63 research outputs found

    Evaluation of the Ecological Quality of the Taishan Region Based on Landsat Series of Satellite Images

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    The deterioration of ecological environment has seriously restricted regional sustainable development. Taishan region is one of the ecological protection and restoration of life community of mountains-rivers-forests-farmlands-lakes-grasslands in China. Its ecological quality changes are directly related to the overall layout of ecological restoration and protection projects. In this study, the Taishan region of China was taken as study area, and the grade change, spatial distribution, and spatial temporal fluctuation of the ecological environment quality were quantified. Based on the ENVI platform, the Landsat series of three images of the Taishan region in 2005, 2013, and 2017 serve as the data source, and the remote sensing ecological index model (RSEI) was used. According to the change characteristics of land use types, the driving factors of ecological environmental quality change were analyzed. The results showed that: (1) The area ratio of the ecological environment quality above the middle level was in order from large to small: 2005 (97.37%) > 2017 (91.46%) > 2013 (84.64%). (2) The overall quality of the ecological environment declined during the period of 2005-2013. (3) The overall change ranges from 2013 to 2017 are smaller than those from 2005 to 2013. The area of the deteriorating area decreased by 44.90%, and the area of the constant area and the area of the area that improved increased by 16.17% and 28.72%, respectively. During 2013-2017, the general trend is getting better and better. The improved areas were mainly concentrated in the main urban areas (Taishan District, Daiyue District), eastern Ningyang County, and western Xintai City. The research results can provide a scientific basis for the scientific evaluation of the ecological environment quality during the development and construction of the region, and have important value in the design and application of the ecological environment quality optimization path

    An Evaluation of Immobilized Poly-(S)-N-(1-phenylethyl)acrylamide Chiral Stationary Phases

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    In this study, brush type and polymer type stationary phases were prepared based on (S)-N-(1-phenylethyl) acrylamide, and the polymeric stationary phase demonstrated superior chiral recognition ability. The two polymeric stationary phases were synthesized by two strategies, one was the “grafting from” method, which obtained polymer CSP by initiating monomer polymerization on the surface of 3-methacrylatepropyl silica gel, and the other was “grafting to”, which fixed the copolymer of (S)-N-(1-phenylethyl) acrylamide and trimethoxysilylpropyl methacrylate on silica gel. A comparison of these two bonding modes revealed that the stationary phase produced by “grafting to” had higher chiral recognition ability. Further improvement can be achieved by the end-capping of silanol groups with trimethylchlorosilane to reduce non-enantioselective retention caused by residual silanol groups and improve the peak shape of enantiomers. Chiral separation in subcritical fluid chromatography was also studied. Similar enantioselectivity results with higher resolution were observed due to the improvement of peak shape

    An Evaluation of Immobilized Poly-(<i>S</i>)-<i>N</i>-(1-phenylethyl)acrylamide Chiral Stationary Phases

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    In this study, brush type and polymer type stationary phases were prepared based on (S)-N-(1-phenylethyl) acrylamide, and the polymeric stationary phase demonstrated superior chiral recognition ability. The two polymeric stationary phases were synthesized by two strategies, one was the “grafting from” method, which obtained polymer CSP by initiating monomer polymerization on the surface of 3-methacrylatepropyl silica gel, and the other was “grafting to”, which fixed the copolymer of (S)-N-(1-phenylethyl) acrylamide and trimethoxysilylpropyl methacrylate on silica gel. A comparison of these two bonding modes revealed that the stationary phase produced by “grafting to” had higher chiral recognition ability. Further improvement can be achieved by the end-capping of silanol groups with trimethylchlorosilane to reduce non-enantioselective retention caused by residual silanol groups and improve the peak shape of enantiomers. Chiral separation in subcritical fluid chromatography was also studied. Similar enantioselectivity results with higher resolution were observed due to the improvement of peak shape

    Kub3 Deficiency Causes Aberrant Late Embryonic Lung Development in Mice by the FGF Signaling Pathway

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    As a Ku70-binding protein of the KUB family, Kub3 has previously been reported to play a role in DNA double-strand break repair in human glioblastoma cells in glioblastoma patients. However, the physiological roles of Kub3 in normal mammalian cells remain unknown. In the present study, we generated Kub3 gene knockout mice and revealed that knockout (KO) mice died as embryos after E18.5 or as newborns immediately after birth. Compared with the lungs of wild-type (WT) mice, Kub3 KO lungs displayed abnormal lung morphogenesis and pulmonary atelectasis at E18.5. No difference in cell proliferation or cell apoptosis was detected between KO lungs and WT lungs. However, the differentiation of alveolar epithelial cells and the maturation of type II epithelial cells were impaired in KO lungs at E18.5. Further characterization displayed that Kub3 deficiency caused an abnormal FGF signaling pathway at E18.5. Taking all the data together, we revealed that Kub3 deletion leads to abnormal late lung development in mice, resulting from the aberrant differentiation of alveolar epithelial cells and the immaturation of type II epithelial cells due to the disturbed FGF signaling pathway. Therefore, this study has uncovered an essential role of Kub3 in the prenatal lung development of mice which advances our knowledge of regulatory factors in embryonic lung development and provides new concepts for exploring the mechanisms of disease related to perinatal lung development

    T1121G Point Mutation in the Mitochondrial Gene <i>COX1</i> Suppresses a Null Mutation in <i>ATP23</i> Required for the Assembly of Yeast Mitochondrial ATP Synthase

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    Nuclear-encoded Atp23 was previously shown to have dual functions, including processing the yeast Atp6 precursor and assisting the assembly of yeast mitochondrial ATP synthase. However, it remains unknown whether there are genes functionally complementary to ATP23 to rescue atp23 null mutant. In the present paper, we screen and characterize three revertants of atp23 null mutant and reveal a T1121G point mutation in the mitochondrial gene COX1 coding sequence, which leads to Val374Gly mutation in Cox1, the suppressor in the revertants. This was verified further by the partial restoration of mitochondrial ATP synthase assembly in atp23 null mutant transformed with exogenous hybrid COX1 T1121G mutant plasmid. The predicted tertiary structure of the Cox1 p.Val374Gly mutation showed no obvious difference from wild-type Cox1. By further chase labeling with isotope [35S]-methionine, we found that the stability of Atp6 of ATP synthase increased in the revertants compared with the atp23 null mutant. Taking all the data together, we revealed that the T1121G point mutation of mitochondrial gene COX1 could partially restore the unassembly of mitochondrial ATP synthase in atp23 null mutant by increasing the stability of Atp6. Therefore, this study uncovers a gene that is partially functionally complementary to ATP23 to rescue ATP23 deficiency, broadening our understanding of the relationship between yeast the cytochrome c oxidase complex and mitochondrial ATP synthase complex

    Mixed-effects varying-coefficient model with skewed distribution coupled with cause-specific varying-coefficient hazard model with random-effects for longitudinal-competing risks data analysis

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    © 2016 Taylor & Francis. It is well known that there is strong relationship between HIV viral load and CD4 cell counts in AIDS studies. However, the relationship between them changes during the course of treatment and may vary among individuals. During treatments, some individuals may experience terminal events such as death. Because the terminal event may be related to the individuals viral load measurements, the terminal mechanism is non-ignorable. Furthermore, there exists competing risks from multiple types of events, such as AIDS-related death and other death. Most joint models for the analysis of longitudinal-survival data developed in literatures have focused on constant coefficients and assume symmetric distribution for the endpoints, which does not meet the needs for investigating the nature of varying relationship between HIV viral load and CD4 cell counts in practice. We develop a mixed-effects varying-coefficient model with skewed distribution coupled with cause-specific varying-coefficient hazard model with random-effects to deal with varying relationship between the two endpoints for longitudinal-competing risks survival data. A fully Bayesian inference procedure is established to estimate parameters in the joint model. The proposed method is applied to a multicenter AIDS cohort study. Various scenarios-based potential models that account for partial data features are compared. Some interesting findings are presented

    Nonoxynol-9 berberine plural gel has little effect on expression of SLPI, SP-D and lactoferrin in mice’s vagina

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    Background: The most frequently used spermicide Nonoxynol-9 (N-9) in the clinic alters the vaginal flora, which will result in an increased risk of opportunistic infection. So development of a novel spermicidal and microbicidal drug appears to be inevitable. Vaginal local immune is an important part of vaginal flora. Secretory leukocyte protease inhibitor (SLPI), surfactant proteins D (SP-D), and lactoferrin (LF) are anti-microbial molecules with important roles in immune system of female vaginas. Objective: To observe effect of a vaginal spermicide nonoxynol-9 (N-9) berberine plural gel on the expression of SLPI SP-D and LF in mice’s vaginas. Materials and Methods: Female BABL/C mice were randomly divided into following 5 groups: normal control group, blank gel group, berberine gel group, 12% N-9 gel group and N-9 berberine plural gel group. Estradiol benzoate at physiological dose was done by hypodermic injection to every group’s mice. After 72h, drug gels were separately injected into the mice’s vaginas, while immunohistochemistry and Western blot were taken to detect the expression of the 3 indexes in mice’s vaginas respectively after 24h and 72h of gel injection. Results: The differences in the three indexes between normal control group and blank gel group were not significant statistically (p>0.05). The expression of the three indexes in 12% N-9 gel group was decreased compared to that in blank gel group (p<0.05). The differences in the three indexes between N-9 berberine plural gel group and blank gel group were not significant statistically (p>0.05). Also, the three index's level of 24h and 72h in sub observation groups after treatment were without statistical significance (p>0.05). Conclusion: Application of N-9 berberine plural gel had little impact on antimicrobial peptides in normal mice’s vaginas

    High-Resolution Displacement Sensor Based on a Chirped Fabry–Pérot Interferometer Inscribed on a Tapered Microfiber

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    In this study, a high-resolution optical fiber Fabry&#8315;P&#233;rot (FP) interferometer displacement sensor with chirped spectral characteristics based on a tapered microfiber is theoretically discussed and experimentally implemented. Instead of inscribing two fiber Bragg gratings (FBGs) on the symmetric position of the microfiber, we continuously inscribed one long FBG along the microfiber region to reduce the cavity length. The bandwidth of the interferometer is over 35 nm, and its displacement sensitivity is as high as 36.5 nm/mm at the tension state

    Cetuximab Enhanced the Cytotoxic Activity of Immune Cells during Treatment of Colorectal Cancer

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    Background/Aims: Cetuximab is a chimeric IgG1 monoclonal antibody which targets the extracellular domain of epidermal growth factor receptor. This antibody is widely used for colorectal cancer (CRC) treatment but its influence on the immune system is incompletely understood. Methods: The immune influence of cetuximab therapy in CRC patients was investigated by analyzing peripheral blood mononuclear cells using flow cytometry. We undertook in vitro cytotoxicity and cytokine-profile assays to ascertain the immunomodulatory effect of cetuximab treatment. Results: The number of CD3+ T, CD8+ T, and natural killer (NK) cells was increased significantly and T-regulatory cells reduced gradually after cetuximab treatment. Percentage of CD4+ T, natural killer T (NKT)-like, invariant NKT, and dendritic cells was similar between baseline patients and cetuximab patients. Expression of CD137 on NK and CD8+ T cells was increased significantly after 4 weeks of cetuximab therapy. In vitro cetuximab treatment markedly increased expression of CD137 and CD107a on NK and CD8+ T cells. Cetuximab treatment promoted the cytotoxic activity of NK and CD8+ T cells against tumor cells. Conclusion: Cetuximab treatment promotes activation of the immune response but alleviates immunosuppression: this might be the underlying anti-CRC effect of cetuximab
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