从金属纳米颗粒的理化性质以及生物吸收动力学角度探究金属纳米颗粒对水生生物的毒性     

Jian WANG Wen-xiong WANG 《浙江大学学报(A卷英文版)》2014,15(8):573-592

研究目的：研究金属纳米颗粒在进入水体后的一系列动力学过程对金属纳米颗粒的生物可利用性和毒性可能产生的影响。研究方法：针对在毒性测试中金属纳米颗粒的解析现象,选取三种常见的金属纳米颗粒（纳米氧化锌、纳米银和纳米二氧化钛）,总结了它们在毒性测试中的解析动力学、溶解性以及毒性。同时,综合水生生物对金属纳米颗粒以及离子的吸收动力学,利用动态模型进行模拟,阐述解离的离子在生物对金属纳米颗粒吸收中的贡献。重要结论：在评价金属纳米颗粒和解析离子对水生生物的生物利用度和毒性的测试过程中,需要综合考虑金属纳米颗粒的理化性质以及生物吸收动力学过程。  相似文献   

试论贫困学生问题的解决与和谐校园的构建     

赵政一 《教育与职业》2007,1(18):171-172

随着高校收费制度的改革,大学生中出现一个特殊的群体--贫困学生,他们面临着诸多问题.这些问题的存在,不仅关系到他们今后的成才和发展,也严重影响了和谐校园的构建.为此,我们必须高度关注和解决贫困学生问题,全面落实"以人为本"的科学发展观,努力打造温馨、舒适、愉快、稳定的校园环境,促进和谐校园的构建.  相似文献   

Pressure observer based adaptive robust trajectory tracking control of a parallel manipulator driven by pneumatic muscles     

ZHU Xiao-cong TAO Guo-liang CAO Jian 《浙江大学学报(A卷英文版)》2007,8(12):1928-1937

This paper presents a pressure observer based adaptive robust controller (POARC) for posture trajectory tracking of a parallel manipulator driven by three pneumatic muscles without pressure sensors. Due to model errors of the static forces and friction forces of pneumatic muscles, simplified average flow rate characteristics of valves, unknown disturbances of entire system, and unmeasured pressures, there exist rather severe parametric uncertainties, nonlinear uncertainties and dynamic uncertainties in modeling of the parallel manipulator. A nonlinear pressure observer is constructed to estimate unknown pressures on the basis of a single-input-single-output (SISO) decoupling model that is simplified from the actual multiple-input-multiple-output (MIMO) coupling model of the parallel manipulator. Then, an adaptive robust controller integrated with the pressure observer is developed to accomplish high precision posture trajectory tracking of the parallel manipulator. The experimental results indicate that the system with the proposed POARC not only achieves good control accuracy and smooth movement but also maintains robustness to disturbances.  相似文献   

Study on the expression and mutation of human telomeric repeat binding factor （hTRF1） in 10 malignant hematopoietic cell lines     

SUN Jie 《Journal of Zhejiang University. Science. B》2005,6(12):1141-1147

Objective: Detecting the expression and mutation of human telomeric repeat binding factor (hTRF1) in 10 malignant hematopoietic cell line cells on the base of determining its genomic structure and its four pseudogenes to clarify if h TRF1 mutation is one of the factors of the activation oftelomerase. Methods: hTRF1cDNA sequences were obtained from GenBank, its genome structure and pseudogenes were forecasted by BLAST and other biology information programs and then testified by sequencing.Real-time RT-PCR was used to detect the expression ofhTRF1mRNA in 10 cell line cells, including myelogenous leukemia cell lines K562, HL-60, U-937, NB4, THP-1, HEL and Dami; lymphoblastic leukemia cell lines 6T-CEM, Jurkat and Raji. Telomerase activities of cells were detected by using telomeric repeat amplification (TRAP)-ELISA protocol. PCR and sequencing were used to detect mutation of each exon of h TRF1 in 10 cell line cells. Results: h TRF1 gene, mapped to 8q 13, was divided into 10 exons and spans 38.6 kb. Four processed pseudogenes of hTRF1 located on chromosome 13, 18, 21 and X respectively, was named as ψhTRF1-13, ψhTRF1-18, ψhTRF1-21 and ψhTRF1-X respectively. All cell line cells showed positive telomerase activity. The expression of hTRF1 was significantly lower in malignant hematopoietic cell lines cells (0.0338, 0.0108～0.0749) than in normal mononuclear cells (0.0493, 0.0369～0.128) (P=0.004). But no significant mutation was found in all exons of hTRF1 in 10 cell line cells. Four variants were found in part of intron 1,2 and 8 ofhTRF1. Their infection on gene function is unknown and needs further studies. Conclusion: hTRF1 mutation is probably not one of the main factors for telomerase activation in malignant hematopoietic disease.  相似文献   

A three-level mobility management scheme for hierarchical mobile IPv6 networks     

WAN Zheng PAN Xue-zeng CHEN Jian CUI Yu-zeng 《浙江大学学报(A卷英文版)》2006,7(12):2118-2126

INTRODUCTION Mobile IPv6 (MIPv6) (Johnson et al., 2004) was proposed to maintain network connectivity in the next generation Internet. However, communication quality of MIPv6 degrades because of the high signaling overhead and the long signaling delay when a mobile node (MN) performs handover. Hierarchical Mobile IPv6 (HMIPv6) (Soliman et al., 2005) was proposed to improve the performance of MIPv6, where the Mobility Anchor Point (MAP) handles mobility in- side the local domain…  相似文献   

How variable progenitor clones construct a largely invariant neocortexOA     

Zhongfu Shen  Jiajun Yang  Qiangqiang Zhang  Kuiyu Wang  Xiaohui Lv  Xiaolin Hu  Jian Ma  Song-Hai Shi 《国家科学评论(英文版)》2024,(1):129-144

The neocortex contains a vast collection of diverse neurons organized into distinct layers. While nearly all neocortical neurons are generated by radial glial progenitors(RGPs), it remains largely unclear how a complex yet organized neocortex is constructed reliably and robustly. Here, we show that the division behavior and neuronal output of RGPs are highly constrained with patterned variabilities to support the reliable and robust construction of the mouse neocortex. The neurogenic process of ...  相似文献   

A novel mutation in CD40 ligand gene in a sporadic patient with hyper-IgM syndrome     

Sun Jian 《上海大学学报(英文版)》1998,2(2):164-169

１ＩｎｔｒｏｄｕｃｔｉｏｎＨｙｐｅｒ－ＩｇＭｓｙｎｄｒｏｍｅ（ＨＩＭ）ｉｓａｒａｒｅｉｍｍｕｎｏｄｅｆｉｃｉｅｎｃｙｃｈａｒａｃｔｅｒｉｚｅｄｂｙａｎｉｎｃｒｅａｓｅｄｓｕｓｃｅｐｔｉｂｉｌｉｔｙｔｏｒｅｃｕｒｒｅｎｔｉｎｆｅｃｔｉｏｎｓａｎｄｍａｒ...  相似文献   

ReinforcementBased Fuzzy Neural Network Control with Automatic Rule Generation     

WU Geng feng DONG Jian quan CHEN Yi min CAO Min ZHANG Yue 《上海大学学报(英文版)》1999,3(4):282-286

１　Ｉｎｔｒｏｄｕｃｔｉｏｎ　Ａｆｕｚｚｙｎｅｕｒａｌｎｅｔｗｏｒｋｃｏｎｔｒｏｌｌｅｒｂａｓｅｄｏｎｔｈｅｃｏｍｂｉｎａｔｉｏｎｏｆｆｕｚｚｙｌｏｇｉｃｓｙｓｔｅｍａｎｄｎｅｕｒａｌｎｅｔｗｏｒｋｈａｓｕｎｉｑｕｅｃｈａｒａｃｔｅｒｉｓｔｉｃｓ．Ｉｔｎｏｔｏｎｌｙｈａｓｔｈｅｆｕｎｃｔｉｏｎｏｆｌｅａｒｎｉｎｇａｎｄａｓｓｏｃｉａｔｉｖｅｍｅｍｏｒｙｂｕｔａｌｓｏｃｌｅａｒｌｙｒｅｐｒｅｓｅｎｔｓａｋｉｎｄｏｆｓｔｒｕｃｔｕｒｅｄｋｎｏｗｌｅｄｇｅａｎｄｄｏｅｓｆｕｚｚｙｉｎｆｅｒｅｎ…  相似文献   

Warming-induced phenological mismatch between trees and shrubs explains high-elevation forest expansion     

Xiaoxia Li  Eryuan Liang  J.Julio Camarero  Sergio Rossi  Jingtian Zhang  Haifeng Zhu  Yongshuo H.Fu  Jian Sun  Tao Wang  Shilong Piao  Josep Pe?uelas 《国家科学评论(英文版)》2023,(10):62-71

Despite the importance of species interaction in modulating the range shifts of plants,little is known about the responses of coexisting life forms to a warmer climate.Here,we combine long-term monitoring of cambial phenology in sympatric trees and shrubs at two treelines of the Tibetan Plateau,with a meta-analysis of ring-width series from 344 shrubs and 575 trees paired across 11 alpine treelines in the Northern Hemisphere.Under a spring warming of +1℃,xylem resumption advances by 2-4 days in ...  相似文献   

Reactant enrichment in hollow void of Pt NPs@MnOx nanoreactors for boosting hydrogenation performance     

Yanfu Ma  Liwei Wang  Wantong Zhao  Tianyi Liu  Haitao Li  Wenhao Luo  Qike Jiang  Wei Liu  Qihua Yang  Jun Huang  Riguang Zhang  Jian Liu  G.Q.Max Lu  Can Li 《国家科学评论(英文版)》2023,(10):114-122

In confined mesoscopic spaces,the unraveling of a catalytic mechanism with complex mass transfer and adsorption processes such as reactant enrichment is a great challenge.In this study,a hollow nanoarchitecture of MnO_x-encapsulated Pt nanoparticles was designed as a nanoreactor to investigate the reactant enrichment in a mesoscopic hollow void.By employing advanced characterization techniques,we found that the reactant-enrichment behavior is derived from directional diffusion of the r...  相似文献