839 research outputs found
Plasmid encoding matrix protein of vesicular stomatitis viruses as an antitumor agent inhibiting rat glioma growth in situ
Aim: Oncolytic effect of vesicular stomatitis virus (VSV) has been proved previously. Aim of the study is to investigate glioma inhibition effect of Matrix (M) protein of VSV in situ. Materials and Methods: A recombinant plasmid encoding VSV M protein (PM) was genetically engineered, and then transfected into cultured C6 gliomas cells in vitro. C6 transfected with Liposome-encapsulated PM (LEPM) was implanted intracranially for tumorigenicity study. In treatment experiment, rats were sequentially established intracranial gliomas with wild-typed C6 cells, and accepted LEPM injection intravenously. Possible mechanism of M protein was studied by using Hoechst staining, PI-stained flow cytometric analysis, TUNEL staining and CD31 staining. Results: M protein can induce generous gliomas lysis in vitro. None of the rats implanted with LEPM-treated cells developed any significant tumors, whereas all rats in control group developed tumors. In treatment experiment, smaller tumor volume and prolonged survival time was found in the LEPM-treated group. Histological studies revealed that possible mechanism were apoptosis and anti-angiogenesis. Conclusion: VSV-M protein can inhibit gliomas growth in vitro and in situ, which indicates such a potential novel biotherapeutic strategy for glioma treatment.Цель: изучить способность матриксного протеина (М протеина) вируса везикулярного стоматита (ВВС) угнетать рост глиомы
in situ. Материалы и методы: сконструирована рекомбинантная плазмида, кодирующая М протеин ВВС, которая затем была
трансфецирована в культивированные клетки глиомы С6 in. Клетки глиомы С6, трансфецированные инкапсулированным
в липосомы М протеином (ЛИМП), имплантировали интракраниально для изучения туморогенности. В эксперименте крысам
с трансплантированной интракраниально глиомой С6 (исходный штамм) внутривенно вводили ЛИМП. Апоптотическое действие
М протеина на опухолевые клетки изучали с применением флуоресценцентной микроскопии (окрашивание по Хехсту),
проточной цитометрии (окрашивание пропидиумом йодидом), TUNEL васкуляризацию опухоли оценивали гистологически и васкуляризацию опухоли оценивали гистологически и
иммуногистохимически с применением анти-CD31 моноклональных антител. 31 моноклональных антител. 31 моноклональных антител. Результаты: М протеин может индуцировать
лизис клеток глиомы in. Ни у одного животного с трансплантированными клетками глиомы, обработанными ЛИМП,
не возникали опухоли значительного размера, тогда как у всех крыс из контрольной группы опухоли развивались. В группе
животных, которым вводили ЛИМП, опухоли были меньшего объема и отмечали увеличение продолжительности жизни
животных. Показано, что М протеин проявляет антиангиогенные свойства и обладает способностью индуцировать апоптоз.
Выводы: М протеин ВВС ингибирует рост глиомы in и in. На этой основе может быть разработана потенциально новая
биотерапевтическая стратегия для лечения пациентов с глиомами
Long-range and high-resolution correlation optical time-domain reflectometry utilizing an all optical chaotic source
A high resolution optical time domain reflectometry (OTDR) based on an all-fiber chaotic source is demonstrated. We analyze the key factors limiting the operational range of such an OTDR, e.g., integral Rayleigh backscattering and the fiber loss, which degrade the optical signal to noise ratio at the receiver side, and then the guideline for counter-act such signal fading is discussed. The experimentally demonstrated correlation OTDR presents ability of 100km sensing range and 8.2cm spatial resolution (1.2 million resolved points), as a verification of the theoretical analysis. To the best of our knowledge, this is the first time that correlation OTDR measurement is performed over such a long distance with such high precision
High resolution optical time-domain reflectometry based on correlation utilizing an all-fiber chaotic source
We propose a high-resolution optical time domain reflectometry (OTDR) based on an all-fiber supercontinuum source. The source simply consists of a laser with moderate power and a section of fiber which has a zero dispersion wavelength near the laser's central wavelength. Spectrum and time domain properties of the source are investigated, showing that the source has great capability in nonlinear optics, such as correlation OTDR. We analyze one of the key factors limiting the operational range of such an OTDR, i.e., sampling time. Finally, we experimentally demonstrate a correlation OTDR with 25km sensing range and 5.3cm spatial resolution, as a verification of theoretical analysis
Respuestas del δ13C foliar y características foliares a la precipitación y temperatura en un ecosistema árido del noroeste de China
El δ13C foliar es ampliamente usado para explicar estrategias relacionadas con la disponibilidad de recursos en diferentes ambientes. Sin embargo, la respuesta conjunta del δ13C foliar a la precipitación y temperatura así como la relación entre el δ13C foliar y las características foliares no están claras. El δ13C foliar y su relación con las características foliares [tamaño de hoja (LS), longitud foliar (LL), ancho foliar (LW), relación entre la longitud y el ancho foliar (L:W), área foliar específica (SLA) y concentración de N foliar (en una base de peso seco) (Nmass)] fueron investigadas en la especie de arbusto dominante Nitraria tangutorum Bobr en la región árida (Dengkou y Minqin) del noroeste de China. El estudio se efectuó bajo condiciones de varias cantidades de precipitación simuladas (PGS) y temperaturas ambientales (TGS) en las estaciones de crecimiento de 2008, 2009 y 2010. Los resultados mostraron que LS, LW, LL, SLA y Nmass se incrementaron significativamente cuando las cantidades de PGS se incrementaron, pero hubo tendencias de reducción en dichas características cuando las TGS aumentaron. Sin embargo, la mayoría de las relaciones negativas entre las características foliares y las TGS no fueron obvias en Minqin. En ambos sitios, L:W se incrementó cuando las PGS y TGS aumentaron. Hubo un cambio en la relación negativa entre el δ13C foliar-PGS a través de Minqin y Dengkou, lo cual condujo a la falta de efectos de la precipitación en el δ13C foliar a través de ambos sitios, y mayor δ13C foliar a menor precipitación en Minqin. A través de Minqin y Dengkou, PGS solo pudo explicar un 14% de la variación en el δ13C foliar. La combinación de PGS y TGS pudo explicar un 64% de la variación en el δ13C foliar. Las características foliares (LW y L:W) mejoraron aún más la estimación del δ13C foliar. Las combinaciones de PGS, TGS, LW y L:W pudieron explicar un 84% de la variación en el δ13C foliar. Nuestro estudio demostró la importancia de las características foliares en explorar las respuestas del δ13C foliar a cambios globales en ecosistemas áridos.Leaf δ13C is widely used to explain plant strategies related to resource availability in different environments. To understand the coupled response of leaf δ13C to precipitation, temperature and the relationship between leaf δ13C and leaf traits in arid ecosystems, the leaf δ13C and leaf traits (leaf size (LS), leaf length (LL), leaf width (LW), leaf length to width ratio (L:W), specific leaf area (SLA) and mass-based leaf nitrogen concentration (Nmass)) of Nitraria tangutorum Bobr. under simulated increasing precipitation (PGS) and ambient temperature (TGS) in plant growing season from 2008 to 2010 and the relationships between leaf δ13C and leaf traits were investigated in the arid region (Dengkou and Minqin) of northwestern China. Our results showed that LS, LW, LL, SLA and Nmass significantly increased with increasing PGS, but had downward tendencies with increasing TGS although the majority of the negative relationships between leaf traits and TGS were not obvious in Minqin. At the two study sites, L:W increased simultaneously with increasing PGS and TGS. There was a shift in the negative leaf δ13C-PGS relationship across Minqin and Dengkou, which conduce to the lacking effect of precipitation on leaf δ13C across the two sites and higher leaf δ13C in lower precipitation fields in Minqin. Across Minqin and Dengkou, PGS could only explain 14% of the variation in leaf δ13C. The combinations of PGS and TGS could explain 64% of the variation in leaf δ13C. Leaf traits (LW and L:W) could be used to further improve the estimation of leaf δ13C. The combinations of PGS, TGS, LW and L:W could explain 84 % of the variation in leaf δ13C. Our study demonstrated the importance of leaf traits in exploring the responses of leaf δ13C to global changes in arid ecosystems.Fil: Xin, Z.M.. Chinese Academy of Forestry. Institute of Desertification Studies; China. Chinese Academy of Forestry. Experimental Center of Desert Forestry; ChinaFil: Liu, M.H.. Chinese Academy of Forestry. Experimental Center of Desert Forestry; ChinaFil: Lu, Q.. Chinese Academy of Forestry. Institute of Desertification Studies; China. State Forestry Administration. Kumtag Desert Ecosystem Research Station; ChinaFil: Busso, Carlos Alberto. Universidad Nacional del Sur. Departamento de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. State Forestry Administration. Kumtag Desert Ecosystem Research Station; ChinaFil: Zhu, Y.J.. State Forestry Administration. Kumtag Desert Ecosystem Research Station; China. Chinese Academy of Forestry. Institute of Desertification Studies; ChinaFil: Li, Z.. Chinese Academy of Forestry. Experimental Center of Desert Forestry; ChinaFil: Huang, Y.R.. Chinese Academy of Forestry. Experimental Center of Desert Forestry; ChinaFil: Li, X.L.. Chinese Academy of Forestry. Experimental Center of Desert Forestry; ChinaFil: Luo, F.M.. Chinese Academy of Forestry. Experimental Center of Desert Forestry; ChinaFil: Bao, F.. Chinese Academy of Forestry. Institute of Desertification Studies; ChinaFil: Qian, J.Q.. Henan Agricultural University. College of Forestry; ChinaFil: Li, Y.H.. Chinese Academy of Forestry. Institute of Desertification Studies; China. State Forestry Administration. Kumtag Desert Ecosystem Research Station; Chin
Direct Measurements of the Branching Fractions for and and Determinations of the Form Factors and
The absolute branching fractions for the decays and
are determined using singly
tagged sample from the data collected around 3.773 GeV with the
BES-II detector at the BEPC. In the system recoiling against the singly tagged
meson, events for and events for decays are observed. Those yield
the absolute branching fractions to be and . The
vector form factors are determined to be
and . The ratio of the two form
factors is measured to be .Comment: 6 pages, 5 figure
Measurements of the Mass and Full-Width of the Meson
In a sample of 58 million events collected with the BES II detector,
the process J/ is observed in five different decay
channels: , , (with ), (with
) and . From a combined fit of all five
channels, we determine the mass and full-width of to be
MeV/ and
MeV/.Comment: 9 pages, 2 figures and 4 table. Submitted to Phys. Lett.
The pole in
Using a sample of 58 million events recorded in the BESII detector,
the decay is studied. There are conspicuous
and signals. At low mass, a large
broad peak due to the is observed, and its pole position is determined
to be - MeV from the mean of six analyses.
The errors are dominated by the systematic errors.Comment: 15 pages, 6 figures, submitted to PL
Search for the Lepton Flavor Violation Processes and
The lepton flavor violation processes and are
searched for using a sample of 5.8 events collected with
the BESII detector. Zero and one candidate events, consistent with the
estimated background, are observed in and
decays, respectively. Upper limits on the branching ratios are determined to be
and at the 90% confidence level (C.L.).Comment: 9 pages, 2 figure
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