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      • KCI등재

        Biomass of Bacterioplankton and Protists and Their Ecological Importance in the Bering Sea

        Jianfeng He,정경호,강성호,Bo Chen,Yinxin Zeng,Minghong Cai 한국해양과학기술원 2004 Ocean and Polar Research Vol.26 No.2

        The abundance, biomass and distribution of phytoplankton, bacterioplankton and heterotrophic protists in the Bering Sea were investigated from July to August 1999. Chlorophyll a concentrations in the surface waters ranged from 0.16 to 3.79 mg l-1. Nano-phytoplankton were found to constitute from 63 to 98% of the total phytoplankton biomass, and were clearly the dominant primary producers. The biomass of bacterioplankton in the surface layers varied from 1.46 to 20.2 mg C l-1 and accounted for 30% of the total phytoplankton biomass. The biomass of bacterioplankton integrated over a depth of 0 to 100 m averaged 65.4% of the total phytoplankton biomass. The surface biomass of heterotrophic protists ranged from 1.2 to 27.4 mg C l-1, and was within the same order of magnitude as that of bacterioplankton. Of the total biomass of heterotrophic protists in the upper 100 m of the water column, 65% was attributed to protists in the nano-size class. The results of this study suggest that bacteria and nano-protists are important components of the planktonic community in the Bering Sea during the summer season. The abundance of bacterioplankton and planktonic protists decreased from the western to northeastern and eastern regions of the Bering Sea. The abundance of these organisms also decreased with depth. The available evidence suggests that variation in the abundance and distribution of these organisms may be affected by water currents and vertical temperature variation in the Bering Sea.

      • KCI등재

        Laparoscopic surgery contributes to a decrease in short-term complications in surgical ulcerative colitis patients during 2008–2017: a multicenter retrospective study in China

        Zerong Cai,Xiaosheng He,Jianfeng Gong,Peng Du,Wenjian Meng,Wei Zhou,Jinbo Jiang,Bin Wu,Weitang Yuan,Qi Xue,Lianwen Yuan,Jinhai Wang,Jiandong Tai,Jie Liang,Weiming Zhu,Ping Lan,Xiaojian Wu 대한장연구학회 2023 Intestinal Research Vol.21 No.2

        Background/Aims: The aim of this study was to analyze the chronological changes in postoperative complications in surgical ulcerative colitis patients over the past decade in China and to investigate the potential parameters that contributed to the changes. Methods: Ulcerative colitis patients who underwent surgery during 2008–2017 were retrospectively enrolled from 13 hospitals in China. Postoperative complications were compared among different operation years. Risk factors for complications were identified by logistic regression analysis. Results: A total of 446 surgical ulcerative colitis patients were analyzed. Fewer short-term complications (24.8% vs. 41.0%, P=0.001) and more laparoscopic surgeries (66.4% vs. 25.0%, P<0.001) were found among patients who received surgery during 2014–2017 than 2008–2013. Logistic regression suggested that independent protective factors against short-term complications were a higher preoperative body mass index (odds ratio [OR], 0.870; 95% confidence interval [CI], 0.785–0.964; P=0.008), laparoscopic surgery (OR, 0.391; 95% CI, 0.217–0.705; P=0.002) and elective surgery (OR, 0.213; 95% CI, 0.067–0.675; P=0.009). The chronological decrease in short-term complications was associated with an increase in laparoscopic surgery. Conclusions: Our data revealed a downward trend of short-term postoperative complications among surgical ulcerative colitis patients in China during the past decade, which may be due to the promotion of minimally invasive techniques among Chinese surgeons.

      • KCI등재

        Nonlinear stability analysis of a radially retractable hybrid grid shell in the closed position

        Jianguo Cai,Qian Zhang,Youbao Jiang,Yixiang Xu,Jianfeng Zhao,Xiaowei Deng 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.24 No.3

        The buckling capacity of a radially retractable hybrid grid shell in the closed position was investigated in this paper. The geometrically non-linear elastic buckling and elasto-plastic buckling analyses of the hybrid structure were carried out. A parametric study was done to investigate the effects rise-to-span ratio, beam section, area and pre-stress of cables, on the failure load. Also, the influence of the shape and scale of imperfections on the elasto-plastic buckling loads was discussed. The results show that the critical buckling load is reduced by taking account of material non-linearity. Furthermore, increasing the rise-tospan ratio or the cross-section area of steel beams notably improves the stability of the structure. However, the cross section area and pre-stress of cables pose negligible effect on the structural stability. It can also be found that the hybrid structure is highly sensitive to geometric imperfection which will considerably reduce the failure load. The proper shape and scale of the imperfection are also important.

      • KCI등재

        Structural evaluation of a foldable cable-strut structure for kinematic roofs

        Jianguo Cai,Qian Zhang,Yiqun Zhang,Daniel Sang-hoon Lee,Jianfeng Zhao 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.29 No.5

        The rapidly decreasing natural resources and the global variation of the climate push us to find intelligent and efficient structural systems to provide more people with fewer resources. This paper proposed a kinematic cable-strut system to realize sustainable structures in responding to changing environmental conditions. At first, the concept of the kinematic system based on crystal-cell pyramid (CP) cable-strut unit was given. Then the deployment of the structure was studied experimentally. After that, the static behaviors in the fully deployed state under the symmetric and asymmetric load cases were investigated. Moreover, the effects of thermal loading and the initial prestress distribution were also discussed. Comparative studies between the proposed structure and other deployable cable-strut system under three times of design load cases were carried out. Finally, the robustness of the system was studied by removal of one passive cable at one time.

      • KCI등재

        Static analysis of a radially retractable hybrid grid shell in the closed position

        Jianguo Cai,Chao Jiang,Xiaowei Deng,Jianfeng Zhao,Yixiang Xu 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.18 No.6

        A radially retractable roof structure based on the concept of the hybrid grid shell is proposed in this paper. The single-layer steel trusses of the radially foldable bar structure are diagonally stiffened by cables, which leads to a single-layer lattice shell with triangular mesh. Then comparison between the static behavior between the retractable hybrid grid shell and the corresponding foldable bar shell with quadrangular mesh is discussed. Moreover, the effects of different structural parameters, such as the rise-to-span ratio, the bar cross section area and the pre-stress of the cables, on the structural behaviors are investigated. The results show that prestressed cables can strengthen the foldable bar shell with quadrangular mesh. Higher structural stiffness is anticipated by introducing cables into the hybrid system. When the rise-span ratio is equal to 0.2, where the joint displacement reaches the minimal value, the structure shape of the hyrbid grid shell approaches the reasonable arch axis. The increase of the section of steel bars contributes a lot to the integrity stiffness of the structure. Increasing cable sections would enhance the structure stiffness, but it contributes little to axial forces in structural members. And the level of cable prestress has slight influence on the joint displacements and member forces.

      • SCOPUSKCI등재

        Biomass of Bacterioplankton and Protists and Their Ecological Importance in the Bering Sea

        He, Jianfeng,Chen, Bo,Kang, Sung-Ho,Zeng, Yinxin,Cai, Minghong Korea Institute of Ocean ScienceTechnology 2004 Ocean and Polar Research Vol.26 No.2

        The abundance, biomass and distribution of phytoplankton, bacterioplankton and heterotrophic protists in the Bering Sea were investigated from July to August 1999. Chlorophyll a concentrations in the surface waters ranged from 0.16 to $3.79{\mu}g\;l^{-1}$ Nano-phytoplankton were found to constitute from 63 to 98% of the total phytoplankton biomass, and were clearly the dominant primary producers. The biomass of bacterioplankton in the surface layers varied from 1.46 to $20.2{\mu}g\;C\;l^{-1}$ and accounted for 30% of the total phytoplankton biomass. The biomass of bacterioplankton integrated over a depth of 0 to 100m averaged 65.4% of the total phytoplankton biomass. The surface biomass of heterotrophic protists ranged from 1.2 to $27.4{\mu}g\;C\;l^{-1}$, and was within the same order of magnitude as that of bacterioplankton. Of the total biomass of heterotrophic protists in the upper 100m of the water column, 65% was attributed to protists in the nano-size class. The results of this study suggest that bacteria and nano-protists are important components of the planktonic community in the Bering Sea during the summer season. The abundance of bacterioplankton and planktonic protists decreased from the western to northeastern and eastern regions of the Bering Sea. The abundance of these organisms also decreased with depth. The available evidence suggests that variation in the abundance and distribution of these organisms may be affected by water currents and vertical temperature variation in the Bering Sea.

      • KCI등재

        Efficient Expression and Purification of Recombinant Alcohol Oxidase in Pichia pastoris

        Yunping Liu,Jianfeng Pan,Peilian Wei,Jianzhong Zhu,Lei Huang,Jin Cai,Zhinan Xu 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.4

        In order to improve the production of alcohol oxidase (AOX), a recombinant Pichia pastoris (P. pastoris)system was constructed by transformation of the plasmid pPIC9K-AOX into P. pastoris GS115. The effects of different expression conditions on alcohol oxidase activity in the culture supernatant were investigated in the shake flask scale. The results showed that the highest extracellular activity (562 U/L) of alcohol oxidase was obtained after 56h induction with 4% methanol at OD600 1.0 in the medium containing 50 g/L maltose, which is about 4.2 folds higher than previously reported. High-purity functional recombinant AOX (>90%) was purified from the culture with the Ni-NTA affinity column and Sephadex G-100 chromatographical methods, with a total recovery rate of 68.9%. Further studies showed that the purified rAOX had similar enzymatic characteristics as the native enzyme, except that the thermal stability and resistance to H2O2 inhibition of rAOX were significantly greater compared to the previous report. The purified rAOX was well tolerant to various water-miscible organic solvents. This efficient expression and purification process will be promising for large-scale production of rAOX as an important diagnostic enzyme for alcohol detection in many areas.

      • Snapshot of Technology Business Incubators in China

        Nasir Mahmood,Cai Jianfeng,Farhan Jamil,Hina Munir,Jintao LU,Mustafa Khan,Yue Cai 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.7

        In the contemporary world, the production of suitable goods and commodities and business developments, the business technology incubators are considered important for the inception of new ideas and combining them with the available resources. Similarly, business and technology incubators are considered a backbone to accelerate the innovation and new business development structure of national economies. The business incubators in China are flourishing by leaps and bounds since the mid of 1990s. This paper aims to explore the performance of technology business incubator in china. In this study the incubator data which was compiled by Ministry of Science and Technology (MOST) China was taken for performance evaluation in china. The performance of incubator in 2002 and in 2012 was assessed by comparison of total number of tenants, total income of tenants, number of graduated tenants and number of employees of tenants, further, in 2012 the association of number of invention patent with the accumulated number of tenants obtained investment and finance is assessed, and this paper also presents the graduated firms number every year in China. These results show that the performance of technology incubators is increased during the last decade.

      • The Role of University-Based Incubators in Developing Economies: Empirical Evidence from Pakistan

        Nasir Mahmood,Cai Jianfeng,Hina Munir,Farhan Jamil,Anum Nusrat 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.11

        Business incubators are an attractive tool for the economic development and support to nascent business in critical stages of their business life cycle. UBIs have a main featured to facilitate business tangible & intangible services such as access to research labs, office and network pool of different firms to build up nascent business. The aim of this paper, define the important role of UBIs have ability to support developing economies by providing talent from inside the university. UBIs also generate new resources and opportunities for innovation of products, creation of employment and leadership that play a key role in developing economies. In this paper the questionnaire survey used to know about the detailed information about the UBI. The results of this study give help to decision makers in university, industry and government for the growth of economy.

      • Impact of Factors that Inhibit the Drive of Entrepreneurship in Pakistan: Empirical Evidence from Young Entrepreneurs and Students

        Nasir Mahmood,Cai Jianfeng,Hina Munir,Nosheena Yasir 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.12

        Nowadays, in the era of competitiveness, competition, innovation and development of a country cannot be achieved without the successful entrepreneurial process. The current research is intended to elaborate the factors that obstruct the drive of entrepreneurship in Pakistan. For this purpose a quantitative survey was conducted in order to examine the six factors: lack of education and skills, terrorism, social status, political environment, lack of financial resources and business environment with motivation of entrepreneurship. Data was collected through questionnaire using simple random sampling technique from the young businessmen and students from the 3 cities of Pakistan which includes Lahore, Gujranwala and Islamabad. For the purpose of the analysis the sample of 250 were selected out of which 200 questionnaires which show the response rate is 80%. Analysis was run by using SPSS 19 and results showed that the factors including lack of education and skills, terrorism, social status, political environment, lack of financial resources and business environment have significant relation with the motivation of entrepreneurship in Pakistan. The current study has provided valuable information and recommendation to government, financial institutions, socialists and potential entrepreneurs to improve the culture of entrepreneurship in Pakistan.

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