检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

弹簧式液体喷射注射过程的建模及实验研究

中国生物医学工程学报 2010年第1期29卷 150-154页

作者：陈凯周华杭州电子科技大学机械工程学院杭州310018

液体喷射注射器是一种利用高速药物射流对人体进行药物和疫苗注射的注射系统。影响注射器注射质量的系统参数包括喷孔直径、药物注射剂量、安瓿直径、推射压力和冲撞距离等。针对以弹簧为驱动力的液体喷射注射系统,提出一种计算喷射压... 详细信息

液体喷射注射器是一种利用高速药物射流对人体进行药物和疫苗注射的注射系统。影响注射器注射质量的系统参数包括喷孔直径、药物注射剂量、安瓿直径、推射压力和冲撞距离等。针对以弹簧为驱动力的液体喷射注射系统,提出一种计算喷射压强的模型。根据该模型计算给定系统参数时喷射压强随时间变化的动态关系和最大喷射滞止压强。计算结果与在相同系统参数下实验测得的动态喷射压强相吻合;不同剂量、不同弹簧系数情况下计算的最大喷射滞止压强亦与实验结果相一致。实验结果验证了所建模型的正确性和有效性。

关键词：无针注射喷射模型滞止压强

Light Regulation to Chlorophyll Synthesis and Plastid Development of the Chlorophyll-Less Golden-Leaf Privet

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2010年第9期52卷 809-816页

作者： Ming Yuan Mo-yun Xui Shu Yuan Yang-Er chen Jun-Bo Du Fei Xu Zhong-Wei Zhang Zi-Chan Guo Zhong-Yi Zhao Hong-Hui Lin Key Laboratory for Bio-Resource and Eco-Environment M~nistry of Education School of Life Sciences Sichuan University Chengdu 610064 China College of Biology and Science Sichuan Agricultural University Ya'an 625014 China Plant Physiology Laboratory School of Life Sciences Sichuan University Chengdu 610064 China

Ligustrum vicaryi L. is a hybrid of Ligustrum ovalifolium Hassk. var. aureo-marginatum and Ligustrum vulgale L., and displays a chlorophyll-less phenotype. Therefore it is widely used as a horticultural shrub because of its golden-color leaves. Its putative mechanism, light responses, chlorophyll synthesis and plastid development were studied. L. vicaryi has a higher level of *** acid （ALA）, but lower levels of chlorophylls compared with L. quihoui. The yellowish phenotype of L. vicaryi upper leaves could be attributed to their hampered conversion from chlorophyllide into chlorophyll a. Despite the enhanced ALA level and the decreased thylakoid stacking in plastids, L. vicaryi golden leaves contain normal levels of Lhcb transcripts and photosystem apoproteins. Furthermore, reactive oxygen species （ROS） accumulation is almost the same in L. vicaryi and L. quihoui. The golden leaves often turn green and the contents of chlorophylls increase with decreasing light intensity. Dynamic changes of chlorophyll- synthesis-system under the light transition were also analyzed.

关键词： CHLOROPHYLL synthesis PLASTIDS PRIVETS SHRUBS ACTIVE oxygen SPECIES

Neolithic millet farmers contributed to the permanent settlement of the Tibetan Plateau by adopting barley agriculture

在线全文

学校读者我要写书评

暂无评论

National Science Review 2019年第5期6卷 1005-1013页

作者： Yu-Chun Li Jiao-Yang Tian Feng-Wen Liu Bin-Yu Yang Kang-Shu-yun Gu Zia Ur Rahman Li-Qin Yang Fa-Hu chen Guang-Hui Dong Qing-Peng Kong State Key Laboratory of Genetic Resources and Evolution/Key Laboratory of Healthy Aging Research of yunnan Province Kunming Institute of Zoology Chinese Academy of Sciences CAS Center for Excellence in Animal Evolution and Genetics Chinese Academy of Sciences Key Laboratory of Western China’s Environmental Systems(Ministry of Education) Lanzhou University CAS Center for Excellence in Tibetan Plateau Earth Sciences and Key Laboratory of Alpine Ecology Institute of Tibetan Plateau Research(ITPCAS) Chinese Academy of Sciences

The permanent human settlement of the Tibetan Plateau(TP) has been suggested to have been facilitated by the introduction of barley agriculture ～3.6 kilo-years ago(ka).However, how barley agriculture spread onto the TP remains *** that the lower altitudes in the northeastern TP were occupied by millet cultivators from 5.2 ka, who also adopted barley farming ～4 ka, it is highly possible that it was millet farmers who brought barley agriculture onto the TP ～3.6 *** test this hypothesis, we analyzed mitochondrial DNA(mt DNA) from 8277 Tibetans and 58 514 individuals from surrounding populations,including 682 newly sequenced whole *** lines of evidence, together with radiocarbon dating of cereal remains at different elevations, supports the scenario that two haplogroups(M9a1a1c1b1a and A11a1a), which are common in contemporary Tibetans(20.9%) and were probably even more common(40–50%) in early Tibetans prior to historical immigrations to the TP, represent the genetic legacy of the Neolithic millet *** haplogroups originated in northern China between 10.0–6.0 ka and differentiated in the ancestors of modern Tibetans ～5.2–4.0 ka, matching the dispersal history of millet *** showing that substantial genetic components in contemporary Tibetans can trace their ancestry back to the Neolithic millet farmers, our study reveals that millet farmers adopted and brought barley agriculture to the TP ～3.6–3.3 ka, and made an important contribution to the Tibetan gene pool.

关键词： Tibetans millet farmers barley agriculture archaeology mitochondrial genomes

Vision-based Vehicle Tracking and Classification on the Highway

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science and Information 2007年第2期5卷 141-149页

作者： Guolian yun Qimei chen Bo Li Xindao Wang Department of Electronic Science and Engineering Nanjing University Nanjing 210093 China

This paper presents algorithms for vision-based tracking and classification of vehicles in image sequences of traffic scenes recorded by a stationary camera. In the algorithms, the central moment and extended Kalman filter of tracking processes optimizes the amount of spent computational resources. Moreover, it robust to many difficult situations such as partial or full occlusions of vehicles. Vehicle classification performance is improved by Bayesian network, especially from incomplete data. The methods are test on a single Intel Pentium 4 processor 2.4 GHz and the frame rate is 25 frames/s. Experimental results from highway scenes are provided, which demonstrate the effectiveness and robust of the methods.

关键词： vision-based vehicle tracking Bayesian network vehicle classification

Tunable wavelength filters using polymer long-period waveguide gratings based on metal-cladding directly defined technique

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2017年第2期26卷 268-273页

作者： Ji-Hou Wang Chang-Ming chen Yang Zheng Xi-Bin Wang yun-Ji Yi Xiao-Qiang Sun Fei Wang Da-Ming Zhang State Key Laboratory on Integrated Optoelectronics College of Electronic Science and Engineering Jilin University Changchun 130012 China

In this work, long-period waveguide grating-based tunable wavelength filters using organic–inorganic grafting poly（methyl methacrylate）（PMMA） materials are designed and fabricated by metal-cladding directly defined *** thermal stabilities and optical properties of the organic–inorganic grafting PMMA core materials are analyzed. Structures and performance parameters of the waveguide gratings and self-electrode heaters are designed and simulated. The contrast of the filter is about 15 d B and the resonant wavelength can be tuned by different electric powers applied to the metal-cladding self-electrode heaters. The temperature sensitivity is 3.5 nm/℃ and the switching time is about 1 ms. The technique is very suitable for realizing the optoelectronic integrated wavelength-division-multiplexing systems.

关键词： organic–inorganic grafting materials polymer optical waveguide long-period grating filter metalcladding defined technique

Silent MRA与3D TOF MRA对颈内动脉海绵窦段的成像质量比较

在线全文

学校读者我要写书评

暂无评论

临床放射学杂志 2019年第5期38卷 923-926页

作者：嵇昀徐凯吴琛刘欣徐州医科大学附属医院影像科 221000

目的比较Silent MRA与3D TOF MRA在颈内动脉海绵窦段的成像质量。方法搜集65例怀疑脑血管疾病患者进行Silent MRA和3D TOF MRA检查,对颈内动脉海绵窦段血管结构采用评分法进行评估。采用Wliconxon秩和检验比较Silent MRA与3D TOF MRA在... 详细信息

目的比较Silent MRA与3D TOF MRA在颈内动脉海绵窦段的成像质量。方法搜集65例怀疑脑血管疾病患者进行Silent MRA和3D TOF MRA检查,对颈内动脉海绵窦段血管结构采用评分法进行评估。采用Wliconxon秩和检验比较Silent MRA与3D TOF MRA在颈内动脉海绵窦段血管结构的评分差异。采用一致性Kappa检验评估观察者之间的一致性。结果两名观察者对65例患者的Silent MRA与3D TOF MRA图像评估具有中度一致性(Kappa=0.787)。Silent MRA与3D TOF MRA原始图像优秀率差异具有统计学意义(P=0.002)。Silent MRA与3D TOF MRA原始图像显示颈内动脉海绵窦段血管评分分别是(1.77±0.553)分、(1.49±0.664)分,差异具有统计学意义(Z=-3.530,P=0.000)。Silent MRA与3D TOF-MRA后处理图像优秀率差异具有统计学意义(P=0.000)。Silent MRA与3D TOF-MRA后处理图像评分分别是(1.77±0.493)分、(1.45±0.613)分,差异具有统计学意义(Z=-4.3750,P=0.000)。结论 Silent MRA对颈内动脉海绵窦段血管质量高于3D TOF MRA。

关键词： Silent MRA 3D TOF MRA 颈内动脉海绵窦段图像质量

Feasibility of endoscopic treatment and predictors of lymph node metastasis in early gastric cancer

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2019年第35期25卷 5344-5355页

作者： Yu-Ning Chu Ya-Nan Yu Xue Jing Tao Mao yun-Qing chen Xiao-Bin Zhou Wen Song Xian-Zhi Zhao Zi-Bin Tian Department of Gastroenterology the Affiliated Hospital of Qingdao University Qingdao 266003 Shandong Province China Department of Pathology the Affiliated Hospital of Qingdao University Qingdao 266003 Shandong Province China Department of Epidemiology and Health Statistics School of Public Health Qingdao University Qingdao 266021 Shandong Province China Endoscopy Center the Affiliated Hospital of Qingdao University Qingdao 266003 Shandong Province China

BACKGROUND Endoscopic submucosal dissection (ESD) has been routinely performed in applicable early gastric cancer (EGC) patients as an alternative to conventional surgical operations that involve lymph node dissection. The indications for ESD have been recently expanded to include larger, ulcerated, and undifferentiated mucosal lesions, and differentiated lesions with slight submucosal invasion. The risk of lymph node metastasis (LNM) is the most important consideration when deciding on a treatment strategy for EGC. Despite the advantages over surgical procedures, lymph nodes cannot be removed by ESD. In addition, whether patients who meet the expanded indications for ESD can be managed safely remains controversial. AIM To determine whether the ESD indications are applicable to Chinese patients and to investigate the predictors of LNM in EGC. METHODS We retrospectively analyzed 12552 patients who underwent surgery for gastric cancer between June 2007 and December 2018 at the Affiliated Hospital of Qingdao University. A total of 1262 (10.1%) EGC patients were eligible for inclusion in this study. Data on the patients’ clinical, endoscopic, and histopathological characteristics were collected. The absolute and expanded indications for ESD were validated by regrouping the enrolled patients and determining the positive LNM results in each subgroup. Predictors of LNM in patients were evaluated by univariate and multivariate analyses. RESULTS LNM was observed in 182 (14.4%) patients. No LNM was detected in the patients who met the absolute indications (0/90). LNM occurred in 4/311 (1.3%) patients who met the expanded indications. According to univariate analysis, LNM was significantly associated with positive tumor marker status, medium (20-30 mm) and large (>30 mm) lesion sizes, excavated macroscopic-type tumors, ulcer presence, submucosal invasion (SM1 and SM2), poor differentiation, lymphovascular invasion (LVI), perineural invasion, and diffuse and mixed Lauren’s type

关键词： Early gastric cancer Lymph node metastasis Predictors Endoscopic submucosal dissection Expanded indications

多维分解加噪算法在智能电网隐私保护中的优化

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

重庆大学学报（自然科学版） 2018年第9期41卷 86-93页

作者：陈倩刘云昆明理工大学信息工程与自动化学院昆明650500

在智能电网的数据采集监测中,针对用户隐私泄露安全隐患问题,采取加噪为主的方式来实现隐私保护。提出一种基于多维分解的拉普拉斯噪声算法(MDLN,multidimensional laplacian noise algorithm),该算法将原始测量值分解成多维数据,并根... 详细信息

在智能电网的数据采集监测中,针对用户隐私泄露安全隐患问题,采取加噪为主的方式来实现隐私保护。提出一种基于多维分解的拉普拉斯噪声算法(MDLN,multidimensional laplacian noise algorithm),该算法将原始测量值分解成多维数据,并根据各维度的隐私敏感度,自适应决定需添加的拉普拉斯噪声幅度,通过有效的噪声扰动方式实现差分隐私。通过与SLN(simple laplacion noise algorithm)算法ULN(uniform laplacian noise algorithm)算法相比较,仿真表明,MDLN算法的隐私保护强度较高,且效能更高。

关键词：实时监测系统拉普拉斯噪声多维分解差分隐私 MDLN算法

All roads lead to Rome-a review of the potential mechanisms by which exerkines exhibit neuroprotective effects in Alzheimer’s disease

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2022年第6期17卷 1210-1227页

作者： Yi-Yao Liang Li-Dan Zhang Xi Luo Li-Li Wu Zhao-Wei chen Guang-Hao Wei kai-Qing Zhang Ze-An Du Ren-Zhi Li Kwok-Fai So Ang Li Guangdong-Hong Kong-Macao Institute of CNS Regeneration Jinan UniversityGuangzhouGuangdong ProvinceChina Key Laboratory of CNS Regeneration(Jinan University) Ministry of EducationGuangzhouGuangdong ProvinceChina Department of Medical Ultrasonics Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Guangdong Key Laboratory of Liver Disease Research Sun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Department of Clinical Medicine School of MedicineJinan UniversityGuangzhouGuangdong ProvinceChina Department of Clinical Medicine International SchoolJinan UniversityGuangzhouGuangdong ProvinceChina International Department of the Affiliated High School of South China Normal University GuangzhouGuangdong ProvinceChina Bioland Laboratory(Guangzhou Regenerative Medicine and Health Guangdong Laboratory) GuangzhouGuangdong ProvinceChina Co-Innovation Center of Neuroregeneration Nantong UniversityNantongJiangsu ProvinceChina

Age-related neurodegenerative disorders such as Alzheimer’s disease(AD)have become a critical public health issue due to the significantly extended human lifespan,leading to considerable economic and social *** therapies for AD such as medicine and surgery remain ineffective,impractical,and *** studies have shown that a variety of bioactive substances released by physical exercise(called“exerkines”)help to maintain and improve the normal functions of the brain in terms of cognition,emotion,and psychomotor *** evidence suggests that exerkines may exert beneficial effects in AD as *** review summarizes the neuroprotective effects of exerkines in AD,focusing on the underlying molecular mechanism and the dynamic expression of exerkines after physical *** findings described in this review will help direct research into novel targets for the treatment of AD and develop customized exercise therapy for individuals of different ages,genders,and health conditions.

关键词： Alzheimer’s disease amyloid beta central nervous system exerkine neurodegeneration neuroinflammation neuroprotection oxidative stress physical exercise Tau protein