对九龙江口水体中的有机磷农药的含量与其他地区进行比较 ,评价了该河口水体中有机磷农药的污染水平及风险概率Organic phosphorus pesticides (OPPs) were determined by SPE-GC-FPD. The contents of the total seventeen OPPs ranged from 134.8ng/L to 354.6ng/L (the mean was 227.2ng/L) at water in Jiulong River Estuary (JLRE). The distribution and behavior characteristics of OPPs indicated that five main OPPs (Methamidophos, Dichlorvos, Malathion, Omethoate, Dimethoate) were predominant of the total OPPs, which were affected by the complicated hydrological kinetics. When compared with other areas, the OPPs concentration level in JLRE was some moderate. But the risk evaluation of OPPs in JLRE indicated that some kinds of OPPs (Methamidophos, Dichlorvos, Omethoate) had threat to the ecological environment and human health.海洋环境科学教育部重点实验室开放基金项目(MEL0 10 4);; 中国博士后科学基金项目 ( 2 0 0 2 466

    The effect of nurse initiated patient/family education strategy on people with schizophrenia in Beijing

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    2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    旋转玻碳电极上二茂铁的电化学阻抗行为及其与DNA的相互作用

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    应用旋转圆盘电极和电化学阻抗法研究了二茂铁在Tris-NaC l(pH=7.2)缓冲溶液中于旋转玻碳电极上的电化学阻抗行为及其与DNA的相互作用.结果表明,二茂铁于旋转电极的伏安曲线呈现明显的极限电流平阶,而其交流阻抗谱则出现两个电容弧.二茂铁与DNA的作用,若受扩散过程控制则其极限扩散电流随DNA浓度增大而减小,而在电化学控制过程中则表现为电化学反应电阻随DNA浓度增大而增大.根据旋转圆盘电极和电化学阻抗谱测试,表明由这两种方法数据拟合求得的二茂铁条件电位速率常数能够很好地相互吻合,但如存在DNA时,则其条件电位速率常数有一定程度的减小

    闽江口水、间隙水和沉积物中有机氯农药的含量

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    [摘要]:利用GC2ECD 和GC2MSD 对1999 年11 月闽江口水、间隙水和沉积物中的有机氯农药进行了研究. 结果显 示,闽江口水中有机氯农药的含量范围是01532~1182μg/ L ,间隙水中有机氯农药的含量为4154~1317μg/ L ,沉 积物(干重,以下讨论到的沉积物,无特别说明都是干重表示) :28179~52107μg/ kg ;与其他河口如珠江口、九龙江 口相比,闽江口的污染水平居中. 间隙水的污染物浓度普遍高于其上覆水的浓度,而沉积物中的浓度大于间隙水、 表层水,是由于有机污染物在水体中倾向于吸附在沉积物颗粒,并且通过再悬浮从底层向上迁移. 对水体中有机 氯农药各组分的含量及特征进行了分析,发现有机氯农药的主成分为:β2HCH ,DDE ,Heptachlor (七氯) ,Endosulfan Ⅱ(硫丹) ,Methoxychlor (甲氧滴涕) . DDE、β2HCH、Endosulfan Ⅱ分别占DDTs、HCHs 和硫丹的主要部分;有机氯 农药各组分间有正相关性,表明其河口有机氯农药陆源的土壤输入与相似的环境行为;对该河口的污染水平进行 了初步的评价,HCHs 符合国家海水水质一级标准,DDTs 则超过该标准.[Abstract]:The concentrations of 18 organochlorine pesticedes in water , pore water and surface sediment from Minjiang River Estuary were analyzed by GC2ECD , and confirmed by GC2MSD. The range of organochlorine pesticides was 01532~1182μg/ L at water , 4154~1317μg/ L at pore water , and 28179~52107μg/ kg at sediment . Compared with the results of other estuaries and gulfs (Pearl River Estuary , Jiulong River Estuary and so on) , it showed that the pollu2 tion of organochlorines in Minjiang was some moderate. The concentration difference in surface water , middle water , bottom water , pore water and sediment , due to the higher affinity of these hydrophobic compound for sedimentary phase than to water and a potential flux of pollutants from sediment to overlying water. The predominance ofβ2HCH ,DDE , Heptachlor , Endosulfan Ⅱand Methoxychlor in all water , pore water and sediment were clearly observed. On average , DDE、β2HCH、Endosulfan Ⅱoccupied the most part of total DDTs , HCHs and Endosulfans respectively , indicated the fate of these parent compounds or congeners. At the same time , it was found that thepositive relationship among the in2 dividual organochlorine components (HCHs , DDTs and Endosulfans) , which indicated that the similar of the source and behavior for organochlorine pesticides.海洋环境科学教育部重点实验室开放基金与教育 部重点基金联合资

    疫苗市场概况和发展趋势

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    疫苗是公共卫生领域最大的成就之一,疫苗的接种是预防和控制传染病最经济有效的手段。目前,全球共批准预防性疫苗77种,用于预防41种疾病。全球疫苗市场总额近年来稳步增长,2017年达到277亿美元。国际疫苗四大巨头葛兰素史克、默沙东、辉瑞和赛诺菲巴斯德在不断的并购整合下,占据全球90%的销售额。我国疫苗市场发展迅速,2017年市场总额达224亿元,且疫苗品种不断丰富。但我国疫苗产业水平与发达国家仍存在明显差距。需加大疫苗研究投入、合理布局、完善监管制度以推动技术创新,实现我国从疫苗大国迈向疫苗强国

    Iodine nutrition status of pregnant women in Xiamen City after adjusting iodized salt concentration

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    目的掌握gb 26878-2011《食用盐碘含量》标准执行后,厦门市妊娠期妇女碘营养状况,为卫生策略的制定提供依据。方法选择厦门市翔安区新店镇为调查点,调查妊娠期妇女食用新标准碘盐前后家中的碘盐覆盖率、合格碘盐食用率、尿碘、尿比重水平。结果基线调查及新标准实施后第1到第5次评估,妊娠期妇女家庭碘盐覆盖率均达到100%,盐碘中位数分别为27.8、25.7、24.3、23.7、24.3和25.8 Mg/kg,5次评估的碘盐含量均比基线调查明显减少(均P0.05);基线调查及5次评估测得尿比重均数分别为1.0123、1.0153、1.0180、1.0143、1.0141和1.0132。第1、2、3次评估的尿比重水平均高于基线调查尿比重水平(均P0.05)。结论新标准实施后,妊娠期妇女家中食盐含碘量显著减少,新标准实施前后妊娠期妇女均处于碘营养不足状态,需加强该人群碘营养,保障下一代健康。[Objective]To understand the iodine nutrition status of pregnant women after implementation of‘Edible Salt Iodine Content'( GB26878-2011),and provide evidence for developing health policy.[Methods]The coverage rate of iodized salt,proportion of households using adequately iodized salt,urine-iodine and specific gravity of urine in pregnant women were investigated in Xindian Town of Xiang'an District in Xiamen City which was chosen as the research spot.[Results]In the baseline investigation and during the first-fifth self-assessment stage after carrying out the new standards,the coverage rates of iodized salt were all 100% and the iodine median value in pregnant women was 27.8 mg / kg,25.7 mg / kg,24.3 mg / kg,23.7 mg / kg,24.3 mg / kg and25.8 mg / kg,respectively.The iodine contents in the first-fifth selfassessment stage were all less than that in the baseline survey( all P 0.05).The proportion of urine in pregnant women in the baseline investigation and the first- fifth self-assessment stage was 1.012 3,1.015 3,1.018 0,1.014 3,1.014 1 and 1.013 2 respectively.The proportions of urine in the first-third self-assessment stage were all higher than the baseline survey( all P 0.05).[Conclusion]After the implementation of the new standard,the iodinated content in salt in pregnant households has been reduced significantly.But the pregnant women are in iodine malnutrition before and after implementation of the new standard.It is necessary to strengthen the iodine nutrition for the health of the fetus.福建省科技厅自然基金面上项目(项目编号:2012D046); 厦门市科技局科技计划项目(项目编号:3502Z20124057
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