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361.
自制微波无极紫外灯(MWUVL)发出的185 nm UV占总辐射量的12%,是普通低压汞灯的1.7倍左右.利用自制MWUVL研究了罗丹明B(RhB)水溶液的光降解.研究表明,酸性条件有利于RhB的光降解;ρ初始≥60mg.L-1的RhB溶液在光降解过程中有沉淀析出;pH=4.0的100 mg.L-1RhB溶液光照75 m in后,析出的沉淀质量接近初始RhB质量的一半,脱色率达99.4%,CODC r下降77.4%;RhB的降解主要是185 nm直接光解和OH自由基氧化的共同作用的结果.  相似文献   
362.
目的:回顾分析11例川崎病(KD)的临床资料,观察其临床特征。方法:参照第三届国际KD会议修订的诊断标准,分析11例KD患儿各种临床表现出现的时间及发生率。结果:发热、皮疹、淋巴结肿大、指(趾)末端脱皮、双球结膜充血、唇红皲裂的发生率分别为100%、64%、91%、91%、55%、91%。指(趾)末端脱皮出现在病程第10~15 d,肛周皮肤潮红在病程第13d出现,阴囊皮肤潮红在起病第7 d出现,病程4~9 d内发生心脏冠状动脉病变达45%。本病主要用阿司匹林和大剂量静脉注射丙种球蛋白治疗。结论:发热、淋巴结肿大、皮疹(包括出现卡癜红)、唇和口腔粘膜改变是川崎病的早期主要临床表现。肛周潮红及其脱皮、阴囊脱皮、血小板(PLT)增高、C反应蛋白(CRP)和血沉(ESR)升高有早期诊断的价值。疑似病例应尽早行二维超声(2DE)检查,心脏冠状动脉的病变可为该病确诊提供有力的佐证。  相似文献   
363.
In the era of big data, correlation analysis is significant because it can quickly detect the correlation between factors. And then, it has been received much attention. Due to the good properties of generality and equitability of the maximal information coefficient(MIC), MIC is a hotspot in the research of correlation analysis. However, if the original approximate algorithm of MIC is directly applied into mining correlations in big data, the computation time is very long. Then the theoretical time complexity of the original approximate algorithm is analyzed in depth and the time complexity is n2.4 when parameters are default. And the experiments show that the large number of candidate partitions of random relationships results in long computation time. The analysis is a good preparation for the next step work of designing new fast algorithms.  相似文献   
364.
基于Unity3D研制了一种由地面控制终端、机器人本体和三维仿真系统3部分组成的水下机器人半实物仿真系统,为水下机器人开发过程中的性能测试、控制算法分析和人员操作培训提供了仿真和测试平台。该系统采用同一地面控制终端作为三维仿真系统和机器人控制系统的统一指令输入源,以实现虚拟对象和机器人本体的同步工作,可对系统进行实时监测、调参。采用多目视觉技术对机器人位置采集,对传感器数据进行卡尔曼滤波处理。机器人运动仿真试验结果表明,机器人实际运动路径和仿真规划路径基本相同,该系统动态响应性和控制系统同步性较好。  相似文献   
365.
通过调查我国水肥利用的现状,指出我国农业水利中干旱缺水、非点源污染、水资源利用率低下和灌排系统不配套等问题,提出灌区水肥高效利用需深入研究的热点问题,对探讨水肥高效利用和灌排系统管理理论,指导我国灌排系统精量调控,以最少的水肥投入量获取最佳的灌区产量和经济及生态环境效益,具有重要意义.  相似文献   
366.
367.
Lin Z  Bei JX  Shen M  Li Q  Liao Z  Zhang Y  Lv Q  Wei Q  Low HQ  Guo YM  Cao S  Yang M  Hu Z  Xu M  Wang X  Wei Y  Li L  Li C  Li T  Huang J  Pan Y  Jin O  Wu Y  Wu J  Guo Z  He P  Hu S  Wu H  Song H  Zhan F  Liu S  Gao G  Liu Z  Li Y  Xiao C  Li J  Ye Z  He W  Liu D  Shen L  Huang A  Wu H  Tao Y  Pan X  Yu B  Tai ES  Zeng YX  Ren EC  Shen Y  Liu J  Gu J 《Nature genetics》2012,44(1):73-77
To identify susceptibility loci for ankylosing spondylitis, we performed a two-stage genome-wide association study in Han Chinese. In the discovery stage, we analyzed 1,356,350 autosomal SNPs in 1,837 individuals with ankylosing spondylitis and 4,231 controls; in the validation stage, we analyzed 30 suggestive SNPs in an additional 2,100 affected individuals and 3,496 controls. We identified two new susceptibility loci between EDIL3 and HAPLN1 at 5q14.3 (rs4552569; P = 8.77 × 10(-10)) and within ANO6 at 12q12 (rs17095830; P = 1.63 × 10(-8)). We also confirmed previously reported associations in Europeans within the major histocompatibility complex (MHC) region (top SNP, rs13202464; P < 5 × 10(-324)) and at 2p15 (rs10865331; P = 1.98 × 10(-8)). We show that rs13202464 within the MHC region mainly represents the risk effect of HLA-B*27 variants (including HLA-B*2704, HLA-B*2705 and HLA-B*2715) in Chinese. The two newly discovered loci implicate genes related to bone formation and cartilage development, suggesting their potential involvement in the etiology of ankylosing spondylitis.  相似文献   
368.
Aging is associated with reductions in hippocampal volume that are accelerated by Alzheimer's disease and vascular risk factors. Our genome-wide association study (GWAS) of dementia-free persons (n = 9,232) identified 46 SNPs at four loci with P values of <4.0 × 10(-7). In two additional samples (n = 2,318), associations were replicated at 12q14 within MSRB3-WIF1 (discovery and replication; rs17178006; P = 5.3 × 10(-11)) and at 12q24 near HRK-FBXW8 (rs7294919; P = 2.9 × 10(-11)). Remaining associations included one SNP at 2q24 within DPP4 (rs6741949; P = 2.9 × 10(-7)) and nine SNPs at 9p33 within ASTN2 (rs7852872; P = 1.0 × 10(-7)); along with the chromosome 12 associations, these loci were also associated with hippocampal volume (P < 0.05) in a third younger, more heterogeneous sample (n = 7,794). The SNP in ASTN2 also showed suggestive association with decline in cognition in a largely independent sample (n = 1,563). These associations implicate genes related to apoptosis (HRK), development (WIF1), oxidative stress (MSR3B), ubiquitination (FBXW8) and neuronal migration (ASTN2), as well as enzymes targeted by new diabetes medications (DPP4), indicating new genetic influences on hippocampal size and possibly the risk of cognitive decline and dementia.  相似文献   
369.
Leber congenital amaurosis (LCA) is a blinding retinal disease that presents within the first year after birth. Using exome sequencing, we identified mutations in the nicotinamide adenine dinucleotide (NAD) synthase gene NMNAT1 encoding nicotinamide mononucleotide adenylyltransferase 1 in eight families with LCA, including the family in which LCA was originally linked to the LCA9 locus. Notably, all individuals with NMNAT1 mutations also have macular colobomas, which are severe degenerative entities of the central retina (fovea) devoid of tissue and photoreceptors. Functional assays of the proteins encoded by the mutant alleles identified in our study showed that the mutations reduce the enzymatic activity of NMNAT1 in NAD biosynthesis and affect protein folding. Of note, recent characterization of the slow Wallerian degeneration (Wld(s)) mouse model, in which prolonged axonal survival after injury is observed, identified NMNAT1 as a neuroprotective protein when ectopically expressed. Our findings identify a new disease mechanism underlying LCA and provide the first link between endogenous NMNAT1 dysfunction and a human nervous system disorder.  相似文献   
370.
A population of the dwarf bear-poppy ( Arctomecon humilis Coville, Papaveraceae) at Red Bluff, Washington County, Utah, was monitored twice annually between 1987 and 2002. This is a narrowly endemic, gypsophilous species that has been formally listed as endangered since 1979. During the 16 years of observation, density of this species has fluctuated between 3 and 1336 individuals on the 0.07-ha monitoring plot. Moderate to large recruitments of seedlings occurred in 1992, 1995, and 2001. Seedling recruitments from a large, long-lived seed bank are triggered by abundant precipitation during the February-April period. At least 5.0 cm of rainfall is required during that interval to produce any seedlings. Seedlings experienced considerable mortality in the 1st few months of life in all observed cases. The average seedling initiated in the very large recruitment event of 1992 survived for only 2.6 years. Seedlings in that cohort that were alive 1 year after germination had an average longevity of 4.6 years. None of the seedlings that emerged in 1992 were still alive in October 2002. Mortality in this species was poorly correlated with fluctuations in precipitation or temperature. No epidemics of parasites or herbivores were observed. Mortality in the species appears to be caused by a variety of factors acting over a cohort's lifetime.  相似文献   
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