50 results on '"D. D. Niu"'
Search Results
2. [Multi-state Markov model analysis of disease outcomes and influencing factors in HIV infected individuals receiving antiretroviral therapy in Luzhou of Sichuan province, 2010-2021]
- Author
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D D, Niu, H L, Tang, F F, Chen, T C, Xiao, C, Chen, H, Liu, and P, Lyu
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Adult ,China ,Young Adult ,Adolescent ,Disease Progression ,Humans ,HIV Infections ,Middle Aged ,CD4 Lymphocyte Count ,Retrospective Studies - Published
- 2022
3. Hydrogen and helium escape on Venus via energy transfer from hot oxygen atoms
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Jun Cui, D.-D. Niu, Jiang Yu, and H. Gu
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Physics ,010504 meteorology & atmospheric sciences ,biology ,Hydrogen ,Energy transfer ,chemistry.chemical_element ,Astronomy and Astrophysics ,Venus ,biology.organism_classification ,01 natural sciences ,Oxygen atom ,chemistry ,Space and Planetary Science ,0103 physical sciences ,Astrophysics::Earth and Planetary Astrophysics ,Atomic physics ,010303 astronomy & astrophysics ,Helium ,0105 earth and related environmental sciences - Abstract
Due to the relatively strong gravity on Venus, heavy atmospheric neutrals are difficult to accelerate to the escape velocity. However, a variety of processes, such as the dissociative recombination of ionospheric O$_2^+$, are able to produce hot atoms which could deliver a significant amount of energy to light neutrals and drive their escape. In this study, we construct a Monte Carlo model to simulate atmospheric escape of three light species, H, H2, and He, on Venus via such a knock-on process. Two Venusian background atmosphere models are adopted, appropriate for solar minimum and maximum conditions. Various energy-dependent and species-dependent cross-sections, along with a common strongly forward scattering angle distribution, are used in our calculations. Our model results suggest that knock-on by hot O likely plays the dominant role in driving total atmospheric hydrogen and helium escape on Venus at the present epoch, with a significant portion contributed from regions below the exobase. Substantial variations are also revealed by our calculations. Of special interest is the modelled reduction in escape flux at high solar activities for all species, mainly associated with the enhancement in thermal O concentration near the exobase at high solar activities which hinders escape. Finally, model uncertainties due to several controlling factors, including the distribution of relevant light species in the background atmosphere, the plane-parallel approximation, and the finite O energy distribution, are evaluated.
- Published
- 2020
4. Observation of CO2++ dication in the dayside Martian upper atmosphere
- Author
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Yongqiang Hao, Yong Wei, XiaoShu Wu, JianPing Huang, LongKang Dai, D.-D. Niu, H. Gu, and Jun Cui
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Martian ,Physics ,Atmospheric Science ,Astronomy and Astrophysics ,Atmosphere of Mars ,Photoionization ,Mass spectrometry ,Dissociation (chemistry) ,Ion ,Dication ,On board ,Space and Planetary Science ,Physics::Space Physics ,Astrophysics::Earth and Planetary Astrophysics ,Atomic physics ,Physics::Atmospheric and Oceanic Physics - Abstract
Doubly charged positive ions (dications) are an important component of planetary ionospheres because of the large energy required for their formation. Observations of these ions are exceptionally difficult due to their low abundances; until now, only atomic dications have been detected. The Neutral Gas and Ion Mass Spectrometer (NGIMS) measurements made on board the recent Mars Atmosphere and Volatile Evolution mission provide the first opportunity for decisive detection of molecular dications, CO2++ in this case, in a planetary upper atmosphere. The NGIMS data reveal a dayside averaged CO2++ distribution declining steadily from 5.6 cm−3 at 160 km to below 1 cm−3 above 200 km. The dominant CO2++ production mechanisms are double photoionization of CO2 below 190 km and single photoionization of CO2+ at higher altitudes; CO2++ destruction is dominated by natural dissociation, but reactions with atmospheric CO2 and O become important below 160 km. Simplified photochemical model calculations are carried out and reasonably reproduce the data at low altitudes within a factor of 2 but underestimate the data at high altitudes by a factor of 4. Finally, we report a much stronger solar control of the CO2++ density than of the CO2+ density .
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- 2020
5. Species‐dependent Response of the Martian Ionosphere to the 2018 Global Dust Event
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T. L. Zhang, S.-Q. Wu, Mingyu Wu, H. Gu, Jiahao Zhong, Y. ‐T. Cao, D.-D. Niu, Jun Cui, Xutong Wu, Yong Wei, and Zhaopeng Wu
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Martian ,Geophysics ,Space and Planetary Science ,Geochemistry and Petrology ,Event (relativity) ,Earth and Planetary Sciences (miscellaneous) ,Environmental science ,Mars Exploration Program ,Ionosphere ,Astrobiology - Published
- 2021
6. A Survey of Photoelectrons on the Nightside of Mars
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Y. ‐T. Cao, H. R. Lai, D.-D. Niu, Jun Cui, Xutong Wu, Yong Wei, Binbin Ni, J. Yu, and Qiong Luo
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Physics ,Geophysics ,General Earth and Planetary Sciences ,Mars Exploration Program ,Photoelectric effect ,Astrobiology - Published
- 2021
7. Is Solar Wind electron precipitation a source of neutral heating in the nightside Martian upper atmosphere?
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XiaoShu Wu, Jun Cui, LongKang Dai, YuTian Cao, H. R. Lai, H. Gu, and D.-D. Niu
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Atmosphere ,Martian ,Atmospheric Science ,Solar wind ,Space and Planetary Science ,Thermal ,Coronal mass ejection ,Environmental science ,Electron precipitation ,Astronomy and Astrophysics ,Atmosphere of Mars ,Interplanetary spaceflight ,Atmospheric sciences - Abstract
Solar Wind (SW) electron precipitation is able to deposit a substantial amount of energy in the nightside Martian upper atmosphere, potentially exerting an influence on its thermal structure. This study serves as the first investigation of such an issue, with the aid of the simultaneous measurements of both neutral density and energetic electron intensity made on board the recent Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft. We report that, from a statistical point of view, the existing measurements do not support a scenario of noticeable neutral heating via SW electron precipitation. However, during 3%−4% of the MAVEN orbits for which data are available, strong correlation between nightside temperature and electron intensity is observed, manifested as collocated enhancements in both parameters, as compared to the surrounding regions. In addition, our analysis also indicates that neutral heating via SW electron precipitation tends to be more effective at altitudes below 160 km for integrated electron intensities above 0.01 ergs·cm−2·s−1 over the energy range of 3−450 eV. The results reported here highlight the necessity of incorporating SW electron precipitation as a heat source in the nightside Martian upper atmosphere under extreme circumstances such as during interplanetary coronal mass ejections.
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- 2021
8. Solar and Magnetic Control of Minor Ion Peaks in the Dayside Martian Ionosphere
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Xutong Wu, Yong Wei, D.-D. Niu, Juan Huang, Yongqiang Hao, Jianping Guo, and Jun Cui
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Martian ,Materials science ,010504 meteorology & atmospheric sciences ,Atmosphere of Mars ,Mass spectrometry ,01 natural sciences ,Physics::Geophysics ,Astrobiology ,Ion ,Magnetic field ,Geophysics ,Physics::Plasma Physics ,Space and Planetary Science ,Physics::Space Physics ,Astrophysics::Earth and Planetary Astrophysics ,Ionosphere ,0105 earth and related environmental sciences - Abstract
The Neutral Gas and Ion Mass Spectrometer of the Mars Atmosphere and Volatile Evolution provides a large data set to explore the ion composition and structure of the Martian ionosphere. Here the da...
- Published
- 2020
9. Energetic Electron Depletions in the Nightside Martian Upper Atmosphere Revisited
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Lihui Chai, S.-Q. Wu, H. Gu, D.-D. Niu, Xutong Wu, Yong Wei, Haoyu Lu, and Jun Cui
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Martian ,Atmosphere ,Geophysics ,010504 meteorology & atmospheric sciences ,Space and Planetary Science ,Feature (computer vision) ,Environmental science ,Electron ,01 natural sciences ,0105 earth and related environmental sciences ,Astrobiology - Abstract
Energetic electron depletions are a notable feature of the nightside Martian upper atmosphere. In this study, we investigate systematically the variations of the occurrence of depletions with both ...
- Published
- 2020
10. Dayside nitrogen and carbon escape on Titan: the role of exothermic chemistry
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F. He, Jun Cui, D.-D. Niu, Panayotis Lavvas, Yong Wei, H. Gu, XiaoShu Wu, J. H. Guo, Macau University of Science and Technology (MUST), National Astronomical Observatories [Beijing] (NAOC), Chinese Academy of Sciences [Beijing] (CAS), Groupe de spectrométrie moléculaire et atmosphérique (GSMA), Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS), Yunnan Astronomical Observatory, Institute of Geology and Geophysics [Beijing] (IGG), Space Science Institute [Macau] (SSI), School of Atmospheric Sciences [Zhuhai], and Sun Yat-Sen University [Guangzhou] (SYSU)
- Subjects
Exothermic reaction ,010504 meteorology & atmospheric sciences ,Atmospheric escape ,[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] ,Chemistry ,Astronomy and Astrophysics ,Astrophysics ,01 natural sciences ,Chemical reaction ,symbols.namesake ,13. Climate action ,Space and Planetary Science ,Chemical physics ,[SDU]Sciences of the Universe [physics] ,0103 physical sciences ,symbols ,Terrestrial planet ,[CHIM]Chemical Sciences ,Test particle ,Ionosphere ,Titan (rocket family) ,010303 astronomy & astrophysics ,Dissociative recombination ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences - Abstract
Context. Atmospheric escape has an appreciable impact on the long-term climate evolution on terrestrial planets. Exothermic chemistry serves as an important mechanism driving atmospheric escape and the role of such a mechanism is of great interest for Titan due to its extremely complicated atmospheric and ionospheric composition. Aims. This study is devoted to a detailed investigation of neutral N and C escape on the dayside of Titan, which is driven by exothermic neutral–neutral, ion–neutral, and dissociative recombination (DR) reactions. It was carried out based on the extensive measurements of Titan’s upper atmospheric structure by a number of instruments on board Cassini, along with an improved understanding of the chemical network involved. Methods. A total number of 14 C- and N-containing species are investigated based on 146 exothermic chemical reactions that release hot neutrals with nascent energies above their respective local escape energies. For each species and each chemical channel, the hot neutral production rate profile is calculated, which provides an estimate of the corresponding escape rate when combined with the appropriate escape probability profile obtained from a test particle Monte Carlo model. Results. Our calculations suggest a total N escape rate of 9.0 × 1023 s−1 and a total C escape rate of 4.2 × 1023 s−1, driven by exothermic chemistry and appropriate for the dayside of Titan. The former is primarily contributed by neutral-neutral reactions, whereas the latter is dominated by ion–neutral reactions; however, contributions from neutral–neutral and DR reactions to the latter cannot be ignored either. Our calculations further reveal that the bulk of N escape is driven by hot N(4S) production from the collisional quenching of N(2D) by ambient N2, while C escape is mainly driven by hot CH3 and CH4 production via a number of important ion–neutral and neutral–neutral reactions. Conclusions. Considered in the context of prior investigations of other known escape mechanisms, we suggest that exothermic chemistry is likely to contribute appreciably to non-thermal C escape on the dayside of Titan, although it plays an insignificant role in N escape.
- Published
- 2020
11. Non-thermal escape on Triton driven by atmospheric and ionospheric chemistry
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Xiaojian Wu, Yong Wei, Jun Cui, H. Gu, D.-D. Niu, and Fei He
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Physics ,Solar System ,010504 meteorology & atmospheric sciences ,Atmospheric escape ,Monte Carlo method ,Astronomy and Astrophysics ,Context (language use) ,Astrophysics ,01 natural sciences ,Molecular physics ,Space and Planetary Science ,0103 physical sciences ,Test particle ,Ionosphere ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences - Abstract
Context. Jeans escape is believed to dominate atmospheric escape for most outer Solar System bodies. However, non-thermal mechanisms, particularly atmospheric and ionospheric chemistry, are likely to contribute substantially to neutral escape on Triton. Aims. This study is devoted to evaluating the role of the chemically induced escape of H, H2, C, N, O, N2, and CO on Triton via a variety of processes. Here, we also aim to identify the dominant processes for these species. Methods. We used the background atmospheric and ionospheric structures from available model calculations. We constructed a test particle Monte Carlo model to determine the escape probability profiles of various species released from 35 channels. Species-dependent and energy-dependent cross sections were adopted in our calculations, along with a strongly forward-scattering angle distribution, all constrained by the available laboratory measurements. Results. The chemical escape rates on Triton are derived as 4.5 × 1024 s−1 for total H, 6.9 × 1022 s−1 for total C, 8.0 × 1024 s−1 for total N, and 1.4 × 1023 s−1 for total O. Conclusions. Based on a comparison with the respective Jeans escape rates, our calculations indicate that atmospheric and ionospheric chemistry make small but non-negligible contributions to both H and C escape on Triton, whereas its contributions to N and O escape are significant.
- Published
- 2021
12. In Situ Heating of the Nightside Martian Upper Atmosphere and Ionosphere: The Role of Solar Wind Electron Precipitation
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X. S. Wu, LongKang Dai, Y. ‐T. Cao, T. L. Zhang, Jun Cui, Zhaojin Rong, Yong Wei, Mingyu Wu, D.-D. Niu, and H. Gu
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Physics ,Martian ,Atmosphere ,In situ ,Solar wind ,Space and Planetary Science ,Electron precipitation ,Astronomy and Astrophysics ,Mars Exploration Program ,Ionosphere ,Atmospheric sciences - Abstract
In the absence of solar radiation, precipitating electrons from the solar wind (SW) are generally thought to be the dominant source of energy deposition in the nightside Martian upper atmosphere, creating a patchy ionosphere and possibly also affecting the nightside thermal budget of various neutral and ionized species. Previous model calculations have not taken into account in situ heating via SW electron impact. In the present study, we utilize extensive measurements made by several instruments on board the Mars Atmosphere and Volatile Evolution spacecraft, in order to perform data-driven computations of the nightside neutral, ion, and electron heating rates. Considering the large range of energetic electron intensity observed on the nightside of Mars, we divide the entire data set into two subsamples, either with or without energetic electron depletion, a notable feature of the nightside Martian ionosphere. Our calculations indicate that in situ nightside neutral heating is dominated by exothermic chemistry and Maxwell interaction with thermal ions for regions with depletion, and by direct SW impact for regions without. Collisional quenching of excited state species produced from a variety of channels, such as electron impact excitation, dissociation, and ionization, as well as dissociative recombination, makes a substantial contribution to neutral heating, except during depletion. For comparison, nightside ion heating is mainly driven by energetic ion production under all circumstances, which occurs mainly via ion-neutral reaction O+ + CO2 and CO2 + predissociation.
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- 2021
13. Numerical analysis of the damage detection in composite plates based on the electromechanical impedance method
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Y. Tie, D. D. Niu, and C. Li
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Materials science ,Admittance ,Mechanical Engineering ,Numerical analysis ,Composite number ,Condensed Matter Physics ,Piezoelectricity ,Finite element method ,Amplitude ,Mechanics of Materials ,Composite plate ,General Materials Science ,Composite material ,Electrical impedance - Abstract
The electromechanical impedance damage detection method for composite plates is presented in this paper using piezoelectric materials. The structural damage is characterised by the admittance signals obtained from the piezoelectric materials. The results obtained in this study show that the resonance frequency will change if the damage occurs. The maximum amplitude value of the conductance without damage is larger than that with damage. The amplitude value increases as the radius of the damage holes increases. Furthermore, according to the admittance signals of the two PZT patches, the PZT is more sensitive to the damage when it is closer to the damage. The root mean square deviation damage index based on the admittance signals can also effectively reflect the damage information in the composite plate.
- Published
- 2015
14. Monte Carlo Calculations of Helium Escape on Mars via Energy Transfer from Hot Oxygen Atoms
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D.-D. Niu, Kun Li, Jun Cui, H. Gu, and Zhaoguo He
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Physics ,Hydrogen ,Aeronomy ,Monte Carlo method ,chemistry.chemical_element ,Astronomy and Astrophysics ,Mars Exploration Program ,Oxygen ,Abundance of the chemical elements ,chemistry ,Space and Planetary Science ,Atomic physics ,Helium ,Exosphere - Published
- 2020
15. Neutral Heating Efficiency in the Dayside Martian Upper Atmosphere
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X. S. Wu, Z. P. Wu, Jun Cui, Y. T. Cao, Fei He, D. D. Niu, Jie Li, Yong Wei, and H. Gu
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Atmosphere ,Physics ,Martian ,Astrochemistry ,Space and Planetary Science ,Aeronomy ,Astronomy and Astrophysics ,Photoionization ,Mars Exploration Program ,Heating efficiency ,Astrobiology - Published
- 2020
16. Monte Carlo calculations of the atmospheric sputtering yields on Titan
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Jun Cui, Wei-Ling Tseng, D.-D. Niu, Anne Wellbrock, Xiaojun Xu, and H. Gu
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Physics ,010504 meteorology & atmospheric sciences ,Atmospheric escape ,Forward scatter ,Monte Carlo method ,Astronomy and Astrophysics ,Astrophysics ,01 natural sciences ,Power law ,Ion ,symbols.namesake ,Space and Planetary Science ,Sputtering ,0103 physical sciences ,symbols ,Atomic physics ,Titan (rocket family) ,010303 astronomy & astrophysics ,Excitation ,0105 earth and related environmental sciences - Abstract
Context. Sputtering serves as an important mechanism of atmospheric escape in the solar system. Aims. This study is devoted to atmospheric sputtering on Titan, with a special focus on how the N2 and CH4 sputtering yields respond to varying ion incidence energy and angle, and varying ion mass. Methods. A Monte Carlo model was constructed to track the energy degradation of incident ions and atmospheric recoils from which the sputtering yields were obtained. A large number of model runs were performed, taking into account three categories of incident ion with representative masses of 1, 16, and 28 Da, as well as two collision models both characterized by a strongly forward scattering angle distribution, but different in terms of the inclusion or exclusion of electronic excitation of ambient neutrals. Results. Our model calculations reveal substantial increases in both the N2 and CH4 sputtering yields with increasing ion incidence energy and angle, and increasing ion mass. The energy distribution of escaping molecules is described reasonably well by a power law, with an enhanced high energy tail for more energetic incident ions and less massive atmospheric recoils. The CH4-to-N2 sputtering yield ratio is found to range from 10 to 20%, increasing with increasing incidence angle and also increasing with decreasing incidence energy. An approximate treatment of ion impact chemistry is also included in our model, predicting N2 sputtering yields on Titan that are in broad agreement with previous results.
- Published
- 2019
17. A Test Particle Monte Carlo Investigation of the CH4 Torus around Saturn
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Chengyu Dong, Anne Wellbrock, D.-D. Niu, Xiaojun Xu, Fa-Yu Jiang, Jun Cui, L.-Y. Zhou, and H. Gu
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Physics ,010504 meteorology & atmospheric sciences ,Saturn (rocket family) ,Space and Planetary Science ,0103 physical sciences ,Monte Carlo method ,Astronomy and Astrophysics ,Torus ,Test particle ,010303 astronomy & astrophysics ,01 natural sciences ,0105 earth and related environmental sciences ,Computational physics - Published
- 2018
18. The characteristic analysis of the solar energy photovoltaic power generation system
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K Li, Yu Liu, B Liu, Yinhua Jin, and D D Niu
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Engineering ,Meteorology ,Power station ,business.industry ,Photovoltaic system ,Photovoltaic power station ,business ,Rooftop photovoltaic power station ,Maximum power point tracking ,Solar power ,Renewable energy ,Nominal power (photovoltaic) - Abstract
Solar energy is an inexhaustible, clean, renewable energy source. Photovoltaic cells are a key component in solar power generation, so thorough research on output characteristics is of far-reaching importance. In this paper, an illumination model and a photovoltaic power station output power model were established, and simulation analysis was conducted using Matlab and other software. The analysis evaluated the condition of solar energy resources in the Baicheng region in the western part of Jilin province, China. The characteristic curve of the power output from a photovoltaic power station was obtained by simulation calculation. It was shown that the monthly average output power of the photovoltaic power station is affected by seasonal changes; the output power is higher in summer and autumn, and lower in spring and winter.
- Published
- 2017
19. [Effects of hypoxia/reoxygenation on mitogen-activated protein kinase activity in cultured neonatal rabbit cardiac myocytes]
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W J, Yu, X H, Yao, X H, Liu, K, Chen, D D, Niu, J Y, Su, and C S, Tang
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Animals, Newborn ,Myocardium ,Ribosomal Protein S6 Kinases ,Calcium-Calmodulin-Dependent Protein Kinases ,Ischemic Preconditioning, Myocardial ,Animals ,Rabbits ,Cell Hypoxia ,Cells, Cultured - Abstract
Cardiomyocytes subjected to brief episode of hypoxia possess a resistance to serious damaging effect exerted by a subsequent long-time hypoxia on these cells, which is called hypoxic preconditioning (PC). The pathway of intracellular signal transduction during hypoxia PC has not yet been validated. On a model of hypoxia/reoxygenation (H/R) of cultured neonatal rabbit cardiomyocytes, the present study is taken to investigate the changes of mitogen-activated protein kinase (MAPK) and ribosomal S6 kinase (S6K) activity. It was found that intracellular total MAPK and nuclear MAPK, after a 15-min period of reoxygenation preceded by a single 60-min period of hypoxia, were increased by 95% and 230%, respectively. Intracellular S6K activity increased by 142% at 30 min of H/R vs the control group (P0.01). Phosphatase 1 (PPase 1) inhibitor (ocadaic acid, OA 1 mumol/L) augmented the increase of MAPK and S6K activity induced by H/R. However, tyrosine kinase (Tyr K) inhibitor (genistein), protein kinase C (PKC) inhibitor (H7) and preincubation of cardiomyocytes with PKC activator PMA all reduced MAPK activation by H/R. Protein kinase A (PKA) inhibitor (H89), Ca2+/Calmodulin-dependent protein kinase (PKM) inhibitor (W7) or PPase 2a inhibitor (OA 10 nmol/L) had no significant effect on MAPK and S6K activity. The above results suggested that activation of MAPK and S6K activity during hypoxia/reoxygenation there might require participation of PKC, Tyr K and PPase 1, while PKA, PKM and PPase 2a were not involved.
- Published
- 1998
20. Effect of endothelin, angiotensin II and ANP on proliferation of vascular smooth muscle cells and cardiomyocytes
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J M, Wu, T, Cheng, S D, Sun, D D, Niu, J X, Zhang, S H, Wang, J, Tang, and C S, Tang
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Angiotensin II ,Endothelins ,Myocardium ,Gene Expression ,Genes, fos ,Aorta, Thoracic ,DNA ,Muscle, Smooth, Vascular ,Rats ,Rats, Inbred SHR ,Animals ,Rabbits ,Rats, Wistar ,Atrial Natriuretic Factor ,Cell Division ,Cells, Cultured - Abstract
By means of cell culture, 3H-thymidine (3H-TdR) incorporation and c-fos oncogene dot plotting technique, it was found that endothelin (ET) and angiotensin (ANG II) could promote proliferation and DNA synthesis of cultured vascular smooth muscle cells (VSMCs) and myocardial cells, and stimulate expression of c-fos oncogene of VSMCs. However, atrial natriuretic peptide (ANP) antagonizes the above effects of ET and ANG II.
- Published
- 1993
21. Neutral Heating Efficiency in the Dayside Martian Upper Atmosphere.
- Author
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H. Gu, J. Cui, D.-D. Niu, Y.-T. Cao, X.-S. Wu, J. Li, Z.-P. Wu, F. He, and Y. Wei
- Published
- 2020
- Full Text
- View/download PDF
22. A Test Particle Monte Carlo Investigation of the CH4 Torus around Saturn.
- Author
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D.-D. Niu, J. Cui, H. Gu, C.-Y. Dong, L.-Y. Zhou, A. Wellbrock, F.-Y. Jiang, and X.-J. Xu
- Published
- 2019
- Full Text
- View/download PDF
23. The characteristic analysis of the solar energy photovoltaic power generation system.
- Author
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B Liu, K Li, D D Niu, Y A Jin, and Y Liu
- Published
- 2017
- Full Text
- View/download PDF
24. [Renal leukocyte chemokine type 2 amyloidosis: a clinicopathological analysis of fifteen cases].
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Wang XY, Han WX, Chen SY, Niu D, Wang XY, and Wang C
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- Humans, Male, Female, Middle Aged, Proteinuria, Biopsy, Intercellular Signaling Peptides and Proteins metabolism, Glomerulonephritis, Membranous pathology, Glomerulonephritis, Membranous metabolism, Glomerulonephritis, IGA pathology, Glomerulonephritis, IGA metabolism, Aged, Hematuria etiology, Renal Insufficiency metabolism, Amyloidosis metabolism, Amyloidosis pathology, Amyloidosis diagnosis, Nephrotic Syndrome metabolism, Nephrotic Syndrome pathology, Kidney pathology, Kidney Diseases pathology, Kidney Diseases metabolism
- Abstract
Objective: To investigate the clinicopathological features of renal leukocyte chemokine type 2 amyloidosis (ALECT2). Methods: The prevalence, clinical characteristics, renal histopathological features, and renal outcome of 15 patients with ALECT2 by kidney biopsy were collected in the Department of Kidney Pathology, Shanxi Medical University Second Hospital, Taiyuan, China from January 1993 to December 2023. Immunohistochemistry and mass spectrometry for amyloid proteins were carried out. Results: Fifteen patients with ALECT2 were included in the study, representing 12.93% (15/116) of the renal biopsy-proven amyloidosis cases. There were 5 males and 10 females. The median age at diagnosis was 61 years. All patients had various degrees of proteinuria; 7 patients had nephrotic syndrome; 3 patients had renal insufficiency; 7 patients had microscopic hematuria. Renal biopsy showed that strongly orangophilic amyloid proteins distributed mainly in the renal cortical interstitium, vascular walls, the glomerular mesangium and/or glomerular basement membrane. Eight cases were diagnosed with ALECT2 alone and 7 cases combined with other renal diseases, including 4 cases with membranous nephropathy, 2 cases with IgA nephropathy, and 1 case with subacute tubular interstitial nephropathy. ALECT2 patients with concurrent renal disease showed a higher proteinuria level than those without (3.48 g/24 h versus 4.58 g/24 h). All patients were corroborated by immunohistochemistry to exhibit the specific location of LECT2 in the amyloid fibrils. Mass spectrometry analysis revealed LECT2 polypeptide in 9 patients. Except two patients with worsening renal function, the others showed stable renal function during the mean follow-up period of 12.5 months. Conclusions: ALECT2 is the second common type of renal amyloidosis in our center. The majority of ALECT2 patients show concurrent renal diseases, with a high rate of membranous nephropathy. Amyloid deposits distribute mainly in the cortical interstitium of the kidney, the glomerular mesangium and vascular walls. Mass spectrometry is the most sensitive and specific method for detecting LECT2 amyloidosis.
- Published
- 2024
- Full Text
- View/download PDF
25. Plant functional traits shape growth rate for xerophytic shrubs.
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Zhang C, Niu D, Zhang L, Li X, and Fu H
- Subjects
- Biomass, Phenotype, Plant Leaves, Plants
- Abstract
Trade-offs exist for xerophytic shrubs between functional traits, involving in water loss and assimilate accumulation, can contribute to its survival and growth rate regulation in arid environments. However, growth analysis based on plant functional traits has been focused on the study of herbs and woody species. It is still unclear how the functional traits of xerophytic shrubs regulate their growth rate. In this study, we selectedeight xerophytic shrubs as samples to analyze the regulation process of the functional traits of shrubs on growth rate. Plants were cultivated for three years, and three harvests (every one year) were carried out. Factors explaining between-species differences in relative growth rate (RGR) varied, depending on whether different ages were considered. The results showed that RGR was positively correlated with net assimilation rate, but there was a significant negative correlation with leaf area ration (LAR), specific leaf area (SLA), and leaf biomass ratio in the age 1. However, in the age 2, RGR showed a significant positive correlation with the morphological traits (i.e., leaf area ration and specific leaf area), but not with physiological traits (i.e., net assimilation rate) and leaf biomass allocation. Our results suggested that the fluctuation of environmental factors affects the regulation path of the plant functional traits on RGR of xerophytic shrubs. However, the analysis of causality model showed that no matter in which age, net assimilation rate and leaf area ration principally drive the variation in RGR among xerophytic shrubs., (© 2021 German Society for Plant Sciences, Royal Botanical Society of the Netherlands.)
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- 2022
- Full Text
- View/download PDF
26. [The reference intervals of thyroid functional indicators in pregnant population in Xi'an].
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Meng GL, Wang Q, Kang R, Niu D, Xing N, and Xie Y
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- Cross-Sectional Studies, Female, Humans, Pregnancy, Reference Values, Thyroid Function Tests, Thyrotropin, Triiodothyronine, Thyroid Gland, Thyroxine
- Abstract
To establish reference intervals for thyroid functional indicators in early (T1), mid-term (T2), and late stage (T3) pregnancy in a population of women in Northwestern China. A cross-sectional study was conducted on 620 pregnant women. Subjects were recruited through a questionnaire where apparently healthy women were selected. Serum thyroid stimulating hormone (TSH3), total triiodothyronine (TT3), total thyroid hormone (TT4), free triiodothyronine (FT3), and free thyroid hormone (FT4) were detected using the Beckman Unicel DXI 800 automatic chemiluminescence analyzer (the third-generation TSH detection reagent for TSH3),and the reference intervals of different gestation periods were established. The results showed that the reference intervals of TSH3 in T1, T2, and T3 were 0.05-4.59, 0.61-6.01, and 0.63-4.78 mIU/L, respectively; TT3 were 1.62-2.97 nmol/L, 1.59-2.95 nmol/L, and 1.45-2.70 nmol/L, respectively; TT4 were 95.49-185.00 nmol/L, 92.70-181.54 nmol/L, and 77.93-155.09 nmol/L, respectively; FT3 were 3.18-5.22 pmol/L, 2.78-4.67 pmol/L, and 2.51-4.18 pmol/L, respectively; and FT4 were 7.72-12.97 pmol/L, 6.90-1.09 pmol/L, and 5.63-9.85 pmol/L, respectively. All thyroid function indexes had statistically significant differences between the three stages of pregnancy (TSH: H =30.879, P <0.01;FT3: H =153.827, P <0.01;FT4: H =229.967, P <0.01;TT3: H =36.484, P <0.01;TT4: H =58.531, P <0.01). 20 independent samples were collected to verify the reference intervals of TSH, FT3, FT4, TT3 and TT4 for three trimesters of pregnancy, and all of them passed.
- Published
- 2021
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- View/download PDF
27. [Radial artery thrombosis in optical coherence tomography guided transradial coronary angiography and percutaneous coronary intervention in acute coronary syndrome patients and its risk factors analysis].
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Liu ZJ, Niu D, Li ZX, and Guo JC
- Abstract
Objective: To observe the radial artery thrombosis (RAT) during transradial coronary angiography (CAG) and/or percutaneous coronary intervention (PCI) by optical coherence tomography (OCT), and to investigate the risk factors of RAT during the CAG and/or PCI. Methods: In this retrospective study, we consecutively reviewed the radial artery OCT examination results of the patients who underwent OCT guided transradial CAG and/or PCI for acute coronary syndrome in heart center of Beijing Luhe hospital, Capital Medical University from October 2017 to July 2018. The incidence of RAT was observed. The patients were divided into the RAT group and non-RAT group, clinical data were collected and compared. Moreover, the types and distributions of thrombus in radial artery as well as the acute radial artery injuries under OCT were observed. Univariate analysis followed by multivariate analysis were performed to identify potential risk factors. The radial artery patency and ischemic symptoms of the involved limb were followed up at the 24-hour and the 1-month after procedure. Results: A total of 107 patients were included, the age was (58.1±12.5), and 78.5% were male ( n =84). The incidence of RAT was 26.2% ( n =28, 95% CI 17.9%-34.5%), and the main type of thrombus was white thrombus ( n =15, 53.6%). The commonest position of RAT was the proximal portion of radial artery ( n =17, 60.7%). The median thrombus volume was 0.05(0.03, 0.38) mm
3 , and the median thrombus score was 6.5 (3.3, 13.8). In univariate analysis, the frequency of acute radial artery injury and use of bivalirudin were significantly higher and the procedure time was significantly longer in RAT group than those in non-RAT group (all P <0.05). Multivariate regression analysis showed that the radial artery acute injury ( OR= 5.82, 95% CI: 2.09-16.20, P =0.001) and the procedure time ( OR= 1.04, 95% CI: 1.01-1.06, P =0.006) were independent risk factors of RAT. Rate of radial artery occlusion at 24 hours follow-up was similar between RAT and non-RAT group (7.14%(2/28), vs. 10.13%(8/79), P =1.000). None of the patients complicated severe ischemic symptom of the operative limb. Conclusions: RAT is a high frequency access complication during transradial coronary intervention. This phenomenon can be accurately observed by OCT. Acute radial artery injury and prolonged procedure time are risk factors of RAT during transradial coronary intervention.- Published
- 2021
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28. Effect of phosphorus efficiency on elemental stoichiometry of two shrubs.
- Author
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Hu X, Zhang L, Zhang D, Niu D, and Fu H
- Subjects
- Biomass, Rhizosphere, Soil chemistry, Magnoliopsida metabolism, Phosphorus metabolism, Zygophyllum growth & development, Zygophyllum metabolism
- Abstract
Phosphorus (P) is an important nutrient that can restrict plant growth. However, the influence of P deficiency on elemental homeostasis and application of the growth rate hypothesis in higher plants remain to be assessed. Two shrubs, Zygophyllum xanthoxylum and Nitraria tangutorum, were used as experiment material and subjected to five P addition treatments: 0, 17.5, 35.0, 52.5 and 70.0 mg P·kg
-1 soil. The biomass and relative growth rate of Z. xanthoxylum did not change with altered P supply. There was no significant difference in P concentration among the treatments for Z. xanthoxylum, but N. tangutorum showed an upward trend. The P stoichiometric homeostasis of Z. xanthoxylum was higher than that of N. tangutorum. For Z. xanthoxylum, available P in the rhizosphere improved significantly under extreme P deficiency conditions, and P concentrations in all treatments were lower than in N. tangutorum, showing that Z. xanthoxylum had stronger P absorption and P utilization capacity. No relationships between growth rate and C:N:P ratios were found in Z. xanthoxylum. The strong P efficiency, and high and stable dry matter accumulation, are likely contributors in maintaining stoichiometric homeostasis. In addition, the relatively high biomass accumulation and high P utilization efficiency for Z. xanthoxylum does not support the growth rate hypothesis for this species., (© 2020 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.)- Published
- 2020
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29. Knockdown of long non-coding RNA VIM-AS1 inhibits glioma cell proliferation and migration, and increases the cell apoptosis via modulation of WEE1 targeted by miR-105-5p.
- Author
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Suo ST, Gong P, Peng XJ, Niu D, and Guo YT
- Subjects
- Animals, Apoptosis, Brain Neoplasms pathology, Cell Cycle Proteins metabolism, Cell Movement, Cell Proliferation, Glioma pathology, Humans, Mice, Mice, Inbred BALB C, Mice, Nude, MicroRNAs metabolism, Neoplasms, Experimental metabolism, Neoplasms, Experimental pathology, Protein-Tyrosine Kinases metabolism, RNA, Long Noncoding metabolism, Tumor Cells, Cultured, Brain Neoplasms metabolism, Cell Cycle Proteins genetics, Glioma metabolism, MicroRNAs genetics, Protein-Tyrosine Kinases genetics, RNA, Long Noncoding genetics
- Abstract
Objective: Glioma including glioblastoma is the main type of primary brain tumors worldwide. LncRNAs have participated in glioma formation. This study aims to investigate the underlying mechanism for VIM-AS1/miR-105-5p/WEE1 signaling in glioma., Patients and Methods: The clinical tumors and adjacent tissues were collected from 24 patients with glioma in the Shang Luo Central Hospital. Then, the clinical samples were subjected to hematoxylin-eosin staining (H&E). VIM-AS1, miR-105-5p, and WEE1 levels were measured using real-time PCR. The protein levels of WEE1, Cyclin A1, PCNA, N-cadherin, Vimentin, and Bcl-2, E-cadherin, and Bax were analyzed using Western blot. The overall survival of glioma patients was evaluated using the Kaplan-Meier analysis. The interaction between VIM-AS1 and miR-105-5p was determined using RIP assay and Dual-Luciferase reporter assay, and the binding between miR-105-5p and WEE1 was also detected by Dual-Luciferase reporter assay. Cell proliferation, colony formation, cell cycle, apoptosis, and migration were confirmed using CCK-8, colony formation assay, flow cytometry, and transwell assay, respectively., Results: VIM-AS1 was elevated in cancer tissues, and high level of VIM-AS1 was positively correlated with poor overall survival. Then, VIM-AS1 could bind to and downregulate miR-105-5p. Furthermore, the knockdown of VIM-AS1 significantly suppressed tumor growth in vivo. The knockdown of VIM-AS1/overexpression of miR-105-5p inhibited glioma cell growth, colony formation, and migration, and enhanced the cell apoptosis by inhibiting expression of Cyclin A1, PCNA, Vimentin, N-cadherin, and Bcl-2, and by increasing the expression of Bax and E-cadherin. Interestingly, the overexpression of VIM-AS1 reversed the tumor-suppressing role of miR-105-5p in glioma cells. Besides, the expression of WEE1 was synergistically regulated by VIM-AS1 and miR-105-5p. Consequently, VIM-AS1 promoted glioma progression via upregulating WEE1 or downregulating miR-105-5p., Conclusions: VIM-AS1/miR-105-5p/WEE1 signaling may be a promising target for glioma treatment.
- Published
- 2020
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30. Sensitivity of resonance properties of all-dielectric multilayers driven by statistical fluctuations.
- Author
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Lereu AL, Lemarchand F, Zerrad M, Niu D, Aubry V, Passian A, and Amra C
- Abstract
In photonics and emerging fields of quantum and topological materials, increasing demands are placed upon the state and control of electromagnetic fields. Dielectric multilayer materials may be designed and optimized to possess extremely sharp spectral and angular photonic resonances allowing for the creation of fields orders of magnitude larger than the exciting field. With enhancements of 10
4 and higher, the extreme nature of these resonances places high constraints on the statistical properties of the physical and optical characteristics of the materials. To what extent the spectral and angular shifts occur as a result of fluctuations in the refractive indices and morphologies of the involved low-loss subdomains have not been considered previously. Here, we present how parameter variations such as those caused by fluctuations in deposition rate, yielding bias, random and compensated errors, may affect the resonance properties of low-loss all-dielectric stacks.- Published
- 2019
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31. Responses of leaf C:N:P stoichiometry to water supply in the desert shrub Zygophyllum xanthoxylum.
- Author
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Niu D, Zhang C, Ma P, Fu H, and Elser JJ
- Subjects
- Plant Leaves anatomy & histology, Plant Leaves growth & development, Water, Carbon metabolism, Desert Climate, Nitrogen metabolism, Phosphorus metabolism, Plant Leaves metabolism, Water Supply, Zygophyllum metabolism
- Abstract
Based on the elemental composition of major biochemical molecules associated with different biological functions, the 'growth rate hypothesis' proposed that organisms with a higher growth rate would be coupled to lower C:N, especially lower C:P and N:P ratios. However, the applicability of the growth rate hypothesis for plants is unclear, especially for shrubs growing under different water supply. We performed an experiment with eight soil moisture levels (soil water content: 4%, 6%, 8%, 13%, 18%, 23%, 26% and 28%) to evaluate the effects of water availability on leaf C:N:P stoichiometry in the shrub Zygophyllum xanthoxylum. We found that leaves grew slowly and favored accumulation of P over C and N under both high and low water supply. Thus, leaf C:P and N:P ratios were unimodally related to soil water content, in parallel with individual leaf area and mass. As a result, there were significant positive correlations between leaf C:P and N:P with leaf growth (u). Our result that slower-growing leaves had lower C:P and N:P ratios does not support the growth rate hypothesis, which predicted a negative association of N:P ratio with growth rate, but it is consistent with recent theoretical derivations of growth-stoichiometry relations in plants, where N:P ratio is predicted to increase with increasing growth for very low growth rates, suggesting leaf growth limitation by C and N rather than P for drought and water saturation., (© 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.)
- Published
- 2019
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32. Exposure to electromagnetic fields aboard high-speed electric multiple unit trains.
- Author
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Niu D, Zhu F, Qiu R, and Niu Q
- Subjects
- China, Environmental Exposure, Humans, Magnetic Fields, Maximum Allowable Concentration, Electric Power Supplies, Electromagnetic Fields, Railroads
- Abstract
High-speed electric multiple unit (EMU) trains generate high-frequency electric fields, low-frequency magnetic fields, and high-frequency wideband electromagnetic emissions when running. Potential human health concerns arise because the electromagnetic disturbances are transmitted mainly into the car body from windows, and from there to passengers and train staff. The transmission amount and amplitude distribution characteristics that dominate electromagnetic field emission need to be studied, and the exposure level of electromagnetic field emission to humans should be measured. We conducted a series of tests of the on board electromagnetic field distribution on several high-speed railway lines. While results showed that exposure was within permitted levels, the possibility of long-term health effects should be investigated.
- Published
- 2016
33. Wettability modified nanoporous ceramic membrane for simultaneous residual heat and condensate recovery.
- Author
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Hu HW, Tang GH, and Niu D
- Abstract
Recovery of both latent heat and condensate from boiler flue gas is significant for improving boiler efficiency and water conservation. The condensation experiments are carried out to investigate the simultaneous heat and mass transfer across the nanoporous ceramic membranes (NPCMs) which are treated to be hydrophilic and hydrophobic surfaces using the semicontinuous supercritical reactions. The effects of typical parameters including coolant flow rate, vapor/nitrogen gas mixture temperature, water vapor volume fraction and transmembrane pressure on heat and mass transfer performance are studied. The experimental results show that the hydrophilic NPCM exhibits higher performances of condensation heat transfer and condensate recovery. However, the hydrophobic modification results in remarkable degradation of heat and condensate recovery from the mixture. Molecular dynamics simulations are conducted to establish a hydrophilic/hydrophobic nanopore/water liquid system, and the infiltration characteristics of the single hydrophilic/hydrophobic nanopore is revealed.
- Published
- 2016
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34. The effect of surface wettability on water vapor condensation in nanoscale.
- Author
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Niu D and Tang GH
- Abstract
The effect of surface wettability on condensation heat transfer in a nanochannel is studied with the molecular dynamics simulations. Different from the conventional size, the results show that the filmwise mode leads to more efficient heat transfer than the dropwise mode, which is attributed to a lower interfacial thermal resistance between the hydrophilic surface and the condensed water compared with the hydrophobic case. The observed temperature jump at the solid-liquid surface confirms that the hydrophilic properties of the solid surface can suppress the interfacial thermal resistance and improve the condensation heat transfer performance effectively.
- Published
- 2016
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35. Transcriptome comparison between inactivated and activated ovaries of the honey bee Apis mellifera L.
- Author
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Niu D, Zheng H, Corona M, Lu Y, Chen X, Cao L, Sohr A, and Hu F
- Subjects
- Animals, Bees physiology, Female, Ovary physiology, Real-Time Polymerase Chain Reaction, Reproducibility of Results, Sequence Analysis, RNA, Bees genetics, Gene Expression Regulation, Transcriptome
- Abstract
Ovarian activity not only influences fertility, but is also involved with the regulation of division of labour between reproductive and behavioural castes of female honey bees. In order to identify candidate genes associated with ovarian activity, we compared the gene expression patterns between inactivated and activated ovaries of queens and workers by means of high-throughput RNA-sequencing technology. A total of 1615 differentially expressed genes (DEGs) was detected between ovaries of virgin and mated queens, and more than 5300 DEGs were detected between inactivated and activated worker ovaries. Intersection analysis of DEGs amongst five libraries revealed that a similar set of genes (824) participated in the ovary activation of both queens and workers. A large number of these DEGs were predominantly related to cellular, cell and cell part, binding, biological regulation and metabolic processes. In addition, over 1000 DEGs were linked to more than 230 components of Kyoto Encyclopedia of Genes and Genomes pathways, including 25 signalling pathways. The reliability of the RNA-sequencing results was confirmed by means of quantitative real-time PCR. Our results provide new insights into the molecular mechanisms involved in ovary activation and reproductive division of labour., (© 2014 The Royal Entomological Society.)
- Published
- 2014
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36. Mapping the p53 transcriptome universe using p53 natural polymorphs.
- Author
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Wang B, Niu D, Lam TH, Xiao Z, and Ren EC
- Subjects
- Antibiotics, Antineoplastic pharmacology, Cell Proliferation drug effects, Chromatin Immunoprecipitation, DNA metabolism, Doxorubicin pharmacology, Gene Regulatory Networks, HCT116 Cells, Humans, Polymorphism, Single Nucleotide, Protein Binding, Protein Structure, Tertiary, RNA Interference, RNA, Messenger metabolism, RNA, Small Interfering metabolism, STAT4 Transcription Factor chemistry, STAT4 Transcription Factor genetics, STAT4 Transcription Factor metabolism, Sequence Analysis, DNA, Transcriptome drug effects, Tumor Suppressor Protein p53 antagonists & inhibitors, Tumor Suppressor Protein p53 genetics, Tumor Suppressor Protein p53 metabolism
- Abstract
The tumor suppressor p53 has defined roles in varied cellular processes including apoptosis and DNA repair. While conventional genomic approaches have suggested a large number of p53 targets, there is a need for a systematic approach to validate these putative genes. We developed a method to identify and validate p53's transcriptional behavior by utilizing 16 non-synonymous p53 single-nucleotide polymorphism (SNP) variants. Five SNPs located within the DNA-binding domain of p53 were found to be functionally null, whereas the other 11 SNPs were p53WT-like in behavior. By integrating p53 ChIP-seq analysis with transcriptome data from the p53 SNP variants, 592 genes were identified as novel p53 targets. Many of these genes mapped to previously less well-characterized aspects of p53 function, such as cell signalling, metabolism, central nervous system, and immune system. These data provide pivotal insights into the involvement of p53 in diverse pathways of normal physiological processes and open new avenues for investigation of p53 function.
- Published
- 2014
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37. Expression pattern of adipocyte fatty acid-binding protein gene in different tissues and its regulation of genes related to adipocyte differentiation in duck.
- Author
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He J, Tian Y, Li JJ, Shen JD, Tao ZR, Fu Y, Niu D, and Lu LZ
- Subjects
- Animals, Cell Differentiation, Cell Survival, Fatty Acid-Binding Proteins genetics, Female, Gene Expression, Male, Oleic Acid, RNA, Messenger genetics, RNA, Messenger metabolism, Reverse Transcriptase Polymerase Chain Reaction, Adipocytes cytology, Ducks physiology, Fatty Acid-Binding Proteins metabolism
- Abstract
Abundance of duck adipocyte fatty acid-binding protein (A-FABP) mRNA was detected in this study by quantitative real-time PCR. The results showed that duck A-FABP gene was expressed in muscular tissues and many organs, except pancreas, lung, and kidney, and highly expressed in adipose tissues, especially in sebum. The expression of A-FABP and adipocyte differentiation-related genes was upregulated by oleic acid, and the A-FABP knockdown suppressed the oleic acid-stimulated expression of these genes in the cultured duck adipocytes, indicating A-FABP might play an important role in duck adipocyte differentiation.
- Published
- 2012
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38. Effects of perilla extract on productive performance, serum values and hepatic expression of lipid-related genes in Shaoxing ducks.
- Author
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Liu WM, Zhang J, Lu LZ, Shi FX, Niu D, Wang DL, Yu B, Tao ZR, Shen JD, Wang DQ, and Tian Y
- Subjects
- Acyl-CoA Oxidase metabolism, Animal Feed, Animals, Cholesterol blood, Cholesterol, HDL blood, Diet veterinary, Ducks metabolism, Fatty Acid-Binding Proteins genetics, Fatty Acid-Binding Proteins metabolism, Female, Lipoproteins blood, Liver physiology, PPAR alpha genetics, PPAR alpha metabolism, Polymerase Chain Reaction, RNA, Messenger analysis, RNA, Messenger genetics, Reproduction drug effects, Triglycerides blood, Ducks genetics, Gene Expression Regulation drug effects, Lipid Metabolism, Liver drug effects, Perilla chemistry, Plant Extracts pharmacology
- Abstract
1. The aim of this study was to identify the effect of perilla extract, a source of polyunsaturated fatty acids, on lipid metabolism and expression of lipid-related genes in livers of Shaoxing ducks. 2. Two hundred and forty 28-week-old laying ducks received a commercial diet with perilla extract added at 0 (control) or 200 mg/kg of feed. 3. Ducks fed on a diet with perilla extract had increased laying rates compared with control ducks. 4. Serum concentrations of triglycerides were reduced by perilla extract, while high-density lipoprotein cholesterol and total serum cholesterol increased. 5. The expression of genes involved in hepatic lipogenesis, sterol regulatory element-binding protein-1, acetyl CoA carboxylase, stearoyl CoA desaturase, fatty acid synthase, apolipoprotein B, and apolipoprotein very low density lipoprotein, were decreased in the perilla group. 6. The mRNA expression of peroxisome proliferators-activated receptor alpha and acyl-coenzyme A oxidase was enhanced following treatment with perilla extract, and a similar tendency was observed in the expression of liver fatty acid-binding protein. 7. The results show that a diet with 200 mg/kg perilla extract regulated fat metabolism of Shaoxing ducks by improving egg laying, altering serum lipid profiles, stimulating lipid catabolic gene expression and inhibiting lipogenic gene expression in the liver.
- Published
- 2011
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39. Giant oesophageal liposarcoma mimicking spindle cell liposarcoma and containing eosinophilic cells with rhabdomyoblastic differentiation.
- Author
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Nakazawa T, Kondo T, Niu D, Ma D, Mochizuki K, Kawasaki T, Kawaguchi Y, Kono K, Fujii H, and Katoh R
- Subjects
- Aged, 80 and over, Cell Differentiation, Diagnosis, Differential, Eosinophils pathology, Humans, Male, Esophageal Neoplasms pathology, Liposarcoma pathology
- Published
- 2010
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40. Mesenchymal stroma cells improve hyperglycemia and insulin deficiency in the diabetic porcine pancreatic microenvironment.
- Author
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Chang C, Niu D, Zhou H, Zhang Y, Li F, and Gong F
- Subjects
- Animals, Blood Glucose analysis, Cell Differentiation, Diabetes Mellitus, Experimental blood, Diabetes Mellitus, Experimental pathology, Diabetes Mellitus, Experimental physiopathology, Female, Green Fluorescent Proteins genetics, Immunophenotyping, Insulin immunology, Islets of Langerhans pathology, Male, Mesenchymal Stem Cells metabolism, Mesenchymal Stem Cells pathology, Pancreas surgery, Recovery of Function, Stromal Cells metabolism, Stromal Cells pathology, Swine, Swine, Miniature, Transfection, Diabetes Mellitus, Experimental therapy, Hyperglycemia therapy, Insulin deficiency, Mesenchymal Stem Cell Transplantation, Pancreas metabolism
- Abstract
Background: Stem cell differentiation is controlled by extracellular cues from the environment and by intrinsic genetic programs within the stem cell. The present study aimed to explore whether mesenchymal stromal cells (MSC) could improve hyperglycemia and insulin production in the diabetic microenvironment., Methods: We transplanted male porcine bone marrow-derived EGFP-expressing MSC directly into female diabetic porcine pancreas by multi-point injection. Enzyme-linked immunosorbent assay (ELISA) and fluorescent immunohistochemistry were used to analyze recipients' sera and pancreas tissues for assessment of the therapeutic effect., Results: Blood glucose levels decreased gradually in MSC-treated recipients from 15 days after the transplantation compared with untreated diabetic controls (15.94+/-0.31 mmol/L versus 16.66+/-0.11 mmol/L; P=0.01). Blood insulin increased and glucagons decreased notably in recipients from 2 weeks post-transplantation compared with untreated diabetic controls (0.049+/-0.004 microg/L versus 0.037+/-0.02 microg/L and 392.9+/-20.3 ng/L versus 433.1+/-27.6 ng/L). Hematoxylin and eosin (HE)-stained sections demonstrated that the number of islets from each section was markedly increased in recipients compared with that of diabetic controls (10.9+/-2.2 versus 4.6+/-1.4; P<0.05) and similar to that of normal controls (10.9+/-2.2 versus 12.6+/-2.6; P>0.05). The newly formed islets were smaller than normal islets (47.2+/-19.6 microm versus 119.6+/-27.7 microm; P<0.05). Analysis of pancreatic sections for EGFP in recipients indicated that the transplanted MSC survived within the pancreas. Insulin immunoreactivity of pancreatic islets showed that the newly formed islets expressed insulin., Discussion: MSC could improve diabetes upon pancreatic microenvironment without obvious immune rejections. This has theoretical and clinical applications.
- Published
- 2008
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41. Mesenchymal stem cells contribute to insulin-producing cells upon microenvironmental manipulation in vitro.
- Author
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Chang C, Niu D, Zhou H, Li F, and Gong F
- Subjects
- Animals, C-Peptide analysis, Femur physiology, Humans, Insulin Secretion, Islets of Langerhans cytology, Models, Animal, Pancreas cytology, Rabbits, Insulin metabolism, Mesenchymal Stem Cell Transplantation
- Abstract
Background: Extracellular microenvironment and intrinsic genetic programs determine the fate of stem cells. We observed whether mesenchymal stem cells (MSCs) contributed to insulin-producing cells in a manipulated microenvironment., Methods: We delivered pancreatic pieces into Niobium-Coated Dynamatrix to construct a simulated pancreatic microenvironment, upon which soluble cytokine exchange and direct cell-cell contact between MSCs and pancreatic cells could occur. Bone marrow-derived MSCs were cultured upon the microenvironment. Differentiated isletlike cells were observed under an inverted microscope. Insulin in supernates was measurement by enzyme-linked immunosorbent assay. Insulin and c-peptide expression were verified by fluorescent immunocytochemistry and fluorescence in situ hybridization. Apoptosis of isletlike masses in high-glucose DMEM was detected by FACS., Results: After 3 to 4 weeks in culture, typical isletlike masses were observed. Insulin secreted by differentiated cells (414.47+/-30.30 mIU/L) was much greater than that of undifferentiated cells (4.89+/-1.01 mIU/L; P<.05). Insulin and c-peptide expression were positive both in protein and mRNA levels. The transdifferentiated isletlike mass did not undergo apoptosis after another 3 weeks of culture in high-glucose DMEM., Conclusion: This simulated injury microenvironment without induction guided MSCs to functional isletlike cells hopefully to replace beta cells.
- Published
- 2007
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42. [cDNA cloning and mRNA expression pattern in follicles of the mature inhibin alpha subunit from Xianju chicken].
- Author
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Fu Y, Niu D, Ruan H, Yu XP, Chen G, He GQ, and Yang PX
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Cloning, Molecular, Female, Glycosylation, Inhibins chemistry, Molecular Sequence Data, Reverse Transcriptase Polymerase Chain Reaction, Chickens genetics, Inhibins genetics, Ovarian Follicle metabolism, RNA, Messenger analysis
- Abstract
The mature region of Xianju chicken inhibin alpha-subunit was amplified from the total RNA of follicle granulosa cells by RT-PCR using the primer pair designed according to the reported cDNA sequence of chicken inhibin alpha-subunit, and this fragment of alpha-subunit was cloned and sequenced subsequently. The results revealed that the mature alpha-subunit of Xianju chicken was a fragment of 113 amino acids containing one glycosylation site and seven cysteine residues. It was approximately 98% and 61.4%-68.7% identical in nucleotide sequence, 97.3% and 64.6%-69% similar in deduced amino acid sequence, respectively, in the mature region to the chicken and mammalian inhibin alpha-subunit cDNA clone. As for the mature chicken inhibin alpha-subunit, the number of potential glycosylation site and cysteine residues was the same, and their corresponding positions in the amino acid sequences were almost identical as compared to chicken and mammalian inhibin alpha-subunit, which indicated that the inhibin alpha-subunit was highly conserved among different species, implying an important role of inhibin alpha-subunit in various animals. The quantitative analysis of competitive RT-PCR for inhibin alpha-subunit revealed that the expression of alpha-subunit decreased with further follicle maturity from SYF to F1 follicle. The highest level of inhibin alpha-subunit mRNA was found in the SYF and F6-8 follicles, which indicated that inhibin alpha-subunit played an important role during the course of follicular recruitment, selection and dominance.
- Published
- 2001
43. [Studies of the origin of Chinese domestic fowls].
- Author
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Fu Y, Niu D, Luo J, Ruan H, He GQ, and Zhang YP
- Subjects
- Animals, Base Sequence, Chickens classification, DNA, Mitochondrial chemistry, Molecular Sequence Data, Phylogeny, Chickens genetics
- Abstract
A total of 539 bases fragment of mitochondrial DNA D-loop region of six domestic chicken breeds (30 individuals) were sequenced and compared to that of red junglefowl, grey junglefowl, green junglefowl and Lafayette's junglefowl issued in GenBank, and the phylogenetic trees for the chickens constructed based on the D-loop sequences. The results indicated that the four species of genus Gallus had great differences between each other, the G. g. domesticus was the next of kin to red junglefowl in Thailand and its adjacent regions, and near of kin to red junglefowl in Indonesian, Lafayette's junglefowl, grey junglefowl and green junglefowl one by one in proper order, suggesting that the red junglefowl in Thailand and its neighbour areas sufficed as the matriarchic ancestor of Chinese domestic fowls. It was also discovered that the two subspecies of Thailand i.e. G. g. gallus and G. g. spadiceus should belong to one subspecies because of their far lower differentiation compared to that among the domestic breeds.
- Published
- 2001
44. The first stereoselective total synthesis of quinine.
- Author
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Stork G, Niu D, Fujimoto RA, Koft ER, Balkovec JM, Tata JR, and Dake GR
- Subjects
- Stereoisomerism, Antimalarials chemical synthesis, Quinine chemical synthesis
- Abstract
The first entirely stereoselective total synthesis of (-)-quinine is reported.
- Published
- 2001
- Full Text
- View/download PDF
45. [Studies of genetic diversity of Zhejiang native chicken breeds].
- Author
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Fu Y, Niu D, Ruan H, Luo J, Chen G, Yu XP, and Zhang YP
- Subjects
- Animals, Base Sequence, Breeding, DNA, Mitochondrial chemistry, Molecular Sequence Data, Chickens genetics, Genetic Variation
- Abstract
A total of 539 bases of mitochondrial DNA D-loop region of five native chicken breeds of Zhejiang province and the white leghorn chicken (as the control) were sequenced by DNA sequencing technique, and the phylogenetic trees of the chicken breeds were constructed. The results showed that 24 variation sites i.e. 4.45% sequence divergence were detected among the 30 DNA sequences, and the six breeds belonged to two different maternal lineage, one included Xianju chicken and White Leghorn chicken which had the same maternal origin, the other included Lingkun chicken, Baiyiner chicken, Wugu chicken and Xiaoshan chicken which had the same matriarchic ancestor. Among the latter lineage, Lingkun chicken, Baiyiner chicken and Wugu chicken had a closer relationship to each other than to Xiaoshan chicken.
- Published
- 2001
46. [Expression pattern of mRNA for follistatin and inhibin/activin beta B-subunit during follicular and testicular development in duck].
- Author
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Fu Y, Niu D, Ruan H, Yu XP, Chen G, He GQ, and Yang PX
- Subjects
- Animals, Ducks, Female, Follistatin, Male, Reverse Transcriptase Polymerase Chain Reaction, Activins, Glycoproteins genetics, Inhibins genetics, Ovarian Follicle metabolism, Peptides genetics, RNA, Messenger analysis, Testis metabolism
- Abstract
Follistatin and inhibin/activin were closely related glycoprotein hormones. The quantitative competitive RT-PCR was used to investigate the expression of follistatin and inhibin/activin beta B-subunit mRNA in the developing ovarian follicles, immature and mature testes. The results revealed all samples showed the expression of mRNA for the two proteins, and the expression is more abundantly in the small follicles than in the large preovulatory follicles. Competitive RT-PCR revealed that the expression of follistatin is the highest in small yellow follicles (SYF), the mean relative content for the F1, F2, F3, F4, F5, F6-8, LWF (large white follicle), TI(immature testes), and TM(mature testes) was 0.011 +/- 0.004, 0.019 +/- 0.006, 0.021 +/- 0.009, 0.028 +/- 0.007, 0.075 +/- 0.023, 0.15 +/- 0.072, 0.29 +/- 0.068, 0.037 +/- 0.011, and 0.012 +/- 0.004, respectively, compared to a mean relative content of 1.00 for the SYF. The highest level of inhibin/activin beta B mRNA was also found in the SYF, the mean relative content for the F1, F2, F3, F4, F5, F6-8, LWF, TI, and TM was 0.009 +/- 0.003, 0.013 +/- 0.005, 0.019 +/- 0.007, 0.023 +/- 0.006, 0.29 +/- 0.084, 0.84 +/- 0.093, 0.031 +/- 0.008, 0.38 +/- 0.072, and 0.046 +/- 0.013, respectively, compared to a mean relative content of 1.00 for the SYF. Our data suggested that the expression pattern of mRNA for follistatin and inhibin/activin beta B-subunit was quite similar during follicular and testicular development. The great co-expression of mRNA for the two proteins in small follicles indicated that activin B(beta B-beta B) availability was tightly regulated by follistatin, and the two proteins might both play important roles in early follicular development.
- Published
- 2001
47. [Expression of inhibin alpha and inhibin/activin beta A subunits in the developing follicles of the duck].
- Author
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Fu Y, Niu D, Ruan H, Yu XP, Chen G, He GQ, and Yang PX
- Subjects
- Animals, Female, Reverse Transcriptase Polymerase Chain Reaction, Ducks genetics, Inhibin-beta Subunits, Inhibins genetics, Ovarian Follicle metabolism, RNA, Messenger analysis
- Abstract
The very sensitive quantitative competitive reverse transcription-polymerase chain reaction (RT-PCR) was used to investigate the expression of mRNA for the inhibin alpha and inhibin/activin beta A subunit in the developing ovarian follicles of the duck. The results indicated all follicles showed the expression of mRNA for the inhibin alpha and inhibin/activin beta A. The inhibin alpha subunit mRNA is expressed more abundantly than the beta A subunit in the large preovulatory follicles. Competitive RT-PCR revealed that the expression of inhibin alpha subunit is the highest in small yellow follicles (SYF), the mean relative content for the F1, F2, F3, F4/5 and LWF (large white follicle) was 0.26 +/- 0.05, 0.28 +/- 0.07, 0.57 +/- 0.12, 0.98 +/- 0.09 and 0.026 +/- 0.006, respectively, compared to a mean relative content of 1.00 for the SYF. The highest level of inhibin/activin beta A mRNA was found in the F1 follicle, the mean relative content for the F2, F3, F4/5, SYF and LWF was 0.218 +/- 0.09, 0.111 +/- 0.03, 0.058 +/- 0.011, 0.053 +/- 0.013 and 0.005 +/- 0.002, respectively, compared to a mean relative content of 1.00 for the F1 follicle. Our data suggest that the expression of the alpha subunit is reduced with follicular development whereas beta A subunit expression is dramatically enhanced, which indicates the expression of inhibin alpha and inhibin/activin beta A subunit is differentially regulated during follicular development. In addition, the highest level of beta A mRNA in F1 follicle indicates the production of dimeric inhibin and/or activin primarily occurred in the largest F1 follicle.
- Published
- 2001
48. [Effects of activin and follistatin on FSH receptor mRNA expression of cultured Shao duck granulosa cells].
- Author
-
Fu Y, Niu D, Ruan H, Yu XP, Chen G, and He GQ
- Subjects
- Animals, Cells, Cultured, Ducks, Female, Follicle Stimulating Hormone pharmacology, Follistatin, Granulosa Cells metabolism, Activins pharmacology, Granulosa Cells drug effects, RNA, Messenger analysis, Receptors, FSH genetics
- Abstract
The aim of this study was to investigate the action of activin and follistatin either alone or in combination on FSH receptor mRNA expression. The results showed that activin alone increased FSH receptor mRNA level in the presence or absence of FSH in cultured granulosa cells, and the stimulating effect of activin on FSH receptor level was dose-dependent. This effect of activin was inhibited by FSP treatment which alone had no effect on FSH receptor expression. From the results, it can be concluded that activin and follistatin both exert autocrine actions on granulosa cells, and the two factors, possibly by regulating FSH receptor expression, may play important roles in follicular development.
- Published
- 2001
49. A new subdivision of mammalian neostriatum with functional implications to learning and memory.
- Author
-
Shu SY, Bao X, Li S, Niu D, Xu Z, and Li Y
- Subjects
- Animals, Humans, Image Processing, Computer-Assisted, Immunohistochemistry, Male, Maze Learning physiology, Rats, Species Specificity, Stimulation, Chemical, Brain Mapping, Cats physiology, Learning physiology, Macaca physiology, Memory physiology, Neostriatum physiology, Rats, Sprague-Dawley physiology
- Abstract
A new subdivision with distinctive morphological and functional attributes has been identified at the caudomedial margin of the neostriatum and surrounding the rostrolateral border of the globus pallidus in the brains of the rat, cat, monkey, and human. The subdivision is termed marginal division (MrD) based on its location. It is readily distinguishable from the rest of striatum by consisting of spindle-shaped neurons, special connections, and intensely expressed immunoreactivities of many neuropeptides and some monoamines in the fibers, terminals, and neuronal somata. Three-dimensional reconstruction from Nissl-stained sections of the rat brain revealed that the MrD is a flat, pan-shaped zone between the neostriatum and globus pallidus. Functional neuronal connections were delineated by chemical-induced c-Fos expression between the MrD and hippocampus, amygdala, as well as the basal nucleus of Meynert. In rats with chemical lesions of bilateral MrD, learning and memory functions were severely impaired as demonstrated by double blind Y-maze test. Our results thus suggested that the MrD is a distinct part and a universal structure in the neostriatum of the mammalian brain and might play an important role in the mechanism of learning and memory., (Copyright 1999 Wiley-Liss, Inc.)
- Published
- 1999
50. Regeneration of transgenic Lycium barbarum L.
- Author
-
Wang H, Huang F, Li A, Shao Q, and Niu D
- Subjects
- Kanamycin pharmacology, Kanamycin Kinase, Kanamycin Resistance genetics, Plants, Genetically Modified anatomy & histology, Plants, Genetically Modified enzymology, Plants, Genetically Modified genetics, Plants, Medicinal genetics, Plants, Medicinal growth & development, Phosphotransferases genetics, Plants, Genetically Modified growth & development, Transformation, Genetic
- Abstract
A simple and effective system for the transformation and regeneration of Lycium barbarum L. has been developed. Young stem segments from Lycium barbarum L. were infected by Agrobacterium tumefaciens harboring a vector containing neomycin phosphotransferase II (npt-II) gene derived from non-oncogenic Ti plasmid. Calli originating from young stem segments on selective induction medium could differentiate into buds on selective differentiation medium rapidly and finally developed into whole plants. NPT-II enzyme activity assay and DNA hybridization indicated that the foreign gene had been integrated into the genome of Lycium barbarum L. and could be expressed in plants.
- Published
- 1991
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