China is becoming a leading nation in terms of its share of the world's publications in the emerging nanotechnology domain. This paper demonstrates that the international rise of China's position in nanotechnology has been underwritten by the emergence of a series of regional hubs of nanotechnology R&D activity within the country. We develop a unique database of Chinese nanotechnology articles covering the period 1990 to mid-2006 to identify the regional distribution of nanotechnology research in China. To build this database, a new approach was developed to clean and standardize the geographical allocation of Chinese publication records. We then analyze the data to understand the regional development of nanotechnology research in China over our study period and to map interregional and international research collaboration linkages. We find that the geographical distribution of China's domestic nanotechnology research is characterized by regional imbalance, with most of the leading regions located in eastern China, including not only Beijing and Shanghai but also a series of other new regional hubs. There is much less development of nanotechnology research in central and western China. Beijing, Shanghai, and Hong Kong are among the leading Chinese regions for international nanotechnology research collaboration. Other Chinese nanotechnology regions are less focused on international collaboration, although they have developed domestic interregional collaborations. Although new regional research hubs have emerged in the nanotechnology domain, the paper notes that their concentration in eastern China reinforces existing imbalances in science and technology capabilities in China, and in turn this may further reinforce the dominant position of eastern China in the commercialization of new technologies such as nanotechnology.
This paper examines the rapid growth of China in the field of nanotechnology and the rise of collaboration between China and the US in this emerging domain. Chinese scientific papers in nanotechnology are analyzed to indicate overall trends, leading fields and the most prolific institutions. Patterns of China–US nanotechnology paper co-authorship are examined over the period 1990–2009, with an analysis of how these patterns have changed over time. The paper combines bibliometric analysis and science mapping. We find rapid development in the number of China–US co-authored nanotechnology papers as well as structural changes in array of collaborative nanotechnology sub-fields. Implications for both China and the US of this evolving relationship are discussed.
Authorship identity has long been an Achilles’ heel in bibliometric analyses at the individual level. This problem appears
in studies of scientists’ productivity, inventor mobility and scientific collaboration. Using the concepts of cognitive maps
from psychology and approximate structural equivalence from network analysis, we develop a novel algorithm for name disambiguation
based on knowledge homogeneity scores. We test it on two cases, and the results show that this approach outperforms other
common authorship identification methods with the ASE method providing a relatively simple algorithm that yields higher levels
of accuracy with reasonable time demands.
There are many reactions of interest in which one or more of the reactants belong to some solid phases. Modern thermoanalytical instruments can conveniently provide reaction kinetic data of high precision and accuracy, from which the underlying activation energyE may be derived in principle. Unfortunately, no ‘best' method yet exists for the derivation when the data have been collected with a programmed linear increase in sample temperature, unlike the case of isothermal measurements, which however suffer from experimental limitations . Here we propose a method for extractingE from non-isothermal data, that promises general validity.
Authors:Yigang Xu, Xiaolin Zong, Bing Han, Yijing Li and Lijie Tang
In this study, Lactobacillus pentosus expressing porcine lactoferrin (pLF) was tested for in vitro antibacterial activity and for its ability to enhance immunity induced by an orally administered Aujeszky’s disease virus (ADV) vaccine. The cDNA encoding N-terminus of pLF was cloned into a Lactobacillus-specific plasmid to produce L. pentosus pLF expressing transformants (pPG612.1-pLFN/ L. pentosus). The antimicrobial activity of the recombinant pLF protein inhibited bacterial growth in vitro. The supernatant of pPG612.1-pLF-N/L. pentosus had an inhibitory effect on Staphylococcus aureus strain CVCC26003, Bacillus subtilis strain CVCC63501, Escherichia coli strain CVCC10141 and Salmonella enterica ssp. entericaCholeraesuis strain CVCC79102, while it did not inhibit the growth of Lactobacillus casei strain ATCC393. A mouse model was established to test the effectiveness of the orally administered probiotic L. pentosus recombinant strain in the gastrointestinal tract. Mice were immunised with an attenuated porcine Aujeszky’s disease virus (ADV) vaccine. Serum antibody levels determined using a mouse Aujeszky’s disease IgG ELISA showed that IgG levels were significantly higher in the pPG612.1-pLFN/L. pentosus group than in the PBS and Lactobacillus pentosus groups at days 7 and 21 (P < 0.01) and at day 14 (P < 0.05), indicating that this oral recombinant strain can improve the effectiveness of the vaccine and play a role in immune enhancement through humoral immunity. These results suggest that the recombinant Lactobacillus pentosus not only has the beneficial characteristics of lactic acid bacteria but also produces biologically functional lactoferrin.
Liquid crystalline polymer/polyamide 66 (LCP/PA66) and LCP/poly(butyl terephthalate) (LCP/PBT) blends were compounded using
a Brabender Plasticorder equipped with a mixing chamber. The LCP employed was a semi-flexible liquid crystalline copolyesteramide
based on 30 mol% of p-amino benzoic acid (ABA) and 70 mol% of poly(ethylene terephthalate) (PET). The Flory-Huggins interaction parameters (χ12)
of the LCP/ PA66 and LCP/PBT blends are estimated by melting point depression from DSC measurement. The results indicate that
c12 values all are negative for LCP/PA66 and LCP/PBT blends, and when the LCP content in these blends is more than 10 mass%,
the absolute value of χ12 decreases. Thereby, we can conclude that LCP/PA66 and LCP/PBT blends are fully miscible in the molten state, the molecular
interaction between the LCP and PA66 is stronger than that between LCP and PBT. As the LCP content in LCP/PA66 and LCP/PBT
blends is more than 10 mass%, the molecular interaction between LCP and matrix polymer decreases.
Authors:Z. Chen, S. Wang, J. Tang, X. Li, C. Liu, X. Xu and G. Cao
To provide a convenient and facile method to evaluate the radiochemical purity (RCP) of 99mTc-TRODAT-1 in quality control of routine clinical application, a simplified method of single-strip thin layer chromatography
(TLC) was developed and validated by high performance liquid chromatography (HPLC). The RCP data of TLC correlated well with
Authors:Yu Runlan, Guo Jingru, Cui Anzhi, Tang Peijia, Li Daming and Liu Daming
The half-life of79Se, a long-lived fission product nuclide, has never been measured accurately. The value quoted in the literature is an upper limit, 6.5·104 y, measured in 1949. In the present work we measured accurately the half-life of79Se to be (4.8±0.4)·105 y using a radiochemical method.
Authors:Zhao Xin, Li Xueliang, Guo Jingru, Wang Fangding, Tang Peijia, Liu Daming, Cui Anzhi and Su Shuxin
The cumulative yields of127gSn and128Sn in the region near symmetry for the spontaneous fission of252Cf have been measured by a radiochemical method for the first time. The yield values are (0.0437 ±0.0021)·10–2 and (0.182±0.009)·10–2, respectively. The cumulative yield of128Sn measured in this work is compared with those predicted based on WAHL's empirical Zp and Ap' models. The measured value is higher than both predictions, values 0.164·10–2 from the Zp model, and 0.144·10–2 on the basis of Ap' models.
Authors:S. Tang, L. Li, Q.Y. Zhou, W.Z. Liu, H.X. Zhang, W. Z. Chen and Y.F. Ding
Gibberellins (GAs) are a class of plant hormones that play important roles in diverse aspects during plant growth and development. A series of GA synthesis and metabolism genes have been reported or proved to have essential functions in different plant species, while a small number of GA 2-oxidase genes have been cloned or reported in wheat. Previous studies have provided some important findings on the process of GA biosynthesis and the enzymes involved in its related pathways. These may facilitate understanding of the complicated process underlying GA synthesis and metabolism in wheat. In this study, GA 2-oxidase genes TaGA2ox1-1, TaGA2ox1-2, TaGA2ox1-3, TaGA2ox1-4, TaGA2ox1-5, and TaGA2ox1-6 were identified and further overexpressed in rice plants to investigate their functions in GA biosynthesis and signaling pathway. Results showed overexpression of GA 2-oxidase genes in rice disrupted the GA metabolic pathways and induced catalytic responses and regulated other GA biosynthesis and signaling pathway genes, which further leading to GA signaling disorders and diversity in phenotypic changes in rice plants.