[Objective] The aims were to construct a new suicide plasmid of Lactobacillus and gene deletion engineering bacteria of Lactobacillus with pUC19 vector. [Methods] pUC19-CM was constructed by inserting a chloramphenico...[Objective] The aims were to construct a new suicide plasmid of Lactobacillus and gene deletion engineering bacteria of Lactobacillus with pUC19 vector. [Methods] pUC19-CM was constructed by inserting a chloramphenicol resistant gene into the multi-cloning site of pUC19,and then two homologous fragments were cloned into each side of the pUC19-CM to construct suicide plasmid pUC19-CM-D. [Results] A replacement mutant strain,whose target gene was replaced by resistant gene,could be obtained by transforming the suicide plasmid pUC19-CM-D into Lactobacillus for resistance screening. [Conclusion] The construction and application of pUC19-CM-D provided a fast and efficient means of construction of gene deletion engineering bacteria of Lactobacillus,and laid a foundation for study of gene function of Lactobacillus.展开更多
We investigate the position dependent spontaneous emission spectra of a A-type three-level atom with one transition coupled to the free vacuum reservoir and the other one coupled to a double-band photonic band gap res...We investigate the position dependent spontaneous emission spectra of a A-type three-level atom with one transition coupled to the free vacuum reservoir and the other one coupled to a double-band photonic band gap reservoir with a defect mode in the band gap. It is shown that, for the atom at the defect location, we have a two-peak spectrum with a wide dark line due to the strong coupling between the atom and the defect mode. While, when the atom is far from the defect location （or in the absence of the defect mode）, the spectrum has three peaks with two dark lines due to the coupling between the atom and the photonic band gap reservoir with the largest density of states near the band edges. On the other hand, we have a four-peak spectrum for the atom at the space in between. Moreover, the average spontaneous emission spectra of the atoms uniformly embedded in high dielectric or low dielectric regions are described. It is shown that the atoms embedded in high （low） dielectric regions far from the defect location, effectively couple to the modes of the lower （upper） photonic band. However, the atoms embedded in high dielectric or low dielectric regions at the defect location, are coupled mainly to the defect modes. While, the atoms uniformly embedded in high （low） dielectric regions with a normal distance from the defect location, are coupled to both of defect and lower （upper） photonic band modes.展开更多
The dielectric functions of GaN for the temperature and frequency ranges of 10–300 K and 0.3–1 THz are obtained using terahertz time-domain spectroscopy.It is found that there are oscillations of the dielectric func...The dielectric functions of GaN for the temperature and frequency ranges of 10–300 K and 0.3–1 THz are obtained using terahertz time-domain spectroscopy.It is found that there are oscillations of the dielectric functions at various temperatures.Physically,the oscillation behavior is attributed to the resonance states of the point defects in the material.Furthermore,the dielectric functions are well fitted by the combination of the simple Drude model together with the classical damped oscillator model.According to the values of the fitting parameters,the concentration and electron lifetime of the point defects for various temperatures are determined,and the temperature dependences of them are in accordance with the previously reported result.Therefore,terahertz time-domain spectroscopy can be considered as a promising technique for investigating the relevant characteristics of the point defects in semiconductor materials.展开更多
A series of 2-arylamino-1,3,5-triazine derivatives(4a–4g),which were designed and synthesized via Sonogashira coupling reaction,were evaluated using two-electrode voltage clamp(TEVC)recordings of humanα7 nAChR expre...A series of 2-arylamino-1,3,5-triazine derivatives(4a–4g),which were designed and synthesized via Sonogashira coupling reaction,were evaluated using two-electrode voltage clamp(TEVC)recordings of humanα7 nAChR expressed in Xenopus ooctyes.Compound 4g as a positive allosteric modulator(PAM)showed better efficacy than lead compound 3(HZZ-A-11)with an EC50 value of 1.23±0.41μM.Further pharmacological evaluation of compound 4g might lead to the developmental potential for therapy of cognitive deficits commonly shared by neuropsychiatric disorders,such as schizophrenia and Alzheimer’s disease.展开更多
基金Supported by National Science &Technology Pillar Program in the Eleventh Five-year Plan Period (2007BAD75B06)Guangxi Sci-ence Foundation (0782003-4)~~
文摘[Objective] The aims were to construct a new suicide plasmid of Lactobacillus and gene deletion engineering bacteria of Lactobacillus with pUC19 vector. [Methods] pUC19-CM was constructed by inserting a chloramphenicol resistant gene into the multi-cloning site of pUC19,and then two homologous fragments were cloned into each side of the pUC19-CM to construct suicide plasmid pUC19-CM-D. [Results] A replacement mutant strain,whose target gene was replaced by resistant gene,could be obtained by transforming the suicide plasmid pUC19-CM-D into Lactobacillus for resistance screening. [Conclusion] The construction and application of pUC19-CM-D provided a fast and efficient means of construction of gene deletion engineering bacteria of Lactobacillus,and laid a foundation for study of gene function of Lactobacillus.
文摘We investigate the position dependent spontaneous emission spectra of a A-type three-level atom with one transition coupled to the free vacuum reservoir and the other one coupled to a double-band photonic band gap reservoir with a defect mode in the band gap. It is shown that, for the atom at the defect location, we have a two-peak spectrum with a wide dark line due to the strong coupling between the atom and the defect mode. While, when the atom is far from the defect location （or in the absence of the defect mode）, the spectrum has three peaks with two dark lines due to the coupling between the atom and the photonic band gap reservoir with the largest density of states near the band edges. On the other hand, we have a four-peak spectrum for the atom at the space in between. Moreover, the average spontaneous emission spectra of the atoms uniformly embedded in high dielectric or low dielectric regions are described. It is shown that the atoms embedded in high （low） dielectric regions far from the defect location, effectively couple to the modes of the lower （upper） photonic band. However, the atoms embedded in high dielectric or low dielectric regions at the defect location, are coupled mainly to the defect modes. While, the atoms uniformly embedded in high （low） dielectric regions with a normal distance from the defect location, are coupled to both of defect and lower （upper） photonic band modes.
基金supported by the Special Funds for Major State Basic Research Project (Grant No. 2011CB301900)the 973 project of the Ministry of Science and Technology of China (Grant No. 2011CBA00107)+4 种基金the Hi-tech Research Project (Grant No. 2011AA03A103)the National Natural Science Foundation of China (Grant Nos. 60990311, 60820106003, 60906025, 60936004, 61176063, 61071009, and 61027008)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20090091110040)the Natural Science of Foundation of Jiangsu province (Grant Nos. BK2011010, BK2010385, and BK2010178)the Fok Ying-Tong Education Foundation (Grant No. 122028)
文摘The dielectric functions of GaN for the temperature and frequency ranges of 10–300 K and 0.3–1 THz are obtained using terahertz time-domain spectroscopy.It is found that there are oscillations of the dielectric functions at various temperatures.Physically,the oscillation behavior is attributed to the resonance states of the point defects in the material.Furthermore,the dielectric functions are well fitted by the combination of the simple Drude model together with the classical damped oscillator model.According to the values of the fitting parameters,the concentration and electron lifetime of the point defects for various temperatures are determined,and the temperature dependences of them are in accordance with the previously reported result.Therefore,terahertz time-domain spectroscopy can be considered as a promising technique for investigating the relevant characteristics of the point defects in semiconductor materials.
基金National Natural Science Foundation of China aw arded to Q.Sun(NSFC,Grant No.81973169,21572011)and K.W.Wang(NSFC,Grant No.81537410)the Ministry of Science and Technology of China to K.W.Wang(Grant No.2014ZX09507003-006-004)。
文摘A series of 2-arylamino-1,3,5-triazine derivatives(4a–4g),which were designed and synthesized via Sonogashira coupling reaction,were evaluated using two-electrode voltage clamp(TEVC)recordings of humanα7 nAChR expressed in Xenopus ooctyes.Compound 4g as a positive allosteric modulator(PAM)showed better efficacy than lead compound 3(HZZ-A-11)with an EC50 value of 1.23±0.41μM.Further pharmacological evaluation of compound 4g might lead to the developmental potential for therapy of cognitive deficits commonly shared by neuropsychiatric disorders,such as schizophrenia and Alzheimer’s disease.
