Preparation and Characteristic of Dextran-BSA Antibody and Establishment of it’s Elisa Immunoassay

The enzyme linked immunosorbent assay (ELISA) is a potential tool for the determination of dextran. In this study, dextran–BSA antigens were prepared by Reductive amination method, and were confirmed by SDS-PAGE and free amino detection. The effects of coupled reaction conditions such as different oxidation degree of dextran, the reaction time were investigated and the immunity of the resulting dextran- BSA neoglycoprotein antigens were evaluated through the interaction with standard dextran antibody. The immunogen was immunized with white rabbits to obtained polyclonal antibody respectively. A general and broad class-specific Elisa detection method was developed according to Elisa theory. The method was put to use for quantitative analysis of dextran in practical saccharose samples

Notch Signaling Activation Promotes Seizure Activity in Temporal Lobe Epilepsy

Notch signaling in the nervous system is often regarded as a developmental pathway. However, recent studies have suggested that Notch is associated with neuronal discharges. Here, focusing on temporal lobe epilepsy, we found that Notch signaling was activated in the kainic acid (KA)-induced epilepsy model and in human epileptogenic tissues. Using an acute model of seizures, we showed that DAPT, an inhibitor of Notch, inhibited ictal activity. In contrast, pretreatment with exogenous Jagged1 to elevate Notch signaling before KA application had proconvulsant effects. In vivo, we demonstrated that the impacts of activated Notch signaling on seizures can in part be attributed to the regulatory role of Notch signaling on excitatory synaptic activity in CA1 pyramidal neurons. In vitro, we found that DAPT treatment impaired synaptic vesicle endocytosis in cultured hippocampal neurons. Taken together, our findings suggest a correlation between aberrant Notch signaling and epileptic seizures. Notch signaling is up-regulated in response to seizure activity, and its activation further promotes neuronal excitation of CA1 pyramidal neurons in acute seizures

Construction of retroviral recombinant containing human tissue inhibitor of metalloproteinase-2 (TIMP-2) gene and spontaneous invasion of gastric carcinoma cell lines in vitro

Recombinant retroviral vector containing human tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) gene was constructed and investigation of the in vitro invasion and metastasis of gastric cancer cells transfected with TIMP-2 was carried out. Human TlMP-2 was isolated from recombinant vector Bluescript 1/TIMP-2(+), and then inserted into the retroviral vector pL-MT. Correct orientation was verified by restriction endonuclease digestion. Human full length TIMP-2 gene was ligated into a plasmid, which was then transfected into PA317 cell line. G418-resistant individual clones were selected to transfect human SGC-7901 cell line. Cell proliferation, cell electrophoresis, soft agar colony formation and in vitroinvasion were detected to analyze the bio-behavioral changes of cancer cells. The results from restriction endonuclease digestion were as theoretically expected. The cell electrophoresis rate, colony number and invasion ability in SGC-7901 cells and MFC cells transfected with TIMP-2 gene were significantly decreased when compared with control group. However, no significant changes were noted in the proliferation of cancer cells. We successfully construct a recombinant retroviral vector containinghuman TIMP-2. TIMP-2 transfection could markedly alter the membrane charge of cancer cells, resulting in decreased electrophoresis capacity, cell migration and invasion. However, cell growth was not affected by TIMP-2. These results suggested TIMP-2 transfection might exert effects on the malignant phenotype of cancer cells through affecting extracellular environment, which provided a new way to investigate gene regulation of in vitro collagen metabolism

Model the Relationship of NH3 Emission with Attributing Factors from Rice Fields in China: Ammonia Mitigation Potential Using a Urease Inhibitor

Substantial ammonia (NH3) losses from rice production result in poor nitrogen (N) use efficiency and environmental damage. A data synthesis using the published literature (127 studies with 700 paired observations), combined with an incubation experiment using 50 paddy soils from across China, were conducted to improve the current understanding of the NH3 loss from paddy rice and its drivers. The efficacy of the urease inhibitor Limus® for reducing NH3 losses was also evaluated. The mean loss of N, through NH3 volatilization, was 16.2% of the urea-N applied to paddy rice. The largest losses were from double rice cropping systems, and losses increased with the N application rate, surface application of N, unstable N types (ammonium bicarbonate and urea), and high floodwater pH. Under simulated flooded conditions, urea amended with Limus® reduced NH3 loss by 36.6%, compared to urea alone, but floodwater pH had a significant effect on inhibitor efficacy. Key driving factors were air temperature, N application rate, and floodwater pH. The effectiveness and limitations of the inhibitor in NH3 emission mitigation was examined, as well as its basis as one means of N pollution control in paddy rice cropping systems

A green eco-environment for sustainable development - framework and action

Following its 40-year reform and ‘Open Door’ policy, China has recently proposed a new approach to green development and rural revitalization—the idea of Agriculture Green Development (AGD), with the key feature of creating a green eco-environment. In this minireview we introduce the definition, theory, framework and major components of a green eco-environment as a key part of the AGD. We define a green eco-environment as including four key elements or measures: (1) a green ecoenvironmental indicator system; (2) environmental monitoring and warning networks; (3) emission standards and environmental thresholds for key pollutants; (4) emission controls and pollution remediation technologies. We have used Quzhou County (a typical county in the center of the North China Plain) as an example to show how detailed air, water and soil monitoring networks, as well as improved farmer practices and pollution control measures (especially ammonia emission mitigation and PM2.5 pollution reduction), can begin to create a green eco-environment in China and that AGD is possible. We conclude by stressing the need to improve the framework and practice for a green eco-environment, especially the importance of linking proposals and practices for a green eco-environment with the United Nations high priority Sustainable Development Goals

Spin Precession and Time-Reversal Symmetry Breaking in Quantum Transport of Electrons Through Mesoscopic Rings

We consider the motion of electrons through a mesoscopic ring in the presence of spin-orbit interaction, Zeeman coupling, and magnetic flux. The coupling between the spin and the orbital degrees of freedom results in the geometric and the dynamical phases associated with a cyclic evolution of spin state. Using a non-adiabatic Aharonov-Anandan phase approach, we obtain the exact solution of the system and identify the geometric and the dynamical phases for the energy eigenstates. Spin precession of electrons encircling the ring can lead to various interference phenomena such as oscillating persistent current and conductance. We investigate the transport properties of the ring connected to current leads to explore the roles of the time-reversal symmetry and its breaking therein with the spin degree of freedom being fully taken into account. We derive an exact expression for the transmission probability through the ring. We point out that the time-reversal symmetry breaking due to Zeeman coupling can totally invalidate the picture that spin precession results in effective, spin-dependent Aharonov-Bohm flux for interfering electrons. Actually, such a picture is only valid in the Aharonov-Casher effect induced by spin-orbit interaction only. Unfortunately, this point has not been realized in prior works on the transmission probability in the presence of both SO interaction and Zeeman coupling. We carry out numerical computation to illustrate the joint effects of spin-orbit interaction, Zeeman coupling and magnetic flux. By examining the resonant tunneling of electrons in the weak coupling limit, we establish a connection between the observable time-reversal symmetry breaking effects manifested by the persistent current and by the transmission probability. For a ring formed by two-dimensional electron gas, weComment: 20 pages, 5 figure

Highly Efficient Graphene-Based Optical Modulator With Edge Plasmonic Effect

We report a highly efficient graphene-based modulator by using an edge plasmonic effect in this paper. The modulation efficiency of the proposed modulator can be as large as 1.58 dB/μm, which is several times larger than that of previous reported modulators. By enhancing the gap plasmon mode and the edge plasmonic effect in a well-designed diagonal waveguide, a wedge-to-wedge SPP mode is strongly confined in both horizontal and vertical directions in terms of a small mode area (A_{ef}/A₀ < 1/1000), which significantly improves the light-graphene interaction. A large modulation efficiency of 4.05 dB/μm has been obtained after geometry optimization, which is the best values reported in our knowledge. The physical reason for the improvement is explored. We find the sharpness of the waveguide edges has strong impact on the field enhancement and modulation efficiency. Geometry optimization is made to further investigate the enhancement mechanisms and modulation capacities. Our results may promote the development of active nanophotonic devices incorporating two-dimensional materials

DESIGN OF THE SSR021 CAVITY FOR THE PROTON ACCELERATOR MAIN LINAC OF CHINA ADS*

Abstract China ADS is a high intensity proton machine based on CW superconducting technology. It includes two injectors and one main linac. The Institute of High Energy Physics (IHEP) and the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS), are responsible for developing the main linac together. This paper introduces the physics and mechanical design of the single spoke resonator (SSR021, beta021 cavity), which is used for first section of the main linac

Imaging and Dynamics of Light Atoms and Molecules on Graphene

Observing the individual building blocks of matter is one of the primary goals of microscopy. The invention of the scanning tunneling microscope [1] revolutionized experimental surface science in that atomic-scale features on a solid-state surface could finally be readily imaged. However, scanning tunneling microscopy has limited applicability due to restrictions, for example, in sample conductivity, cleanliness, and data aquisition rate. An older microscopy technique, that of transmission electron microscopy (TEM) [2, 3] has benefited tremendously in recent years from subtle instrumentation advances, and individual heavy (high atomic number) atoms can now be detected by TEM [4 - 7] even when embedded within a semiconductor material [8, 9]. However, detecting an individual low atomic number atom, for example carbon or even hydrogen, is still extremely challenging, if not impossible, via conventional TEM due to the very low contrast of light elements [2, 3, 10 - 12]. Here we demonstrate a means to observe, by conventional transmision electron microscopy, even the smallest atoms and molecules: On a clean single-layer graphene membrane, adsorbates such as atomic hydrogen and carbon can be seen as if they were suspended in free space. We directly image such individual adatoms, along with carbon chains and vacancies, and investigate their dynamics in real time. These techniques open a way to reveal dynamics of more complex chemical reactions or identify the atomic-scale structure of unknown adsorbates. In addition, the study of atomic scale defects in graphene may provide insights for nanoelectronic applications of this interesting material.Comment: 9 pages manuscript and figures, 9 pages supplementary informatio